Week 3 - Evolution and Diversity of Vertebrates 2

Question 1

What are the 3 main amphibian parental strategies?

Answer 1

1. Lay aquatic eggs - develop into larvae
2. Lay terrestrial eggs - hatch into small adults
3. Viviparous (live young)

Question 2

Which fungi is lethal to amphibians ?

Answer 2

Chytrid fungi - warming climate has provided optimal conditions

Question 3

What are the major causes of the amphibian biodiversity crisis?

Answer 3

Habitat loss
Over exploitation
Climate change
Disease - Chytrid fungi

Question 4

What are amniotes (Lissamphibia) ?

Answer 4

They are a sister group to the amphibians
They lay eggs on dry land, have no larval stage, have shell-less eggs

Question 5

How many extra-embryonic layers does the amniotic egg have?

Answer 5

4

Question 6

What are the 4 extra-embryonic membranes of the amniotic egg?

Answer 6

1st = Amnion (a membrane fluid sac, surrounding the embryo - PROTECTION)

2nd = Chorion (Outer membrane that surrounds the embryo and yolk sac- GAS EXCHANGE)

3rd = Allantois (STORES WASTE)

4th = Yolk sac (provides embryo with NUTRIENTS)

Question 7

What are some disadvantages of shelled eggs?

Answer 7

Must have internal fertilisation
Air varies in heat more than water does
Requires more parental care
Expensive to produce

Question 8

What are the 3 early amniotes distinguished by the number of openings in their heads?

Answer 8

Anapsids
Synapsids
Diapsids

Question 9

How many openings do Anapsids, Synapsids and Diapsids have ?

Answer 9

Anapsids = none
Synapsids = 1
Diapsids = 2

Question 10

What animal is a chelonian ?

Answer 10

Turtle

Question 11

What is a turtles top and bottom shell called?

Answer 11

Top shell = carapace
Bottom shell = plastron

Question 12

Which 2 groups are living chelonians (turtles) divided into?

Answer 12

Hidden-neck turtle
Side-neck turtle

Question 13

What are the 2 living lineages of Diapsids ?

Answer 13

Lepidosaurs and Archosaurs

Question 14

What are Lepidosaurs and what are they split into?

Answer 14

The largest group of non-avian reptiles
Lizards (tuataras)
Snakes (squamates)

Question 15

What are the Archosaurs split into?

Answer 15

Crocodilians - Alligators, crocodiles and gharials

Birds

Question 16

Why do crocodilians have 2 stomachs?

Answer 16

1st = muscular to ground prey
2nd = acidic to digest bones

Question 17

Why do crocodilians swallow stones?

Answer 17

To act as a ballast and aid prey digestion

Question 18

What are the 4 orders of reptiles?

Answer 18

• Chelonia
• Squamata
• Tuataras
• Crocodillia

Question 19

What organ do reptiles use for respiration?

Answer 19

Lungs

Question 20

How are snake lungs adapted to their long, thin bodies?

Answer 20

Their left lung is reduced or absent

Question 21

How does respiratory ventilation occur in reptiles?

Answer 21

Through rib movement

Question 22

What do turtles use instead of ribs to ventilate muscles?

Answer 22

They use inspiratory muscles, pull viscera back, expanding lungs.
Expiratory muscles contract to force viscera against lung to expel air.

Question 23

Are reptiles ectotherms or endotherms and what does that mean?

Answer 23

Reptiles are ECTOTHERMS - meaning they rely on external sources to regulate their body temp

Question 24

Does ectothermy lead to low or high metabolic rate ?

Answer 24

Low

Question 25

Why are reptiles not found in cold environments?

Answer 25

Because they are ectotherms

Question 26

How do reptiles conserve water?

Answer 26

They excrete nitrogenous waste as uric acid to conserve water Their body surface is covered in horny scales acting as a barrier to water loss.

Question 27

Which type of reproductive method (ovi, vivi ect) is most likely in warmer climates?

Answer 27

Oviparity (egg laying)

Question 28

What is the advantage of have no legs?

Answer 28

Movement through small spaces Movement in trees (even body weight) Burrowing Coiling (for defence, thermoregulation and prey constriction)

Question 29

What are some different forms of locomotion in snakes ?

Answer 29

1. Lateral undulation - left to right movement 2. Sidewinding - modified lateral undulation 3. Concertina - latter half of body grips wall and anterior stretches 4. Rectilinear - No lateral movement, Belly scales are lifted and pulled forward before being placed down

Question 30

How are Gecko feet adapted for running on water?

Answer 30

Toes have rows of setae, each is tipped by a set of spatulae - adhesion between water and spatulae are linked to electrical intermolecular attractions. Geckos run by slapping and pushing the water

Question 31

What adaptations to crocodiles have to be good predators?

Answer 31

Dermal pressure receptors so can sense disturbances in surface water. Also have a 2ndary palate(shelf in roof of mouth) enabling prey to be held without water entering mouth

Question 32

How are snakes adapted to be good predators?

Answer 32

Snake tongue collects odour particles and transfers particles into olfactory chamber – to detect chemicals, sensitive to compounds with high molecular weight. *Snakes use nostrils (olfaction) for long-range, and Jacobson’s organ (vomerolfaction) for short-range sensing.

Question 33

How do snakes jaws extend around large prey?

Answer 33

They have elastic ligaments and no pectoral girdle

Question 34

How is venom helped predators deal with large prey?

Answer 34

Can cause paralysis Helps capture prey by immobilisation Helps digestion thorough protease enzymes Complex mixture of proteins produced by special oral glands (in a sense – modified saliva). Injected quickly, before withdraw to safetly

Question 35

What are the 2 key glands in snakes?

Answer 35

Venom gland = venom toxin generation Accessory gland = activates venom

Question 36

What are ways animals have adapted to avoid predators?

Answer 36

Caudal autonomy - voluntary self amputation of tail Wriggling Mimicing of venomous creatures camouflage

Question 37

How can colour be used to communicate?

Answer 37

Bright colours to attract mates