Lecture 12 - Vertebrate Life History

Question 1

What impact on fertilisation did the move to land have for vertebrates?

Answer 1

Internal fertilisation, an amniotic egg, and direct development

Question 2

Are terrestrial vertebrates ecto or endothermic?

Answer 2

Most are endothermic, although reptiles are ectothermic.

Question 3

How do vertebrates protect their gametes?

Answer 3

By returning to water (amphibians) or internal insemination (amniote vertebrates)

Question 4

How do vertebrates protect their young?

Answer 4

Shelled yolky eggs, viviparity, postnatal parental care

Question 5

Are birds more related to reptiles or mammals?

Answer 5

Reptiles

Question 6

Allantois

Answer 6

Stores embryo waste

Question 7

Chroion

Answer 7

Blood vessels and gas exchange

Question 8

Amnion

Answer 8

Fluid-filled, protects embrio

Question 9

Vitellus

Answer 9

Yolk sac, nutrient store

Question 10

Layers of an amniotic egg

Answer 10

Calcareous shell, allantois, chorion, amnion, vitellus

Question 11

All birds are oviparous

Answer 11

True

Question 12

All reptiles are viviparous

Answer 12

False, some are oviparous

Question 13

All mammals are viviparous

Answer 13

False, monotremes lay eggs (and have no nipples)

Question 14

Asexual reproduction in vertebrates is

Answer 14

Rare - only some fish and reptiles

Question 15

Vertebrates with R strategy

Answer 15

Fish, amphibians

Question 16

Reptiles, birds, mammals have what reproductive strategy in common?

Answer 16

K strategy - high provisioning, parental investment, large eggs, larger body size, longer lifespan, sociality, overlapping generations, delayed maturity, parental care

Question 17

Iteroparity vs semelparity in vertebrates

Answer 17

Most vertebrates are iteroparous - some fish and antechinus are semelparous

Question 18

Which vertebrates use external fertilisation?

Answer 18

Aquatic vertebrates - fish and amphibians

Question 19

What type of fertilisation fo Agnathans use?

Answer 19

Ova & sperm released into coelom and then shed through genital pores

Question 20

Most vertebrates use what for fertilisation?

Answer 20

Ducts to carry ova and sperm

Question 21

Which birds have an intromittent organ?

Answer 21

Ratites, ducks & geese

Question 22

Squamate reptiles and tuatara have a

Answer 22

Hemipenes

Question 23

Mammals penis structure

Answer 23

Variable - sometimes bifid penes, sometimes bone support, sometimes blood-filled tissues

Question 24

Spermatophores

Answer 24

Sperm packets taken up by females - internal fertilisation

Question 25

Amphibian modes of fertilisation

Answer 25

Anurans - external
Caudata - internal, no intromittent organ
Gymnophiona - intromittent organ

Question 26

Sperm production

Answer 26

Related to testes size and structure, continuous or seasonal

Question 27

External vs internal fertilisation for sperm

Answer 27

External have more sperm and larger volume

Question 28

How long is sperm stored for?

Answer 28

Mammals - days to weeks
Birds - weeks to months
Reptiles - weeks to years

Question 29

Reproductive modes

Answer 29

Oviparity
Ovoviviparity
Viviparity

Question 30

Which tetrapods return to an aquatic enviornment?

Answer 30

Turtles, crocodiles, squamate reptiles, some birds, marine mammals

Question 31

Properties of water

Answer 31

1000x more dense
50x more viscous
3000x thermal capacity
sound travels 4-5x faster
impedes vision
30x less oxygen count
lower water loss

Question 32

Australian Long Necked Turtle

Answer 32

Has eggs which can survive inundation by water in muddy banks