Drosophila

Question 1

What is developmental biology?

Answer 1

the study of how an egg turns into a full grown organism

Question 2

What are stem cells?

Answer 2

cells that are not specialized

Question 3

Where do stem cells come from?

Answer 3

embryos and fetuses

Question 4

What are the 3 different stages of the life cycle of a fly?

Answer 4

embryonic stage
larval stage
adult stage

Question 5

What is cleavage?

Answer 5

It is a series of mitotic divisions after fertilization, where a zygote becomes a blastula.

Question 6

What are blastomeres? What is it called when they form a cell layer?

Answer 6

Blastomeres are smaller cells of a zygote. If arranged to form a cell layer, it is called a blastoderm

Question 7

Describe cleavage in early fly development

Answer 7

1. the cell undergoes incomplete division, that is to say the nucleus will divide many times
2. the incomplete cleavage will create a syncytium, a single cell with many nuclei
3. nuclei will move to the periphery of the embryo to form a syncytial blastoderm, a superficial layer of nuclei surrounding the yolky cytoplasm
4. cell membrane develops and encloses the nuclei, individual cells form, cellular blastoderm form

Question 8

What is another word for incomplete cleavage?

Answer 8

meroblastic

Question 9

What is another word for complete cleavage?

Answer 9

holoblastic

Question 10

What are the different yolk distributions?

Answer 10

isolecithal
mesolecithal
telolecithal
centrolecithal

Question 11

What are the different anatomical axis?

Answer 11

Anterior-Posterior Axis (head-tail)
Dorsal-Ventral Axis
Left-Right Axis

Question 12

What happens after cleavage?

Answer 12

gastrulation

Question 13

Describe gastrulation in early fly development

Answer 13

1. cells in the blastula form three germ layers: ectoderm, mesoderm, endoderm
2. mesoderm invaginates and forms a ventral furrow
3. blastula becomes a gastrula