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BI256 Overview
13 Flashcard Decks
Chordate Flashcards
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What are the characteristics of a closed circulatory system?
Segmentation, if present, is restricted to the outer body wall, head, and tail, and does not extend into the coelom.
What is the first chordate hallmark mentioned in the text?
Notochord: a flexible rodlike structure extending the length of the body, functioning as a hydrostatic organ and the axis for muscle attachment.
How does the notochord facilitate movement in primitive chordates?
It bends without shortening, allowing undulatory body movement, akin to hydraulic pressure locomotion like fish swimming side to side.
Describe the characteristics of the dorsal nerve cord as a chordate hallmark.
It is always dorsal to the gastrointestinal tract, initially tubular and hollow in most invertebrates, and enlarged at the anterior end to form the brain in most chordates.
What structures are formed by pharyngeal slits in chordates?
Pharyngeal slits give rise to structures such as the Eustachian tube, middle ear cavity, tonsils, and parathyroid glands. In aquatic chordates, they form internal gills.
What is the function of the endostyle in chordates?
The endostyle secretes mucus to trap food particles in the pharyngeal cavity, serving as an efficient filter feeding apparatus and precursor to the thyroid gland in lamprey and vertebrates.
What structures trap food inside the pharynx of amphioxus?
Sheets of mucus
Where do the mucus nets converge in amphioxus?
On the dorsal side
How is the mucus in amphioxus rolled into a cord and passed posterior to the esophagus?
Converging mucus nets roll the mucus into a cord
Where do amphioxus live?
In sandy bottoms of coastal waters around the world
How long are amphioxus typically?
About 5-7 cm long
How many species of amphioxus are described?
25 species
What is the head of amphioxus described as in adults?
Having all hallmarks of Subphylum Cephalochordates (Lancelets, Branchiostoma, Amphioxus)
What are some structural features of amphioxus that resemble the vertebrate plan?
Hepatic cecum resembling the vertebrate pancreas, digestive enzymes and hormones, segmented trunk musculature, myomeres arranged in chevrons, dorsal and ventral aorta, and branchial aortic arches
What are the two embryonic innovations that led to the development of the vertebrate head and special sense organs?
Neural crest and ectodermal placodes
What are neural crest cells and where do they move during early development?
Neural crest cells are cells that leave the nerve cord and move through the body to form important nerves, neural ganglia, and head and facial features
What are ectodermal placodes and what do they form?
Ectodermal placodes are platelike ectodermal thickenings that form sensory organs or receptors and are anatomically distinct from neural crest cells
What are the characteristics of Subphylum Vertebrata in terms of Hox Genes?
Vertebrates have four clusters of Hox genes on four separate chromosomes, which have arisen by two genome duplication events.
What role do Hox Genes play in vertebrates?
They may play a key role in the evolutionary diversity that characterizes vertebrates, and gene duplication could be the primary mechanism for the evolution of complexity in higher organisms.
What are the chief diagnostic features of chordates according to Subphylum Vertebrata characteristics?
Notochord, dorsal tubular nerve cord, pharyngeal pouches, endostyle or thyroid gland, and postanal tail are all present at some stage of the life cycle.
Describe the characteristics of the vertebrate endoskeleton.
It consists of a vertebral column and a cranium.
What is the structure of the vertebrate circulatory system?
It consists of a multichambered ventral heart, closed blood vessel system, paired aortic arches, and blood containing erythrocytes with hemoglobin.
What is the excretory system of vertebrates like?
It consists of paired glomerular kidneys provided with ducts to drain waste to the cloaca.
What is the integument of vertebrates composed of?
It has two divisions - an outer epidermis of stratified epithelium and an inner dermis of connective tissue, with many modifications such as skin glands, scales, feathers, claws, horns, and hair.
What embryonic innovations in vertebrates resulted in the development of the head and special sense organs?
NEURAL CREST and ECTODERMAL PLACODES are two vertebrate embryonic innovations that led to the vertebrate head and special sense organs, respectively.
What is the structure of the vertebrate brain like?
It is highly differentiated and consists of 10-12 pairs of cranial nerves, spinal nerves for each primitive myotome, and paired special sense organs derived from ectodermal placodes.
What is the reproductive system of most vertebrates like?
Most vertebrates have separate sexes, each containing gonads with ducts that discharge their products either into the cloaca or into special openings near the anus.
What are the 5 hallmarks of chordates?
Notochord, Dorsal nerve chord, Pharyngeal grooves/pouches/slits, Endostyle/Thyroid gland, Post-anal tail
Ecdysozoa Flashcards
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How many species may exist according to the text?
Million species may exist.
Where can nematode parasites be found?
Nematode parasites are found in nearly all animal and plant species.
What do freeliving nematodes feed on?
Freeliving nematodes feed on bacteria, yeasts, fungal hyphae, and algae.
What do predatory nematodes eat?
Predatory nematodes eat rotifers, tardigrades, small annelids, and other nematodes.
What is the importance of nematodes in the soil food web?
Nematodes are important as food for mites, insects, larvae, and nematode-eating fungi.
What is the function of the layers of crisscrossing collagen in nematodes?
Providing elasticity but restricting lateral expansion to allow for hydrostatic pressure when fluid is exerted from pseudocoelom.
What is the hydrostatic skeleton in nematodes composed of?
A non-compressible fluid enclosed and pressurized in a body cavity.
How do nematodes achieve movement through muscle contractions?
Longitudinal muscles contract in groups producing local shortening.
Why is the pseudocoelomic fluid in nematodes considered incompressible?
To allow for the internal pressure to increase and stretch muscle cells in different parts of the body.
How do the dorsal and ventral longitudinal musculature in nematodes act during locomotion?
They act as antagonists, producing sinusoidal waves along the length of the nematode's body.
What is the outer layer of roundworms called?
Cuticle
What is the noncellular outer layer of roundworms secreted by the underlying epidermis called?
Hypodermis
Where are the nuclei located in the hypodermis of roundworms?
In four hypodermal cords projecting inward
What are the longitudinal nerves associated with the dorsal and ventral hypodermal cords in roundworms?
Dorsal and ventral nerves
What do the lateral cords in roundworms contain?
Excretory canals
How many layers of crisscrossing collagen does the cuticle of roundworms have?
Three layers
What is the function of the collagen in the cuticle of roundworms?
Provides elasticity but restricts lateral expansion
What type of skeleton do roundworms have that is based on hydrostatic pressure?
Hydrostatic skeleton
What is the fluid enclosed and pressurized in the body cavity of roundworms called?
Pseudocoelomic fluid
How many fields of longitudinal muscles do roundworms have for locomotion?
Four fields
How do the longitudinal muscles of roundworms contract for locomotion?
They contract in groups producing local shortening
What happens to the muscle cells in roundworms when the internal pressure increases due to the incompressible pseudocoelomic fluid?
They stretch in another part of the body
What type of waves are produced along the length of a nematode's body during locomotion?
Sinusoidal waves
What acts as antagonists in the locomotion of nematodes by producing sinusoidal waves along the length of the body?
The dorsal and ventral longitudinal musculature
What are the economic importance categories of nematodes?
Medical (humans), companion animals, livestock, and crops
What is a characteristic of nematodes regarding their migrations within vertebrate hosts?
Extensive migrations
Do parasitic nematodes attain greater sizes than non-parasitic ones?
Yes
What is a characteristic of nematodes regarding their reproductive capacities?
Enormous reproductive capacities
What are the two strategies used by nematode parasites?
Direct (single host) and Indirect (additional intermediate hosts)
Where are nematode eggs or larvae typically found?
In feces or urine
At what stage are the infective larvae of nematodes usually found?
L1 or L3 (third stage larvae)
What stage of larvae may be freeliving in the life cycle of nematodes?
L1 or L3
What is the stage of larvae that is infective in the general parasitic life cycle of nematodes?
L3
What are the stages of molting between in the nematode life cycle?
L1, L5
What is the immature adult stage in the nematode life cycle?
L5
What are the hosts involved in the generalized parasitic life cycle of nematodes?
Definitive host (DH) and Intermediate host (IH)
What is the stage in the nematode life cycle that is responsible for reproduction?
Yelproduction
What is the stage of nematodes that serves as the infectant stage?
L3
Are nematodes considered important for population control?
Yes
What can infections cause in children?
Anemia
What can occur when eggs are ingested with uncooked vegetables or when children put soiled fingers into their mouths?
Infection with parasitic nematodes like Ascaris and hookworms
How do parasitic nematodes like Ascaris enter the host's body and mature?
Host swallows embryonated eggs, juveniles hatch, burrow through intestinal wall to veins and lymph vessels, move through the heart and lungs, break into alveoli, carried up to trachea, swallowed at pharynx, mature in intestine after two months
What are the symptoms and consequences of heavy infections with hookworms?
Anemia, mental retardation, stunned growth, lack of energy due to the worms sucking more blood than they digest from the host's intestines
How do hookworms infect humans and mature in the intestine?
Eggs pass out in feces, juveniles hatch in soil, burrow through skin to blood vessels, travel in blood to lungs, coughed up, swallowed, mature in intestine
What is the role of free-living nematodes in the environment?
Free-living nematodes have a fundamentally important role in the environment as nutrient recyclers. They are decomposers who make nutrients available to other organisms.
What is the take-home message related to nematodes mentioned in the text?
Wash your hands before you eat, cook your food well, and avoid eating dirt. Drug treatments are available if you forget to follow these precautions.
What is the unique characteristic of nematodes' muscle arrangement mentioned in the text?
Nematodes only have longitudinal muscle antagonistic pairing.
What type of skeleton do nematodes have, as mentioned in the text?
Nematodes have a hydrostatic skeleton called pseudocoel.
How do parasites mentioned in the text migrate in the body?
Parasites mentioned in the text can migrate in the body through direct or indirect lifecycle.
Provide four examples of free-living nutrient cyclers as mentioned in the text.
Fungal, bacterial, N, P in the soil food web are examples of free-living nutrient cyclers.
What causes elephantiasis?
Inflammation and blockage of the lymphatic vessels
How do females of the parasite responsible for elephantiasis release their young?
They release live young, tiny microfilariae into the blood and lymph
What is the role of mosquitoes in the life cycle of the parasite causing elephantiasis?
Mosquitoes act as intermediate hosts by ingesting microfilariae when they feed on infected animals, which then develop to the infective stage and are transmitted to another host when the mosquito feeds again
What is the importance of free-living nematodes in the environment?
Free-living nematodes play a fundamentally important role in the environment as nutrient recyclers, decomposing organic matter and making nutrients available to other organisms
What is the take-home message regarding hygiene and prevention discussed in the text?
Wash your hands before you eat, cook your food well, and avoid eating dirt. Drug treatments are available if hygiene measures are not followed
What type of muscle arrangement do nematodes have?
Nematodes have only longitudinal muscle arrangement
What is the structure that nematodes use for support and movement?
Nematodes have a hydrostatic skeleton called a pseudocoel
How do parasites migrate in the body in terms of lifecycle?
Parasites can migrate in the body through direct or indirect lifecycles
Provide four examples of free-living nutrient cyclers mentioned in the text
Fungal, bacterial, nitrogen-fixing bacteria, and soil nematodes
Arthropoda 1 Flashcards
Study
How was the soft cuticle of arthropod ancestors stiffened?
Deposition
What are some characteristics of Arthropoda?
- Suit of Armor - Efficient gas exchange systems particularly in terrestrial forms - Highly developed sense organs - Complex behavior patterns - Metamorphosis resulting in less competition for resources
How many species of arthropods have been recorded to date?
Approximately 1,100,000 species
What is the range of sizes for arthropods?
Sizes range from the giant Japanese crab with a four-meter leg span to the small 0.1 mm long follicle mite, generally less than 60 cm in size.
What are some adaptations of arthropods for varied habitats and modes of feeding?
Arthropods have adaptations to live on land, in the sea, in the air, and as parasites. They have varied modes of feeding ranging from carnivory, herbivory, to omnivory.
What are some reasons for the success, abundance, and diversity of arthropods?
1) Exoskeleton for protection against desiccation, 2) Tagmatization for specific functions in different body regions, 3) Efficient gas exchange systems, 4) Highly developed sense organs, 5) Complex behavior patterns, 6) Metamorphosis reducing competition for resources.
What is chitin and how does it contribute to arthropod characteristics?
Chitin is a long-chain polymer of N-acetylglucosamine, a derivative of glucose. It stiffens the soft cuticle of arthropod ancestors, forming a hardened exoskeleton that offers protection, muscle attachment sites, and improves locomotion and flight.
How do arthropods typically grow in size?
Arthropods typically molt several times, with mass limits determining their final body size.
What is the exoskeleton of arthropods compared to?
The exoskeleton of arthropods is compared to a suit of armor, providing protection and support.
What type of muscles do arthropods have for attachment to their exoskeleton?
Arthropods have complex muscular systems with striated muscles for rapid actions and smooth muscles for visceral organs.
Do arthropods have cilia for movement?
Arthropods do not have cilia for movement.
What are some distinctive features of arthropods' anatomy?
Segmentation and appendages are distinctive features of arthropods' anatomy.
What is the process called that stabilizes and hardens the protein layers in the exoskeleton of insects and crustaceans?
Sclerotization tanning
What are the two layers of the procuticle in insects and crustaceans, and what are they made of?
Exocuticle secreted before a molt and endocuticle secreted after molting. They contain chitin bound with protein that is insoluble in water, mild acids, and alkalis.
What is the function of the procuticle in insects and crustaceans?
The procuticle is lightweight and flexible while providing protection against dehydration, biological, and physical stresses.
How does the composition of chitin in the procuticle vary between insects and crustaceans?
In insects, chitin makes up about 50% of the procuticle, while in crustaceans, it ranges from 60-80%. Some areas in crustaceans also have calcium salts for increased strength but reduced flexibility.
What are apodemes in crustaceans and insects, and what is their function?
Apodemes are ingrowths in the cuticle that serve as attachment points for muscles, similar to tendons. They support movement and also line the foregut, hindgut, tracheae, mouthparts, sensory organs, copulatory organs, and serve ornamental purposes.
What is ecdysis or molting, and what is its purpose in arthropods?
Ecdysis is the process of shedding the outer covering and growing a new, larger one. It allows arthropods to grow, as they typically molt several times, with body size limited by mass.
What are the characteristics of the muscular system in arthropods?
Arthropods have a complex muscular system with the exoskeleton for attachment. They have striated muscles for rapid actions and smooth muscles for visceral organs, lacking cilia.
Describe the pattern of segmentation and appendages in arthropods for efficient locomotion.
Arthropods have a primitive pattern of a linear series of similar segments with jointed appendages. Many segments may be fused into specialized groups called tagmata, with appendages differentiated and specialized for various functions like food sensing, handling, walking, or swimming.
What are the excretory organs called in some organisms with maxillary glands?
Malpighian tubules
What is the respiratory system like in these organisms?
Similar to that of annelids
How is the nervous system structured in these organisms?
Similar to annelids with a dorsal brain connected by a ring around the gullet to a double nerve chain of ventral ganglion fusion of ganglion in some species
Are the sensory organs well-developed in these organisms?
Yes, they have highly developed sensory organs
How do the behavioral patterns of these organisms compare to other invertebrates?
Behavioral patterns are much more complex with wider occurrence of social organization like bees and ants
What are some of the sensory structures in these organisms?
Eyes (vary from simple light-sensitive ocelli to a compound mosaic eye), touch, smell, hearing, balancing, and chemical reception
What are arthropods?
Arthropods are ecdysozoan protostomes in the clade Panarthropoda.
How are groupings among arthropod subphyla now based on?
Groupings among subphyla are now based on molecular data, which conflicts with traditional classifications.
What is the subphylum that insects belong to according to molecular evidence?
Insects are now classified under the subphylum Hexapoda, while others are under the subphylum Myriapoda within the group Uniramia.
What is the Mandibulate hypothesis in arthropod classification?
The Mandibulate hypothesis suggests that myriapods, hexapods, and crustaceans are more closely related due to a shared mouthpart, the mandible, forming the clade Mandibulata.
What is the alternative grouping in arthropod classification for organisms without mandibles?
Arthropods without mandibles form the group Chelicerates, supported by molecular evidence.
Crustacean Flashcards
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What are the two main types of limbs found in crustaceans?
Exopod and Endopod
Why do we like to eat crustaceans?
Because their bodies have a major portion of striated muscles
How are muscles arranged in crustaceans?
Most muscles are arranged as antagonistic groups with flexors drawing limb toward the body and extensors straightening a limb out
What do the abdominal flexors of a crayfish allow it to do?
Swim backward to escape predators with a strong burst of speed
What is a significant component of the crustacean body in terms of muscles?
Striated muscles
What are the basic parts of a crustacean appendage?
Basis, coxa, lateral exopod, medial endopod, exite, gill, epipod
What is the variation in the basic plan of crustacean appendages?
Walking legs become secondarily uniramous, Malacostraca and Remipedia have paired appendages on the abdomen (swimmerets) while other classes typically do not
What is serial homology in crustaceans?
A condition where many biramous appendages are homologous to each other but may have been modified to have different functions
How has structural evolution altered the ancestral limbs of crustaceans?
Ancestral limbs were all similar, but structural evolution has altered many parts with some lost, many gained, and others changed
What are the characteristics of the crustacean muscular system?
Striated muscles make up a major portion of the crustacean body. Most muscles are arranged as antagonistic groups, with flexors drawing the limb toward the body and extensors straightening a limb out. Abdominal flexors of a crayfish allow it to swim backward to escape predators with a strong burst of speed
What is the chief propulsive organ for the hemolymph in crustaceans?
Single-chambered sac of striated muscle
Where is hemolymph pumped from for oxygen and carbon dioxide exchange in crustaceans?
Afferent sternal sinus to the gills
What is the function of valves in the arteries of crustaceans?
Prevent backflow of hemolymph to the sinuses
What is the role of small arteries in crustaceans' circulatory system?
Empty into tissue sinuses which discharge into the large sternal sinus
How do crustaceans regulate the ionic and osmotic composition of body fluids?
Mainly through excretion of salts and amino acids
What do predators consume in the water?
Predators consume larvae, worms, crustaceans, snails, and fishes.
What do scavengers eat in the water?
Scavengers eat dead animal and plant matter.
What are some interesting adaptations for killing prey?
Interesting adaptations for killing prey include specialized feeding structures and hunting behaviors.
What is the Class of the crustacean group that includes mussel shrimp or seed shrimp?
The crustacean group is Class Ostracoda.
How many known species of mussel shrimp or seed shrimp are there worldwide?
There are 6000 known species of mussel shrimp or seed shrimp worldwide.
How long is the bivalve carapace that encloses most Ostracoda species?
The bivalve carapace ranges from 0.25 to 80 mm long.
How do most Ostracoda species feed and move?
Feeding and locomotion in most Ostracoda species are mostly done by head appendages.
Where are most Ostracoda species found in their habitat?
Most Ostracoda species are benthic or climb on plants, but some are planktonic and burrowing while others are parasitic.
How do Ostracoda species develop?
Ostracoda species develop by gradual metamorphosis.
What is ecdysis?
Ecdysis is the process of shedding the outer layer of skin or exoskeleton in arthropods and other invertebrates.
What is ecdysone used for in the ecdysis process?
Ecdysone is only needed to initiate ecdysis, which then proceeds on its own.
What are mandibles and maxillae used for in feeding habits?
Mandibles and maxillae are used for ingestion, while maxillipeds hold and crush food.
How do suspension feeders feed on food sources like plankton, detritus, and bacteria?
Suspension feeders generate water currents to feed on plankton, detritus, and bacteria. They use setae on their legs to strain food from the water.
What do predators in the ecosystem consume?
Predators consume larvae, worms, crustaceans, snails, and fishes. They have interesting adaptations for killing prey.
What are scavengers in the ecosystem known for eating?
Scavengers eat dead animal and plant matter to decompose them.
What are some characteristics of the crustacean group Ostracoda?
Ostracoda, commonly called mussel shrimp or seed shrimp, have around 6000 known species found worldwide in both marine and fresh water habitats. They are important in aquatic food webs.
How do most Ostracoda species move and feed?
Most Ostracoda are benthic or climb on plants, but some are planktonic and burrowing, while others are parasitic. Feeding and locomotion are mostly done by head appendages.
How do most Ostracoda species develop?
Most Ostracoda species undergo development by gradual metamorphosis.
What is the largest and most diverse class of Crustacea with over 20,000 species?
Class Malacostraca
What is the only truly terrestrial crustacean order?
Order Isopoda
Describe the characteristics of isopods.
Dorsoventrally flattened, lack a carapace, have sessile compound eyes
How do some isopods live in depths of 2,100 meters?
Some grow to large sizes (more than 40 cm long)
What is the class of crustaceans that barnacles belong to?
Class Cirripedia
What is the largest and most diverse class of Crustacea with over 20,000 species?
Class Malacostraca
What are some characteristics of Isopoda, an order of Malacostraca crustaceans?
Dorsoventrally flattened, lack a carapace, have sessile compound eyes
What is unique about Isopoda crustaceans in terms of their habitat?
They are the only truly terrestrial crustaceans, but also have marine and freshwater forms
How do cyprid larvae of barnacles attach to substrate during metamorphosis?
Using their first antennae with adhesive glands
What is the order that includes approximately 18000 species of arthropods such as crayfishes, lobsters, crabs, and true shrimp?
Decapoda
What is the distinguishing feature of crabs in comparison to crayfish or lobsters?
Broader cephalothorax and reduced abdomen
What is the size range of arthropods in the Decapoda order, from the smallest to the largest?
From a few millimeters to the Japanese spider crab with a 4 m leg span
How many pairs of walking legs do arthropods in the Decapoda order have?
Two pairs
What is special about the first pair of walking legs in arthropods of the Decapoda order?
They form pincers or chelae
Arthropoda 2 Flashcards
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What is the Subphylum of organisms with claws, fangs, poison glands, or stingers but no antenna or mandibles?
Chelicerata
How many species are in Subphylum Chelicerata?
40,000
How are the cephalothorax and abdomen joined in organisms of Subphylum Chelicerata?
By a slender pedicel
What are the anterior appendages in Subphylum Chelicerata?
A pair of chelicerae with terminal fangs
What are the sensory functions of pedipalps in Subphylum Chelicerata?
Used by males to transfer sperm
What are the basal parts of pedipalps used for in Subphylum Chelicerata?
To handle food
How many pairs of walking legs do organisms in Subphylum Chelicerata have?
4
What do chelicerae do in organisms of Subphylum Chelicerata?
Seize prey, inject venom, and feed by injecting digestive juices into prey to liquefy
What is the feeding process of organisms in Subphylum Chelicerata after injecting digestive juices into prey?
Sucking up broth into its stomach
What is the Order of organisms that include spiders?
Araneae
What are living fossils called that include horseshoe crabs?
Xiphosurids
How many extant species of horseshoe crabs are there?
5
What covers the body of xiphosurids in front of a broad abdomen and a long telson tail?
Unsegmented shield or carapace
How many pairs of walking legs does the cephalothorax of xiphosurids have?
5
What are the respiratory organs of xiphosurids?
Book gills
What do xiphosurids use for swimming?
Opercula
In which subphylum do xiphosurids belong?
Chelicerata
How many species are there in the class Arachnida under subphylum Chelicerata?
More than 80,000
Where are arachnids more common?
Warm, dry regions
Which arachnids were the first to move on land?
Scorpions
What are the anterior appendages of arachnids used for?
Pair of chelicerae with terminal fangs
What are the pedipalps of arachnids used for?
Sensory functions and transferring sperm
How many pairs of walking legs do arachnids have?
4
What do chelicerae of arachnids do to prey?
Seize prey, inject venom, and feed by injecting digestive juices to liquefy prey
Which order do spiders belong to?
Araneae
Hexapoda Flashcards
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What are the characteristics of land beetles in terms of their appearance?
Thick and shielded
How are aquatic beetles described in comparison to land beetles?
Streamlined
What is the physical appearance of walking sticks that allows them to camouflage on branches?
Long and slender
Why are cockroaches flat in shape?
To live in crevices
Which insect has the broadest wings of all insects?
Butterflies
What is the scientific classification of insects with an exoskeleton composed of complex plates or sclerites connected by flexible hinge joints?
Subphylum Hexapoda Class Insecta
What provides rigidity to the exoskeleton of insects and allows for precise movement?
Scleroproteins
What is the importance of chitin in the composition of the insect's cuticle?
Chitin is an important component of the cuticle, although rigidity is mainly due to scleroproteins
How does the lightweight and waterproof exoskeleton of insects benefit them in comparison to crustaceans?
Allows for flight
What is the main material that provides waterproofing and lightweight properties to the insect's exoskeleton?
Scleroproteins
What type of joints connect the complex plates or sclerites in an insect's exoskeleton?
Flexible hinge joints
What allows muscles to attach to the sclerites in an insect's exoskeleton, enabling precise movement?
Flexible hinge joints
What allows for the flexibility and movement in an insect's exoskeleton?
Muscles attaching to the sclerites through flexible hinge joints
What is the overall term used to describe the external form and function of insects?
Insecta External Form and Function
What is the main difference in material composition between the exoskeleton of insects and crustaceans?
Rigidity of exoskeleton is due to scleroproteins in insects, not chitin as in crustaceans
What are the characteristics of Order Diptera?
True flies, lost wings, contracted muscles, tergal articulations
What muscle contraction provides force for the upstroke in Diptera flies?
Dorsoventral sternotergal muscle contraction
What muscle relaxation and contraction provides force for the downstroke in Diptera flies?
Dorsoventral sternotergal muscle relaxation and longitudinal muscle contraction
What are the characteristics of Order Odonta Orthoptera?
Dragonflies, locusts, indirect flight muscles, dorsoventral sternotergal indirect muscle contraction
What provides force for the upstroke in Odonta Orthoptera flies?
Dorsoventral sternotergal indirect muscle contraction
What provides force for the downstroke in Odonta Orthoptera flies?
Direct flight muscles attached to part of the wing itself
How many pairs of wings do most flying insects have?
Most flying insects have two pairs of wings.
What is unique about the wings of Diptera (true flies)?
Diptera (true flies) have only one pair of wings.
What are halteres and what is their function in flies?
Halteres are reduced wings that provide the fly with balance during flight.
Which insects are wingless?
Non-reproductive ants, termites, lice, and fleas are wingless.
What provides the force for the upstroke in the flight of true flies (Order Diptera)?
Dorsoventral sternotergal muscle contraction pulls the tergum towards the sternum, providing force for the upstroke.
What provides the force for the downstroke in the flight of true flies (Order Diptera)?
Dorsoventral sternotergal muscle relaxation and longitudinal muscle contraction arches the tergum, providing force for the downstroke.
What is the flight musculature like in dragonflies and locusts (Order Odonta, Orthoptera)?
They have direct flight muscles attached to part of the wing itself, providing direct force for the downstroke.
How does the dorsoventral sternotergal indirect muscle contraction provide force for the upstroke in the flight of dragonflies and locusts?
Dorsoventral sternotergal indirect muscle contraction provides force for the upstroke in the flight of dragonflies and locusts, as before.
What structures branch out from the trachea in insects for gas exchange?
Tracheoles
How do small insects transport gas for gas exchange?
By diffusion gradient
What creates a partial vacuum in the tracheal system of insects, drawing air in?
O2 consumption
How do large insects pump air through their tracheal system?
Muscular movements of the abdomen
What allows aquatic insects to hold an air bubble over the surface for gas exchange?
Secreted wax and hairs
In some larval insects, what structures may be present for gas exchange within a closed tracheal system?
Tracheal or rectal gills
What is the purpose of the sieve plate in the tracheal system?
To prevent the entry of water and other substances
How do small insects perform gas transport in their tracheal system?
Entirely by diffusion gradient
What creates a partial vacuum in the tracheal system of insects, drawing air in?
Oxygen consumption
How do large insects pump air through their tracheal system?
Muscular movements of the abdomen
How do aquatic insects ensure gas exchange since their spiracles are usually non-functional?
They can hold an air bubble over the surface using secreted wax and hairs
What may be present in some larval insects as a method of gas exchange in a closed tracheal system?
Tracheal or rectal gills
Where does digestion but no absorption occur in insects?
Crop as salivary enzymes mix with food
What is the primary site of digestion and absorption in insects?
Midgut
What is the function of the ceca in insects?
Increasing the digestive and absorptive area
Where does water absorption primarily occur in insects?
Hindgut
What are the modes of feeding in insects?
Herbivorous, phytophagous, saprophagous, predaceous, parasitic, hyperparasitic, parasitoids
What is the role of Malpighian tubules and rectal glands in insects and spiders?
Excretion and water balance
What is the predominant nitrogenous waste product in insects and spiders?
Uric acid (HUr)
What ion exchange process occurs in Malpighian tubules to bring water in via osmosis in insects?
Proton pump adding hydrogen ions and exchanging for potassium ions
What is the function of specialized rectal glands in insects and spiders?
Reabsorb chloride, sodium, potassium, and water from urine draining into the intestines
Why is recycling of water important for insects living in arid environments?
Water retention for life in arid environments
What similarities does the insect nervous system share with larger crustaceans?
Fusion of ganglia, some species have a giant fiber system
What is the function of the stomadeal nervous system in insects?
Similar to the autonomic system of vertebrates
What do neurosecretory cells in the insect brain control?
Molting and metamorphosis
Where are most insect sense organs located?
Microscopic and in the body wall
What types of stimuli can insects respond to with their keen sensory perception?
Mechanical, auditory, chemical, visual, and other stimuli
What are the two types of eyes found in insects?
Simple ocelli and compound eyes
How many ommatidia may compound eyes in insects contain?
Thousands
What is the visual quality of the image seen by insects with compound eyes?
Myopic and fuzzy
What is the flicker fusion rate of flying insects?
200-300 flashes per second
What is the purpose of the convex surface of compound eyes in insects?
To give a wide visual field, up to 200 degrees
What is the main advantage of compound eyes in detecting motion?
Excellent at detecting motion
What are compound eyes composed of in insects?
Multiple photoreceptor units or ommatidia
What type of light can compound eyes in insects analyze?
Polarized and UV light
What is the function of the zone of UV absorbance in compound eyes of insects?
Acts as a nectar guide
What is the relationship between compound eyes in insects and plants?
Mutualistic co-evolution
What type of light can compound eyes in insects see along with white light?
UV light
What is the term for each stage between molts in insects?
Instar
In which stage do insects develop wings?
Last stage
What is the term for insects that do not undergo metamorphosis?
Ametabolous
What is the term for insects that undergo incomplete metamorphosis?
Hemimetabolous
What is the term for insects that undergo complete metamorphosis?
Holometabolous
What is the term for insects like silverfish and springtails whose young are similar to adults except in size and sexual maturation?
Ametabolous
What is the term for insects like grasshoppers, cicadas, mantids, true bugs, mayflies, and dragonflies that undergo gradual metamorphosis?
Hemimetabolous
What are the young of grasshoppers, cicadas, mantids, true bugs, mayflies, and dragonflies called?
Nymphs
What do bud-like growths in early instars of insects show?
Where the adult wings will develop
What are the stages in the metamorphosis process of insects that undergo gradual metamorphosis?
Egg, nymph, several instars, adult
What are some examples of highly organized social groups in the text?
Bees, Ants, Termites
What are some benefits of insects for human welfare mentioned in the text?
Insects produce honey, beeswax, silk, and shellac. Bees also pollinate $10 billion worth of food crops in the US annually.
What is the relationship between pollinating insects and flowering plants mentioned in the text?
Pollinating insects and flowering plants are tightly co-evolved.
What role do predaceous and parasitoid insects play in the ecosystem according to the text?
Predaceous and parasitoid insects are vital in controlling many pest insect populations.
How are dead animals consumed in the ecosystem according to the text?
Dead animals are rapidly consumed by fly maggots.
What is the role of insects in food chains according to the text?
Insects are critical components of most food chains and a central food source for many fish and birds.
What is dormancy and why do organisms enter dormancy?
Dormancy is a state of reduced activity or suspended animation in anticipation of deleterious environmental conditions. Organisms enter dormancy to survive harsh conditions such as extreme temperatures or lack of resources.
What are the different types of eyes found in insects?
Insects have visual compound eyes and simple non-image-forming eyes called ocelli, which are used for light production as seen in fireflies.
Where are tactile sensilla heavily concentrated in insects?
Tactile sensilla are heavily concentrated on the antennae, mouthparts, and legs of insects.
How do insects communicate through chemical means?
Insects communicate chemically through the use of pheromones, which can be used to mark trails or territories, establish social status, signal alarm responses, and recognize kin or colony members.
What is the role of auditory communication in insects?
Auditory communication is notable in insects such as crickets, grasshoppers, and cicadas, where sound production is used to attract mates, signal aggression, and facilitate aggregation of individuals.
What are some examples of highly organized social insect communities?
Some examples of highly organized social insect communities include bees, ants, and termites, which exhibit caste differentiation and rely on chemical and tactile communication.
How do insects benefit human welfare?
Insects benefit human welfare by producing honey, beeswax, silk, and shellac. They also play a crucial role in pollination, control pest populations, and serve as food for many fish and birds.
What are the potential impacts of a population of 2-40-60 million individuals per km^2?
Desimate crops, cause famine
What percentage of the global population is impacted at the peak of insect control measures?
10%
What are some drawbacks of using broad-spectrum insecticides for insect control?
Damage beneficial insect populations, persist in the environment, accumulate, insects develop resistance
What is Bacillus thuringiensis (Bt toxin) used for in insect control?
Biological control as a bacterial toxin
What are some alternatives to broad-spectrum insecticides for insect control?
Viruses, fungi, natural predators, parasites
What is integrated pest management?
The combined use of all practical techniques for pest control
What is the controversial practice involving the genetic modification of crops for insect resistance?
Genetic manipulation of crop species
Echinoderm and Hemichordate Flashcards
Study
What are dermal branchiae?
Projections of the coelomic cavity covered with epidermis and lined with peritoneum.
How does gas exchange occur in starfish?
Across podia and dermal branchiae papulae.
Describe the ciliary action in starfish for moving fluids.
Moves fluids in the opposite direction countercurrent.
What are the external features of a starfish?
Central disc with tapering arms, flattened and flexible body with pigmented and ciliated epidermis, mouth on the oral surface, ambulacrum running from mouth to arm tips, usually 5 arms, ambulacral groove bordered by rows of tube feet.
What class does a starfish belong to?
Asteroidea.
What prevents the loss of hydrostatic pressure in the water vascular system of sea stars?
One-way valve between lateral canal and foot
What is the structure of the feeding and digestive system in sea stars?
Mouth leading to short esophagus and large central stomach, lower cardiac part of stomach can be everted during feeding, upper stomach is smaller and connected to pyloric cecae in each arm, short intestine leads to intestinal cecae and anus
What type of feeders are most sea stars?
Carnivorous
What is the class of sea cucumbers?
Holothuroidea
What is the chief gas exchange organ of holothuroids?
Respiratory Tree
Where are the ambulacral regions with tube feet often restricted to?
Ventral surface sole
Where is the closed madreporite located in sea cucumbers?
Internal
What is the water vascular system in sea cucumbers filled with?
Coelomic fluid
Where are the ossicles embedded within in sea cucumbers?
Test
What are the tentacles of sea cucumbers called?
Buccal podia
What are the oral and aboral surfaces of sea cucumbers covered with?
Tentacles
What are the cloacal muscles responsible for in sea cucumbers?
Contracting cloacal dilation
How does water enter the respiratory tree of sea cucumbers?
Through the anus
What happens when the anal sphincter closes in sea cucumbers during gas exchange?
Cloaca contracts
What is the purpose of several short inhalations in sea cucumbers during gas exchange?
To fill the respiratory tree
How is the respiratory tree of sea cucumbers emptied during gas exchange?
One long exhalation with contraction of the tree
What are Cuverian threads involved in for sea cucumbers?
Excretion
What is the respiratory system of acorn worms called?
Metanephridium
How do acorn worms connect their pharynx with the outside environment?
Through gill slits
What is the circulatory system of acorn worms composed of?
Dorsal and ventral vessels and a dorsal heart
What is the larval form of acorn worms called?
Tornaria larvae
Are the sexes of acorn worms separate or hermaphroditic?
Separate
How is fertilization carried out in acorn worms?
Externally
What is a unique larval development process observed in some acorn worm species?
Development of a ciliated tornaria larva similar to that of echinoderm larvae
What class do acorn worms belong to?
Enteropneusta
Describe the mucus-covered body of acorn worms.
The body of acorn worms is covered in mucus
What are the three distinct regions of an acorn worm's body?
Proboscis, collar, and trunk
How does the proboscis of an acorn worm function?
It probes the surroundings and collects food on its surface
How are particles carried to the mouth of an acorn worm?
Cilia carry particles to the mouth in the current direction as indicated by arrows
What happens when the body musculature of an acorn worm contracts?
Excess water is forced out through the gill slits
Do acorn worms undergo asexual reproduction?
At least one species of acorn worms undergo asexual reproduction
What is the basic plan similar to that of Enteropneusta?
Small animals usually 1 to 7 mm in length, many individuals may live together in collagenous tubes, zooids are not connected, body divided into three regions (proboscis, collar, and trunk)
What class do organisms with ciliated grooves on tentacles and arms that collect food belong to?
Class Pterobranchia
Are species in Class Pterobranchia dioecious, monoecious, or both?
Both dioecious and monoecious
How do organisms in Class Pterobranchia reproduce asexually?
By budding
Chordate Flashcards
Study
What structures do pouches in the ectoderm give rise to in amniotes?
Eustachian tube, middle ear cavity, tonsils, parathyroid glands
What structures do pouches in the endodermal lining of the pharynx give rise to in amniotes?
Eustachian tube, middle ear cavity, tonsils, parathyroid glands
What structures do pouches in aquatic chordates form?
Internal gills
What are the chordate hallmarks related to the Endostyle and Thyroid Gland?
1. Endostyle recently acknowledged as a chordate hallmark 2. Secretes mucus that traps food particles in pharyngeal cavity for efficient filter feeding apparatus
What is the first part of the endoskeleton to appear in the embryo?
Primitive chordates
What remains throughout life in primitive chordates and allows for undulatory body movement?
Axis for muscle attachment
What structure is always dorsal to the GI tract and initially tubular and hollow in most invertebrate phyla?
Dorsal nerve cord
In most chordates, what is the anterior end of the dorsal nerve cord enlarged to form?
Brain
In vertebrates, what does the nerve cord pass through for protection?
Neural arches of the vertebrae
What encloses the brain in vertebrates, providing protection?
Protective bony or cartilaginous cranium
What are pharyngeal slits openings that lead from the pharyngeal cavity to the outside formed by?
Pharyngeal grooves and pouches
In amniotes, which structures arise from the pharyngeal pouches?
Eustachian tube, middle ear cavity, tonsils, parathyroid glands
What is the function of the endostyle in chordates?
Secretes mucus that traps food particles in the pharyngeal cavity for efficient filter feeding
What do some cells within the endostyle secrete, which are iodine-rich proteins?
Iodine-rich proteins
What is the precursor of the thyroid gland in lamprey and vertebrates?
Endostyle
Where do pharyngeal grooves pocket in the ectoderm?
In pocketing of the ectoderm
Where do pharyngeal pouches outpocket in the endodermal lining of the pharynx?
Outpocketing of the endodermal lining of the pharynx
In which animals do internal gills form in aquatic chordates?
Aquatic chordates
In which animals do endostyles occur among all chordates but not in any other animals?
All chordates
What are the two continuous sheets that secrete mucous around the inside of the pharynx in cephalochordates?
Mucus nets
Where do the mucus nets converge in cephalochordates?
Dorsal side
What happens to the mucus when it is converged on the dorsal side in cephalochordates?
Rolled into a cord and passed posterior to the esophagus
What is another name for cephalochordates?
Lancelets
What is another term for Amphioxus in cephalochordates?
Branchiostoma
How do lancelets or amphioxus appear physically?
Slender, laterally flattened, translucent animals about 5-7 cm long
Where do lancelets or amphioxus live?
In sandy bottoms of coastal waters around the world
How many species of amphioxus are described?
25
What structural features in amphioxus resemble those of vertebrates?
Hepatic cecum, digestive enzymes and hormones, segmented trunk musculature (myomeres), dorsal and ventral aorta, branchial aortic arches
What is the purpose of a chambered heart in vertebrates?
To pump blood around the body.
What is the function of erythrocytes in vertebrates?
To contain hemoglobin for oxygen transport.
What are some characteristics of Subphylum Vertebrata?
Muscular gut with accessory digestive glands, paired glomerular kidneys, efficient for excretion of wastes, sensory system modifications for active predatory lifestyles.
What modifications are required for vertebrates with active predatory lifestyles?
New sensory, motor, and integrative control mechanisms for locating and capturing food.
What are the components of the tripartite brain in vertebrates?
Forebrain, midbrain, and hindbrain.
What sense organs are designed for distance reception in vertebrates?
1. Sophisticated Eyes 2. Pressure receptors in inner ears for equilibrium and sound 3. Chemical Receptors in olfactory organs 4. Lateral line Receptors for vibrations in water 5. Electrical Receptors in ampullary organs.
What is the capital city of France?
Paris
What is the largest planet in our solar system?
Jupiter
Who wrote the novel 'Pride and Prejudice'?
Jane Austen
What is the chemical symbol for gold?
Au
What is the world's longest river?
Nile
Who painted the Mona Lisa?
Leonardo da Vinci
What is the tallest mountain in the world?
Mount Everest
In which country is the Great Barrier Reef located?
Australia
What is the largest mammal on Earth?
Blue whale
Who is known as the 'Father of Computers'?
Charles Babbage
What are Ectodermal Placodes?
Plate-like ectodermal thickenings that appear on either side of the neural tube, anatomically distinct from neural crest cells, found only in vertebrates, and form sensory organs or receptors.
What are Hox Genes in vertebrates?
They are a group of related genes that control the body plan of the embryo along the anterior-posterior (head-tail) axis. Vertebrates have four clusters of Hox genes on four separate chromosomes, arising from two genome duplication events.
What are the chief diagnostic features of chordates?
Notochord, dorsal tubular nerve cord, pharyngeal pouches, endostyle or thyroid gland, and post-anal tail, all present at some stage of the life cycle.
What are the characteristics of vertebrates in terms of their body plan?
Endoskeleton consisting of a vertebral column and cranium, complex muscularized digestive tract with liver and pancreas, closed circulatory system with a multichambered ventral heart, excretory system with paired glomerular kidneys, tripartite brain, and neural crest and ectodermal placodes for head and sensory organs.
What are the two vertebrate embryonic innovations that resulted in the vertebrate head and special sense organs respectively?
Neural crest cells and ectodermal placodes.
What is the significance of gene duplication in vertebrates and higher organisms?
Gene duplication could be the primary mechanism for the evolution of complexity in higher organisms, leading to the diversity that characterizes vertebrates.
What are the characteristics of the integument in vertebrates?
It consists of two divisions: an outer epidermis of stratified epithelium and an inner dermis of connective tissue, with many modifications such as skin glands, scales, feathers, claws, horns, and hair.
What is the unique feature of the vertebrate skeleton?
It has a distinctive cartilage or bone endoskeleton consisting of a vertebral column, head skeleton (cranium), and pharyngeal skeleton derived largely from neural crest cells.
What are the specialized features of the muscular pharynx in fishes and tetrapods?
In fishes, the pharynx has pharyngeal pouches that open to the outside as slits and bear gills. In tetrapods, pharyngeal pouches are sources of several glands.
What is a key characteristic of the system in vertebrates consisting of paired glomerular kidneys provided with ducts to drain waste to the cloaca?
Paired glomerular kidneys provided with ducts to drain waste to the cloaca
What is a key characteristic of the brain in vertebrates of Subphylum Vertebrata?
Highly differentiated tripartite brain
How many pairs of cranial nerves are found in vertebrates of Subphylum Vertebrata?
12 pairs of cranial nerves
What are the special sense organs in vertebrates of Subphylum Vertebrata derived from?