Deuterostomes II: Amphibians to Mammals

Question 1

Tetrapods arise from

Answer 1

lobe-finned fishes in the Devonian

Question 2

There are many transitional
forms between ____ and ____ but the ____ is the most informative

Answer 2

lobe-finned fishes and tetrapods
Tiktaalik

Question 3

What is the synapomorphy of tetrapod phylogeny?

Answer 3

four limbs

Question 4

Early tetrapods gave rise to 2 lineages:

Answer 4

amphibians and amniotes

Question 5

The first amphibians arise from

Answer 5

early tetrapods *soon after tetrapods appear in the Devonian

Question 6

Amphibians “both ways of living” are _____ tetrapods

Answer 6

basal

Question 7

Amphibians are divers and include:

Answer 7

frogs, toads, salamanders

Question 8

Although most are terrestrial, amphibians need

Answer 8

to be near bodies of water

Question 9

Amphibians eggs and skin are

Answer 9

not resistant to dehydration

Question 10

Most amphibians have an aquatic _____ stage and then goes through _____ to get to adult stage.

Answer 10

larval stage which then goes through
metamorphosis to give rise to the adult stage

Question 11

What are amniotes synapomorphy?

Answer 11

1. amniotic egg
2. dehydration-resistant skin
3. water-conserving kidneys

Question 12

Amniotic egg which enclosed the ____ in membranes and protected them from _____. It freed tetrapods from _____.

Answer 12

embryo in membranes and protected them from dehydration
freed tetrapods from water

Question 13

Amniotes dehydration resistant skin made of ____

Answer 13

keratin

Question 14

Water-conserving kidneys of amniotes minimize

Answer 14

water loss from urination

Question 15

Amniotes give rise to 2 sister clades

Answer 15

Reptiles (includes birds) and Synapsids (give rise to mammals)

Question 16

Reptiles arose from _________ during the _________

Answer 16

early amniotes
Carboniferous

Question 17

When did dinosaurs arise?
When did dinosaurs dominate?

Answer 17

early Triassic
dominated the rest of the Mesozoic (Age of Dinosaurs)

Question 18

Dinosaurs diverged into 2 main lineages Saurischian (“lizard-hipped”) dinosaurs: sauropods (long-necked
dinosaurs) and_________
* Ornithischian (“bird-hipped”): most herbivorous dinosaurs

Answer 18

theropods (most carnivores)

Question 19

Birds are reptiles that arose from _______ during the ________.

Answer 19

feathered tetrapods; Jurassic period

Question 20

What is thought to be one of the earliest dinosaurs capable of flight

Answer 20

Archaeopteryx

Question 21

All non-avian dinosaur clades died off in the

Answer 21

Cretaceous extinction

Question 22

________ survived the _______ and have become a highly successful clade

Answer 22

Avian dinosaurs (birds) survived the Cretaceous extinction and have
become a highly successful clade

Question 23

What do mammals arise from?

Answer 23

Synapsids

Question 24

When did mammals arise?

Answer 24

~225 MYA in the Triassic

Question 25

When did mammals become prevalent?

Answer 25

Cenozoic Era

Question 26

What is the sister group to reptiles?

Answer 26

Synapsid clade

Question 27

What are the 3 synapomorphies that arose in synapsid MRCA?

Answer 27

1. enlarged skull 2. specialized teeth 3. single opening in the skill behind each orbit

Question 28

Synapomorohies the arose in mammalian MRCA are:

Answer 28

Hair - derived from scales. Mammary glands that secrete milk

Question 29

3 clades of ancestral mammal

Answer 29

monotremes, marsupials, eutherians

Question 30

Monotremes (first beasts)

Answer 30

lay eggs with yolk - no placenta

Question 31

Marsupials (next to beasts)

Answer 31

Embryos develop in uterus but primarily rely on yolk

Question 32

Placental mammals (true beasts)

Answer 32

Embryos develop a placenta that absorbs nutrients from the maternal blood supply

Question 33

Monotremes are diverse

Answer 33

platypus

Question 34

Do monotremes lay eggs?

Answer 34

Yes, embryos get their nutrients from the yolk in the egg

Question 35

Monotreme babies have a long

Answer 35

lactation period (milk is secreted from patches of fur)

Question 36

In marsupials, embryos develop in the mother's uterus, BUT

Answer 36

relies primarily on its own yolk for nutrients

Question 37

Female marsupials have a

Answer 37

rudimentary, underdeveloped placenta

Question 38

Marsupial babies are reared in a protective pouch called the

Answer 38

marsupium

Question 39

Female placental mammals possess a true placenta that is connected to the _________

Answer 39

maternal blood supply

Question 40

What is a powerful mammalian model system used to understand human diseases?

Answer 40

Mus musculus