Cell Division

Question 1

chromosomes are at their greatest
elongation (not visible)
- begin to coil, become more condensed

Answer 1

Prophase

Question 2

nuclear membrane disappears
- spindle fibers : begin to appear
- chromosomes attach to the spindle fiber at their kinetochores.

Answer 2

Prometaphase

Question 3

chromosomes attach to the spindle fiber
-surface of centromere

Answer 3

Kinetochores

Question 4

Chromatin condenses into chromosomes
Nucleolus disappears

Answer 4

Prophase

Question 5

mitotic spindle completed
-centrioles: divide and move to opposite poles
- chromosomes: line up on the equatorial plate,reach their maximum state of contraction.

Answer 5

Metaphase

Question 6

centromeres: divide longitudinally
chromatids: separate and migrate to opposite poles

Answer 6

Anaphase

Question 7

Chromosomes break at centromeres, and sister chromatids move to opposite ends of the cell

Answer 7

Anaphase

Question 8

Chromosomes: uncoil, become
indistinguishable again.
Nucleoli: reform
Nuclear membrane: reconstructed
Followed by cytokinesis, or cytoplasmic division

Answer 8

Telophase

Question 9

What appears during telophase

Answer 9

Cleavage furrow

Question 10

takes place only in the ovaries and testes

Answer 10

Meiosis

Question 11

Longest phase in meiosis

Answer 11

Prophase I

Question 12

Complex stage that is further
subdivided into:

Answer 12

Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis

Question 13

 There are 46 chromosomes, each comprised of two chromatids.
 Chromosomes begin to condense but are not visible by light microscopy.
 Once takes place, the cell is committed to meiosis.

Answer 13

Leptotene

Question 14

 Homologous chromosomes (long threadlike structures) pair locus for locus. —- SYNAPSIS: paring locus for locus
 A tripartite structure, the synaptonemal complex, can be seen in electron microscopy– necessary for the phenomenon of crossing-over that will takes place later in prophase I

Answer 14

Zygotene

Question 15

crossing over of genetic material
-chromosome becomes short and thick and divide into four distinct chromatids.

Answer 15

Panchtene

Question 16

 Chromosomes continue to shorten and thicken
 Homologous chromosomes begin to repel each
other
 Repelling continues until the homologous chromosomes are held together only at points where crossing over took place

Answer 16

Diplotene

Question 17

points where crossing over took place

Answer 17

Chiasmata

Question 18

chromosomes reach their greatest contraction during this last stage of prophase.

Answer 18

Diakenesis

Question 19

 Disappearance of the nuclear membrane and formation of the mitotic spindle. The bivalents line up on the equatorial plate with their centromeres randomly oriented toward opposite poles

Answer 19

Metaphase 1

Question 20

 The centromeres of each bivalent separate and migrate to opposite poles.

Answer 20

Anaphase 1

Question 21

 Two haploid sets of chromosomes reach opposite poles and cytoplasm divides.
 The result is two cells containing 23 chromosomes, each composed of two chromatids.

Answer 21

Telophase 1

Question 22

Net result=4 cells each of which contains 23 chromosomes consisting a single chromatid.

Answer 22

Meiosis 2

Question 23

Begins with sexual maturity and occurs throughout the post-pubertal life of a man.

Answer 23

Sprematogenesis

Question 24

The spermatids differentiate to become

Answer 24

Spermatozoa

Question 25

begins in prenatal life In females

Answer 25

Oogenesis

Question 26

suspended diplotene is referred to

Answer 26

Dictyotene

Question 27

How many potential four gametes produced each menstrual cycle is theoretically viable.

Answer 27

Only 1

Question 28

 The chromosomes of the egg and sperm produced in Meiosis II are each surrounded by a nuclear membrane within the cytoplasm of the ovum.  The pro-nuclei fuse to form the diploid nucleus of the zygote and the first mitotic division begins.

Answer 28

Fertilization