Animal Reproduction (embryology)

Question 1

zygote formation

Answer 1

male sperm fertilizes female egg to form a zygote

Question 2

cleavage

Answer 2

• a series of mitotic cell divisions of the zygote
• cell division to form a multicellular embryo

Question 3

morula

Answer 3

• post fertilization development
• solid ball of cells formed after fertilization
• occurs after further cell division and rearrangement of existing cells

Question 4

blastula

Answer 4

• hollow structure
• consists of a large layer of cells around a hollow space
• hollow only in invertebrate with small amounts of yolk

Question 5

Gastrula

Answer 5

little gut stage
gastrula results in 2 events
- formation of the primitive gut(archenteron) or digestive cavity
- formation of the embryonic germ layers

Question 6

germs layers

Answer 6

ectoderm: outer layer, surface area of animal (skin)
endoderm: inner layer, wall of digestive tract
mesoderm: middle layer, lining of body cavity

Question 7

Diploblastic vs Triploblastic

Answer 7

diploblastic
- two germs layers, endo and ecto
- radial symmetry
triploblastic
- 3 germ layers
- bilateral symmetry

Question 8

Neurula

Answer 8

early vertebrate embryo