Animal development 1

Question 1

What 5 processes are needed for development?

Answer 1

Cell division (cleavage) 
Pattern formation (spatial organisation of cells)
Morphogenesis (changes in form)
Differentiation (cell specialisation)
Growth

Question 2

How do genes influence development?

Answer 2

Gene expression controls cell behaviour by determining which proteins are made by the cell
The pattern of gene expression gives cells identity and makes them behave differently

Question 3

What are the 5 key cell activities?

Answer 3

Cell-cell communication
Cell shape changes 
Cell movement 
Cell proliferation 
Cell death (apoptosis)

Question 4

What is the A/P axis?

Answer 4

The anterior/posterior axis (head/tail)

Question 5

What is the D/V axis?

Answer 5

The dorsal/ventral axis (upper/lower) (back/front)

Question 6

What does cranial refer to?

Answer 6

Cephalic/anterior (head)

Question 7

What does rostral refer to?

Answer 7

Towards the oral/nasal region

Question 8

What does caudal refer to?

Answer 8

Tail or tail like (posterior)

Question 9

What is the P/D axis?

Answer 9

The proximal/distal axis (near/far)

Question 10

What does medial refer to?

Answer 10

The middle

Question 11

What does lateral refer to?

Answer 11

To the side

Question 12

What does apical refer to?

Answer 12

At the apex, point, or tip

Question 13

What does basal refer to?

Answer 13

At the base

Question 14

What does the transverse (coronal) section refer to?

Answer 14

The cross-section

Question 15

What does the sagittal (longitudinal) section refer to?

Answer 15

The lengthways section

Question 16

What are the germ layers?

Answer 16

Endoderm
Mesoderm
Ectoderm

Question 17

Describe pattern formation

Answer 17

Cells become organised in time and space and acquire an identity about what they will become (positional info)
The early stages involve cells being allocated to different germ layers that will give rise to different types of tissue

Question 18

What does the endoderm form?

Answer 18

The gut, liver, and lungs

Question 19

What does the mesoderm form?

Answer 19

The skeleton, muscle, kidney, heart, and blood

Question 20

What does the ectoderm form?

Answer 20

The epidermis of the skin, and nervous system

Question 21

What is mosaic development?

Answer 21

Specific determinants in the zygote are distributed unequally to the daughter cells during cleavage
The fate of each cell is predetermined in the egg by the factors it receives internally during cleavage- the cell’s environments cannot influence it

Question 22

What is regulative development?

Answer 22

Depends on interactions between ‘parts’ of the developing embryo by cell communication
The cell’s environment can influence its developmental fate
The embryo is able to develop normally even when parts are removed or rearranged