EMBRYOLOGY

Question 1

what is differentiation?

Answer 1

specialisation
change in appearance and structure
adoption of new functions

Question 2

what is cell arrangement?

Answer 2

physical and functional linkages

formation of tissues

Question 3

what is apoptosis?

Answer 3

programmed cell death in response to specific signals

Question 4

what is induction?

Answer 4

the ability of one cell type to cause another to differentiate

Question 5

what is cell migration?

Answer 5

movement from one location to another

Question 6

what causes angelman syndrome?

Answer 6

Deletion on maternal chromosome 15

Question 7

what causes prader willi syndrome?

Answer 7

Deletion on paternal chromosome 15

Question 8

what is cell division?

Answer 8

increase in the number of cells

Question 9

what are the six phases of embryogenesis?

Answer 9

gametogenesis
fertilisation 
cleavage 
gastrulation 
formation of a body plan 
organogenesis

Question 10

what causes trisomy 21?

Answer 10

additional copy of chromosome 21 caused by nondisjunction

Question 11

what is a zygote?

Answer 11

single cell embryo, diploid

Question 12

what is cleavage?

Answer 12

period of rapid cell division but with no increase in size

Question 13

how is a body plan formed?

Answer 13

embryonic folding

Question 14

what is organogenesis?

Answer 14

formation of organs and organ systems

Question 15

what occurs during the foetal period? (5)

Answer 15

growth and weight gain 
tissues mature and become functional 
overt sexual differentiation 
bone laid down 
connections made in CNS

Question 16

what are the primary processes for formation of an embryo? (6)

Answer 16

cell division 
differentiation 
cell attachment 
apoptosis 
induction 
cell migration

Question 17

what are the secondary processes in the formation of an embryo?

Answer 17

axis formation/polarity

folding/rotation

Question 18

what does meiosis cause in gametogenesis?

Answer 18

genetic variation

Question 19

how long does spermatogenesis take and when does it begin?

Answer 19

64 days

Question 20

what is oogenesis?

Answer 20

the formation of female gametes

Question 21

when is oogenesis arrested and restarted?

Answer 21

arrested in prophase at weeks 28-30

restarted in puberty

Question 22

what is nondisjunction?

Answer 22

chromosome doesn’t split and both are pulled to one side, meaning theres three copies when joined with the other gamete

Question 23

what is established at gastrulation and what happens if this goes wrong?

Answer 23

body axes are established

structures can be in the wrong place

Question 24

what is posterior called in an embryo?

Answer 24

dorsal

Question 25

what is anterior called in an embryo?

Answer 25

ventral

Question 26

what is superior called in an embryo?

Answer 26

cranial

Question 27

what is inferior called in an embryo?

Answer 27

caudal

Question 28

what is weeks 3-8 of development called?

Answer 28

embryonic period

Question 29

what is weeks 9-40 of development called?

Answer 29

foetal period

Question 30

what is fertilisation?

Answer 30

fusion of sperm and an oocyte

Question 31

what is formed by cleavage over days 1-4?

Answer 31

morula and then a blastocyst

Question 32

what is gastrulation?

Answer 32

formation of the germ layers at week 3

Question 33

when does an embryo have a large gain in height and weight?

Answer 33

``` height = 2nd trimester weight = 3rd trimester ```

Question 34

what is weeks 0-3 of development called?

Answer 34

conceptus/embryo

Question 35

what week is critical for birth defects?

Answer 35

5

Question 36

what is gametogenesis?

Answer 36

the formation of gametes

Question 37

what is a gamete?

Answer 37

a haploid sex cell (23 chromosomes)

Question 38

what stages make up gametogenesis?

Answer 38

mitosis and meiosis

Question 39

what is spermatogenesis?

Answer 39

the formation of male gametes

Question 40

what are the germ layers from outer to inner?

Answer 40

ectoderm mesoderm endoderm