Lecture 1: introduction and Gametogenesis 1

Question 1

Define ontogeny

Answer 1

Includes all developmental processes from contraception to death

Question 2

Define embryogeny

Answer 2

the part of ontogeny from contraception to birth

Question 3

Define determination

Answer 3

process by which a cell or part of an embryo becomes restricted to a given developmental pathway

Question 4

Define differentiation

Answer 4

complex changes involved in specialization of structure and function

Question 5

Define morphogenesis

Answer 5

generation of form or assumption of new shape

Question 6

Define induction

Answer 6

effect that one embryonic tissue has on another that changes the development that changes it from if the inhibitor had been absent

Question 7

Define integration

Answer 7

process by which different tissues are brought together and combined

Question 8

When is the first appearance of germ cells in humans?

Answer 8

24 hours after fertilization

Question 9

Define teratomas

Answer 9

growths from misdirected migrating primordial germ cells with mixtures of highly differentiated tissues

Question 10

What are the 5 stages of prophase 1?

Answer 10

1. leptotene
2. zygotene
3. pachytene
4. diplotene
5. diakinesis

Question 11

What are the major results of meiosis?

Answer 11

1. increase in cell numbers
2. daughter cells are not genetically identical
3. daughter cells are haploid

Question 12

Describe leptotene

Answer 12

first stage of prophase one:

• chromosomes are threadlike
• chromosomes consists of two chromatids
• chromosomes begin to coil

Question 13

Describe zygotene

Answer 13

-homologous chromosome pair (synapsis); synaptonemal complex forms

Question 14

Describe pachytene

Answer 14

• maximum coiling
• tetrads
• crossing over begins

Question 15

Describe diplotene

Answer 15

• crossing over continues

- chiasmata well defined

Question 16

Describe diakinesis

Answer 16

• crossing over is complete
• terminalization
• spindle apparatus in place
• nuclear membrane disrupted

Question 17

What happens in the event of a nondisjunction?

Answer 17

Aneuploidy

Question 18

What are mutations that cause changes in part of a chromosome?

Answer 18

translocations
deletions
inversions
duplications

Question 19

Describe the fetal period in regards to follicular structure

Answer 19

the diploid oogonium is not surrounded by follicle cells

there is no follicle

1 chromatid/chromosome

Question 20

Describe the later fetal period through birth

Answer 20

primary oocyte has advanced to the diploid stage of meiosis
primordial follicle with flattened follicle cells

2 chromatids.chromosome

Question 21

Describe the follicular structure in regards to birth to puberty

Answer 21

-diploid primary oocyte
-primary follicle with a single layer of cuboidal follicle cells
-connected via gap junctions
zona pellucida separates primary oocytes from follicular cells
2 chromatids/chromsome

Question 22

List the components of the Tertial Graafian follicle from external to internal

Answer 22

1. theca externa (produce angiogenesis)
2. theca interna (LH receptors, secrete testosterone)
3. membrana granulosa
4. mural granulosa (develop FSH receptors, synthesize aromatase in response to FSH which converts testosterone)
5. antrum
6. cumulus (facilitate release of ovum)
7. zona pellucida
8. oocyte

Question 23

What are the characteristics of the Graafian follicle

Answer 23

Large
projects from ovary
9 day development

Question 24

What does the egg accumulate from external sources?

Answer 24

via heterosynthesis through follicle cells or nurse cells; yolk manufactured in the liver

Question 25

What does the egg accumulate from itself?

Answer 25

via autosynthesis | lamp brush chromosomes, gene amplification

Question 26

Describe the corona radiata

Answer 26

layer of follicle cells surrounding the oocyte and interacts via gap auctions and microvilli

Question 27

Describe the zona pellucida

Answer 27

non-cellular membrane that is secreted ny the corona radiata and oocyte