Lecture 2

Question 1

Mesoderm undergoes differentiation when?

Answer 1

During Neurulation

Question 2

Paired somites form from what?

Answer 2

Epimere

Question 3

Segmentation of somites proceeds in what direction?

Answer 3

Anterior to posterior (head to tail)

Question 4

The stages of frog embryo development (in order) are:

Answer 4

Cleavage, Gastrulation, Neuralation& segmentation, and organogenesis

Question 5

Cleavage produces what?

Answer 5

A blastula

Question 6

Cells in the blastula are—

Answer 6

totipotent

Question 7

Characteristics of gastrulation:

Answer 7

1) formation of blastopore
2) Cell migration/movement
3) Cell differentiation

Question 8

At the end of gastrulation, the embryo is–

Answer 8

Triploblastic

Question 9

Gastrulation produces—

Answer 9

the three primary germ layers

1) Endoderm
2) Mesoderm
3) Ectoderm

Question 10

The Neural plate becomes what, and then what again?

Answer 10

The Neural fold, and then the Neurocoel

Question 11

Somites form either side of the —

Answer 11

Neural tube

Question 12

Throughout Organogenesis, what happens to the specificity of the cells?

Answer 12

They go from pluripotent gastrula cells to multipotent neurula cells, and finally become fully differentiated within each organ system

Question 13

If all somatic cells have the same genes, why don’t they all do the same thing?

Answer 13

Not all the genes are active

Question 14

Neural crest cells arose when?

Answer 14

Between Cephalachordata and Urochordata

Question 15

Neural crest cells are—

Answer 15

Migratory

Question 16

What are some derivatives of Neural Crest Cells?

Answer 16

Schwann cells, branchial cartilage cells, odontoblasts, dermis of the face, heart

Question 17

What helps organize vertebrate head and nervous system?

Answer 17

Ectodermal placodes

Question 18

Ectodermal placodes form what?

Answer 18

lateral line, cranial nerves, sensory epithelium of the olfactory system, lens of the eye

Question 19

Where did a patterning inversion of the body plan take place

Answer 19

Before te protostomes and then again Following the Ambulacraria branch

Question 20

the Spemann organizing center expresses what genes as the dorsal lip forms?

Answer 20

The Noggin gene (over expression causes extra-large head)

Question 21

Morphogens do what?

Answer 21

Induce cell differentiation and migration

Question 22

When does Dorsal-Ventral patterning begin?

Answer 22

At fertilization when sperm entry reorganizes cytoplasm

Question 23

How are the animal and vegetal poles determined?

Answer 23

Beta-catenin protein accumulates on the dorsal side of the fertilized egg

Question 24

Where does the dorsal lip form?

Answer 24

Opposite the site of the sperm entry

Question 25

The BCNE center cells form what?

Answer 25

the brain and the notochord

Question 26

What gene is expressed on different sides in late stage development of deuterostomes?

Answer 26

Nodal

Question 27

Anterior-posterior genes also involved in patterning are…

Answer 27

Hox genes

Question 28

What controls Hox gene expression?

Answer 28

maternal factors and other genes

Question 29

Any structure derived from a somite is controlled by what genes at some point?

Answer 29

Hox

Question 30

Hox clusters are on how many chromosomes in vertebrates?

Answer 30

4

Question 31

More genes=??

Answer 31

more evolution

Question 32

What genes are involved in limb loss/regrowth by reptiles?

Answer 32

Hox

Question 33

What affects which genes are preserved in a lineage?

Answer 33

Natural selection