Embryonic Development

Question 1

Parthenogenesis

Answer 1

Development is initiated by the egg without fertilisation

Question 2

Mus musculus

Answer 2

mouse

Question 3

Gallus gallus

Answer 3

chick

Question 4

Danio rerio

Answer 4

Zebrafish

Question 5

Caenorhabditis elegans

Answer 5

nematode

Question 6

Tribolium castaneum

Answer 6

red flour beetle

Question 7

Bombyx mori

Answer 7

silk moth

Question 8

Hox genes

Answer 8

Anterior-posterior patterning

Question 9

Pax6

Answer 9

Eye develpment

Question 10

Chordin/BMP

Answer 10

Neural development

Question 11

Xenopus laevis

Answer 11

Clawed frog

Question 12

Isolecithal eggs

Answer 12

Small and have little yolk evenly disributed in cytoplasm

Question 13

Mesolecithal eggs

Answer 13

Large eggs with moderate to large amounts of yolk that is localised ot one half of egg

Question 14

Telolecithal eggs

Answer 14

Moderate to large amounts of yolk that fill cytoplasm except for small area near animal pole

Question 15

Centrolethical eggs

Answer 15

Yolk concentrated in centre with a peripheral layer of yolk free periplasm

Question 16

In amphibians animal hemisphere is

Answer 16

darkly pigmented

Question 17

In amphibians vegetal hempishere is

Answer 17

lightly pigmented

Question 18

Mid-piece in spermatozoa contains

Answer 18

The base of the flagellum

Question 19

Hydatidiform moles

Answer 19

Either diploid with only male chromosomes or triploid with two copies of male chromosomes and 1 copy of female chromosomes

Question 20

Egg is surrounded by a membrane known as

Answer 20

Zona pellucida

Question 21

Cortical reaction to fertilisastion

Answer 21

Prevents polyspermy by modifying ZP3 receptor

Question 22

Holoblastic cleavage

Answer 22

Isolecithal and some mesolethical eggs and involves complete cleavage of egg

Question 23

Trophoblast

Answer 23

Blastomere epithelium

Question 24

Blastocoel

Answer 24

Cavity in the centre of embryo

Question 25

Inner cell mass

Answer 25

Small population of non-trophoblast cells found at one end of the blastocoel

Question 26

Morula

Answer 26

After 5th horizontal cleavage 4 tiers of 8 cells

Question 27

Blastula

Answer 27

When cleavage becomes more variable

Question 28

Meroblastic cleavage

Answer 28

Telolecithal and centrolecithal eggs with large amounts of yolk where complete cleavage is difficult

Question 29

Discoidal cleavage

Answer 29

Only a small yolk free portion of egg is cleaved typically at animal pole

Question 30

Superficial cleavage

Answer 30

Male and female haploid nuclei fuse deep within yolky centre of egg where first 9 nuclear divisions occur

Question 31

Mid-blastula transition

Answer 31

The switch from cell divisions without gap phases to ones with gap phases

Question 32

Gap phases

Answer 32

allow genome to be transcribed and to replace maternal transcripts which are gradually destroyed

Question 33

Mesodermal cell types

Answer 33

Connective tissue, Muscle, Dermis + subcutaneous layer Skeleton, kidneys, adrenal cortex

Question 34

Endodermal cell types

Answer 34

G.I. tract, liver, pancreas, endocrine glands, auditory system, urinary system

Question 35

Ectodermal cell types

Answer 35

Epidermis, nervous system, pigment cells

Question 36

Germinal vesicle

Answer 36

Describes eggs in animal hemisphere

Question 37

Nodal is a TF

Answer 37

required for mesoderm formation

Question 38

Vitellagen forms ____%

Answer 38

90% of xenopus egg

Question 39

Brachyury

Answer 39

Formed in mesoderm of all chordate embryos: early cell fate and regulate gastrulation

Question 40

Skeletal muscle expresses

Answer 40

Myosin II, Titin, MyoD1

Question 41

Smooth muscle expresses

Answer 41

BMP

Question 42

Neural plate folds _____ to form

Answer 42

Neural tube

Question 43

Primitive node -> _______ -> _________

Answer 43

Mesoderm, Neural plate

Question 44

Neural plate has ___________ epithelium

Answer 44

Pseudostratified columnar epithelium

Question 45

Mesoderm can be induced in an isolated cap by

Answer 45

Activin, Nodal , FGF4

Question 46

Insect eggs are held at ____ of meiosis

Answer 46

Metaphase I

Question 47

Mammalian eggs are held at ____ then ____ of meiosis

Answer 47

Prophase I then Methaphase II during ovulation

Question 48

Andromorphs

Answer 48

Only male chromosomes: abnormal growth of placental tissues and no discernable embryo

Question 49

Gynomorphs

Answer 49

Only female chromosomes : poorly developed placental tissue and poorly formed embryo

Question 50

Genetic Imprinting

Answer 50

DNA + associated histone proteins are officially modified during gametogenesis so associated genes are inactive during development

Question 51

Disorders associated with genetic imprinting

Answer 51

Angelman, Beckwith-Wiedenem, Prader-Willis, Silver-Risa

Question 52

Cell cycle length may be controlled by ratio

Answer 52

of DNA to cytoplasm