Lecture 1: Introduction/Gametogenesis I

Question 1

Embryology

Answer 1

Study of the embryo, can be descriptive or experimental

Question 2

Ontogeny

Answer 2

Includes all developmental processes from conception to death

Question 3

Embryogeny

Answer 3

That part of ontogeny from conception to birth/hatching

Question 4

Determination

Answer 4

Process by which a cell/part of an embryo becomes restricted to a given developmental pathway

Question 5

Differentiation

Answer 5

Complex of changes involved in progressive specialization of structure/function, often resulting in the formation of luxury molecules

Question 6

Growth

Answer 6

Permanent increase in mass; hyperplasia or hypertrophy

Question 7

Morphogenesis

Answer 7

Generation of form/assumption of new shape

Question 8

Induction

Answer 8

An effect of an inductor on a responder such that the developmental course of responder is qualitatively changed from what it would have been in the absence of the inductor

Question 9

Integration

Answer 9

Process by which different tissues are brought together and combined to form organs and tissues

Question 10

Phase 1: Gametogenesis

Answer 10

Extraembryonic origin of germ cells and migration to gonads

Question 11

Phase 2: Gametogenesis

Answer 11

Increase in number of germ cells by mitosis

Question 12

Phase 3: Gametogenesis

Answer 12

Reduction in chromosomal number by meiosis

Question 13

Phase 4: Gametogenesis

Answer 13

Structural/functional maturation of the eggs and spermatozoa

Question 14

Where/when do primordial germ cells first appear following fertilization?

Answer 14

Yolk sac, 24 days after fertilization (humans)

Question 15

What is the migration route of the germ cells from the yolk sac to the developing gonads?

Answer 15

yolk sac, hindgut epithelium, dorsal mesentery, developing gonads

Question 16

Teratoma

Answer 16

Tumor-like growths from misdirected migrating primordial germ cells containing mixtures of highly differentiated tissues

Question 17

Major events in meiosis

Answer 17

Synapsis, crossing over, 2 cell divisions, 1 cycle of DNA replication

Question 18

Major results of meiosis

Answer 18

Increase in cell numbers, genetically unique and haploid daughter cells

Question 19

Prophase I - Leptotene

Answer 19

Threadlike chromosomes with 2 chromatids begin to coil

Question 20

Prophase I - Zygotene

Answer 20

Synapsis occurs, synaptonemal complex forms

Question 21

Prophase I - Pachytene

Answer 21

Maimum coiling, tetrads, crossing over begins

Question 22

Prophase I - Diplotene

Answer 22

Crossing over continues, chiasmata well defined

Question 23

Prophase I - Diakinesis

Answer 23

Crossing over complete, terminalization, spindle apparatus in place, nuclear membrane disrupted

Question 24

Metaphase I

Answer 24

Tetrads line up along equatorial plate, centromeres do not divide

Question 25

Anaphase I

Answer 25

Homologous chromosomes move to opposite poles, each consisting of 2 genetically unique chromatids

Question 26

Telophase I

Answer 26

Cytokinesis occurs, nuclear membranes reform, spindle apparatus disassembles, chromosomes may uncoil

Question 27

Prophase II

Answer 27

Chromosomes condense, nuclear membrane disappears, spindle apparatus reforms

Question 28

Metaphase II

Answer 28

Chromosomes line up on equatorial plate

Question 29

Anaphase II

Answer 29

Centromeres divide, chromosomes move to opposite poles, each chromosome has single chromatid

Question 30

Telophase II

Answer 30

Chromosomes uncoil, cytokinesis complete, nuclear membranes reform
END RESULT: 4 genetically unique haploid daughter cells

Question 31

Aneuploidy

Answer 31

Abnormal number of chromosomes; ex: monosomy, trisomy

Question 32

Euploidy

Answer 32

Changes in the number of complete sets of chromosomes; ex: monoploidy, diploidy, polyploidy