Introduction to vertebrates

Question 1

What two substances is bone made of?

Answer 1

Collagen and apatite.

Question 2

What structural benefits does collagen have?

Answer 2

It is elastic and able to withstand tension.

Question 3

What structural benefits does apatite have?

Answer 3

It is brittle and good under compression.

Question 4

Cartilage is softer than bone. What is its purpose in the body?

Answer 4

Shock absorption.

Question 5

Where is cartilage usually found?

Answer 5

At the end of limb bones in the joints.

Question 6

What is calcification?

Answer 6

The process of strengthening cartilage by the accumulation of calcium.

Question 7

What chemical compound is apatite made of?

Answer 7

Calcium phosphate.

Question 8

Most vertebrates have endoskeletons, made of endochondral bone. How is endochondral bone formed?

Answer 8

The skeleton is initially made of cartilage, which is replaced by osteocytes as development progresses.

Question 9

What does ectoderm form?

Answer 9

The epidermis and nervous system.

Question 10

What does mesoderm form?

Answer 10

Muscles, blood vessels and the skeletal elements.

Question 11

What does endoderm form?

Answer 11

The organs, for example the gut and respiratory system.

Question 12

What is formed when the outer mesoderm and ectoderm interact?

Answer 12

Dermal bone and teeth.

Question 13

Cells from the neural crest migrate during development to form which structures?

Answer 13

The pharangeal arches and jaws.

Question 14

What is meant by the appendicular skeleton?

Answer 14

The pectoral (forelimb) and pelvic (hind limb) girdles.

Question 15

What is meant by the cranium?

Answer 15

The skull and mandibles.

Question 16

What is meant by the axial skeleton?

Answer 16

The neck, trunk, sacral and tail vertebrae.

Question 17

Approximately how many species of vertebrate are there?

Answer 17

40-50,000.

Question 18

The vertebrates contain the amniotes. What are the 2 main features of amniotes that allowed them to colonise the land?

Answer 18

1. Impermeable skin

2. Amniotic egg

Question 19

What is the scapular?

Answer 19

The shoulder bone.

Question 20

What bone forms the shoulder joint?

Answer 20

Coracoid.

Question 21

What is the single upper-arm bone?

Answer 21

Humerus

Question 22

What is the outer forearm bone?

Answer 22

Ulna.

Question 23

What is the inner forearm bone?

Answer 23

Radius.

Question 24

What are the carpal elements?

Answer 24

Wrist bones.

Question 25

What are the metacarpals?

Answer 25

Hand bones.

Question 26

What are the phalanages?

Answer 26

Digits.

Question 27

Why are carpal and tarsal elements reduced/non-existent in animals like sauropod dinosaurs?

Answer 27

To increase stability.

Question 28

What 3 bones is the pelvic socket composed of?

Answer 28

1. Ilium
2. Ischium
3. Pubis

Question 29

What is the femur?

Answer 29

The single thigh bone.

Question 30

What is the fibia?

Answer 30

The calf bone.

Question 31

What is the tibia?

Answer 31

The shin bone.

Question 32

What are the tarsals and metatarsals?

Answer 32

The ankle and feet bones respectively.

Question 33

What is a sacrum and what is its purpose?

Answer 33

When the pelvic girdle fuses to the sacral vertebrae, provides stability and strength in terrestrial animals. The whole organism is propelled forwards during locomotion not just the pelvis.

Question 34

What is a plantigrade stance and what lifestyle does it fit?

Answer 34

Where the foot is placed flat on the ground, for stability.

Question 35

What is a digigrade stance and what lifestyle does it fit?

Answer 35

Where the animal stands on its digits - this lengthens the stride length for increased speed, used by predators like the carnivores.

Question 36

What is a unguligrade stance and what lifestyle does it fit?

Answer 36

Where the animal stands on its unguis (toenails). For the ultimate cursorial lifestyle, used by prey groups like the ungulates.

Question 37

Why is the fossil record often a poor representation of diversity? Give 3 main reasons.

Answer 37

It is not complete; specimens are lost/destroyed, some rock types are better preserving than others, sampling bias etc.

Question 38

In a vertebra, what is the centrum?

Answer 38

A flat, weight-baring structure.

Question 39

What are the neural spine and transverse processes on vertebrae for?

Answer 39

Muscle attachment.