Topic 2: Animal diversity pt 2

Question 1

did vertebrates start on land or water

Answer 1

water, Vertebrates inhabited the oceans for more than 150 million years before emerging on land

Question 2

what are the 3 major groups of vertebrates that have since transitioned back to living in the ocean?

Answer 2

Cetaceans (whales and dolphins)
Sirenians (manatees)
Pinnipeds (seals and walruses)

Question 3

all vertebrates are in chordata, so what 3 features do all vertebrates have?

Answer 3

bilateral symmetry, triploblastic, deuterostome development

Question 4

what 4 derived characteristics do all chordates have

Answer 4

notochord, dorsal hollow nerve cord, pharyngeal gill slits/clefts, muscular post-anal tail

Question 5

what are the groups of invertebrates within chordata

Answer 5

cephalochordata (lancelets), and urochordata (tunicates)

Question 6

what clade is the basal taxon of the chordates

Answer 6

cephalochordata

because moleculary they’re least like the rest of the chordates

Question 7

how do cephalochordata larvae feed vs adults

Answer 7

larvae feed on plankton by swimming upwards and passively sinking, adults bury themselves in the sand of the seafloor and become like suspension feeders.

Question 8

how do adult cephalochordata (lancelets) swim

Answer 8

by undulating side to side

Question 9

are urochordata molecularly more related to other chordates or lancelets

Answer 9

other chordates

Question 10

what do tunicates and all other vertebrate embryos have that lancelets don’t have. Also a diagnostic characteristic for vertebrates, describe it

Answer 10

a neural crest, which is a collection of cells along the edges of the closing neural tube in embryos. It gives rise to teeth, bones, cartilage in the skull, neurons, sensory capsules (for eyes etc)

Question 11

what are the sister taxa and living jawless vertebrates in the clade cyclostomes

Answer 11

Myxini (hagfishes) and Petromyzontida (lampreys)

Question 12

what taxa loses their chordate features after metamorphosis

Answer 12

Urochordata (tunicates), the chordate characteristics are more apparent in the larval stages than adult stages.

Question 13

describe hagfishes looks, how they swim

Answer 13

Highly reduced vertebrae and skull made of cartilage, notochord, small brain eyes ears and nasal opening, teeth made of keratin. swim in a snake-like fashion using muscle segments.

Question 14

describe lampreys looks, how they feed

Answer 14

parasites, larvae resemble lancelets, and are suspension feeders like lancelets.

Question 15

what’s are the 4 derived characters of gnathostomes (derived = developed after common ancestor, so hagfishes and lampreys don’t have)

Answer 15

jaws, duplication of hox gene sets, forebrain enlarged, and lateral line system (rows of sensory organs along the body)

Question 16

hagfish and lampreys lack…

Answer 16

jaws and backbones

Question 17

what 6 animal groups are included in the gnathostomes group

Answer 17

chondrichthyans (sharks, rays), ray-finned fishes, amphibians, reptiles, birds and mammals

Question 18

describe the body of a chondrichthyans (skeleton and shape)

Answer 18

their skeleton is cartilaginous, made from cells called chondrocytes. They have streamlined bodies and powerful muscles but can be clumsy.

Question 19

how do chondrichthyans (sharks, rays etc, within vertebrates) float?

Answer 19

they store oils in their liver to help them float, and continuous swimming, if they stop swimming they will sink.

Question 20

to allow gas exchange in chonrichthyans (sharks, rays) what must they do

Answer 20

swim continuously to allow gas exchange over their gills

Question 21

how do large vs small chondrichthyans feed (sharks, rays)

Answer 21

large sharks (whale shark think big guy from finding nemo with straw teeth) and rays are suspension feeders, and smaller sharks are carnivores (like small viscous dog)

Question 22

chondrichthyans reproduction (internal or external fertilization)

Answer 22

reproduction is variable, though fertilization is always internal

Question 23

whats the cloaca in the shark

Answer 23

a common chamber used by the digestive tract and excretory system. reproductive tracts also empty into here.

Question 24

describe the 3 types of reproduction (after fertilization): oviparous, oviviparous, and viviparous

Answer 24

oviparous: lay eggs outside the body (just egg), oviviparous retain fertilized eggs in the oviducts, offspring are birthed after they hatch (so egg + live birth), viviparous: young develop in uterus and obtain nutrients through a yolk sac placenta

Question 25

how do rays feed

Answer 25

they are bottom dwellers they eat molluscs and crustacean, their tails can contain venomous barbs

Question 26

what are the types of fish included in the osteichthyans clade, common and latin names)

Answer 26

ray finned fish (actinopterygii), and lobe finned fish (sarcopterygii)

Question 27

what are the derived characteristics of osteichthyans

Answer 27

ossified (bony) endoskeletons, swim bladders (to control buoyancy) derived from lungs,

Question 28

how do osteichthyans swim efficiently?

Answer 28

they have scales and secrete mucus to reduce drag while swimming.

Question 29

osteichthyans reproduction

Answer 29

reproduction is mostly oviparous with external fertilization

Question 30

how are ray fish important and how have humans affected their populations

Answer 30

economically important to humans because they are a big source of food, industrial harvesting has reduced fish populations

Question 31

3 main lineages of lobe-finned (sarcopterygii)

Answer 31

1. Coelacanths (actinistia) 2. Lungfishes (dipnoi) 3. evolved to become tetrapods

Question 32

what are derived characters of tetrapods

Answer 32

limbs with digits, head separated from body via neck, pelvic girdle fused to backbone (allows for independent movement of arms and legs), loss of gills, pharyngeal gill slits became ears, glands and etc.

Question 33

what is the origin of tetrapods

Answer 33

things got stuck in shallow pods and may have used fins to try to move to new water sources.

Question 34

where do amphibians live

Answer 34

on land and in water (toads are basically terrestrial frogs but still amphibians).

Question 35

list and describe the stages of the amphibian (frog) life cycle

Answer 35

1. The larval stage is the tadpole, aquatic, herbivorous with gills. no legs swims by undulating 2. metamorphosis leads to development of legs, lungs, eardrums, and a carnivorous adapted digestive system, gills disappear and lateral line system also disappears. 3. adults return to the water to mate

Question 36

what habitat do amphibians require, why?

Answer 36

moist/wet habitats to allow for gas exchange across their skin. Their eggs also have no shell so they must lay their eggs in water.

Question 37

describe amphibians reproduction

Answer 37

fertilization is external, male sperm fertilizes eggs the same time they are released.

Question 38

how did amniotes adapt from Tetrapods

Answer 38

their eggs adapted to be terrestrial (unlike frog eggs designed for water), an amniotic egg with 4 membranes

Question 39

what are the amniotic egg 4 membranes, list and describe

Answer 39

1. the amnion: encloses the amniotic fluid 2. the yolk sac: attached to the embryo, contain nutrients 3. the allantois: disposal sac for metabolic waste of embryo (this includes CO2, so also involved in gas exchange) 4. the chorion: outermost membrane for gas exchange.

Question 40

what animals are included in the reptiles

Answer 40

tuaturas, lizards, snakes, turtles, crocodilians and birds

Question 41

what are the derived characteristics of reptiles that amphibians don't have, whats the exception

Answer 41

scales composed of keratin, lay shelled eggs on land (not water), ectothermic: absorb external heat as main body heat source. exception: birds are endothermic (maintain body temp via internal metabolism)

Question 42

what characteristic do diapsids have (within amniotes)

Answer 42

pair of holes on each side of skull to help control jaw movement

Question 43

what animals are within archosaurs (amniotes)

Answer 43

crocodilians, pterosaurs, dinosaurs, birds. (birds are last known living dinos)

Question 44

what animals are in lepidosaurs (amniotes), what do they eat

Answer 44

tuataras, and squamates (snakes, lizards). they eat eggs, insects, small lizards

Question 45

turtles are diapsids, but what characteristic did they lose

Answer 45

holes in the skull

Question 46

what are the most modified animal of the archosaurs? whats different abt them

Answer 46

birds, lack urinary bladder, females only have 1 ovary, and gonad size reduced, hallow bones, feathers made of b-keratin, endothermic (all to be lighter for flying),

Question 47

what are the derived characteristics of mammals

Answer 47

mammary glands: produce milk, hair and insulating fat layers, kidneys: help to conserve water when removing wastes from body, larger brain, endothermic, differentiated teeth (adapted for various food sources)

Question 48

what are the 3 types of mammals

Answer 48

marsupials, monotremes, and eutherians

Question 49

contrast marsupials monotremes and eutherians in terms of how they bear young and nurse them (nipples or no)

Answer 49

marsupials have placenta and give birth to live young, have nipples to make milk. monotremes lay eggs but have hair and produce milk (no nipples tho), eutherians have placenta and longer pregnancies, have nipples to make milk.

Question 50

what features are unique to primates

Answer 50

hands and feet adapted for grasping: digits have flat nails rather than claws, ridges (fingerprints), -monkeys and apes have opposable thumbs (thumbs can move opposite to other fingers). large brain, forward facing eyes, can use tools.

Question 51

what characteristics are unique to humans

Answer 51

bipedal (stand on 2 feet), reduced jaw bones and jaw muscles (flat faces), reduced canine teeth, shorter digestive tract

Question 52

why was bipedalism adapted?

Answer 52

adaptation for walking in drier regions (to conserve energy and walk farther bc dry =less food (energy source) and 2 leg walking takes less energy than 4 legs so they could walk further with less food).

Question 53

evolution of humans was not linear true or false

Answer 53

true it was not linear, there were lots of different paths and versions of humans.