Chapter 19 Part 2

Question 1

Meiosis is __ divisions that result in up to __ __________ daughter cells

Answer 1

2; 4 haploid

Question 2

2 functions of meiosis

Answer 2

• keeps the number of chromosomes in a body cell constant from generation to generation
• increases the genetic variability in a population

Question 3

Meiosis 1 produces

Answer 3

2 cells each with 23 chromosomes (each daughter cell contains one member of each homologous pair, with each chromosome consisting of two sister chromatids)

Question 4

Prophase 1

Answer 4

• chromosomes condense
• synapsis occurs
• crossing over takes place

Question 5

Synapsis

Answer 5

Members of homologous pairs line up next to one another

Question 6

Crossing over

Answer 6

Parts of non-sister chromatids are exchanged

Question 7

Metaphase 1

Answer 7

• Homologous pairs of chromosomes line up at middle of cell

* spindle fibers from each pole attach to one member of each pair

Question 8

Anaphase 1

Answer 8

• homologues separate

Question 9

Telophase 1

Answer 9

• one member of each homologous pair is at each pole
• cytokinesis occurs and forms 2 haploid daughter cells
• each chromosome still consists of two chromatids

Question 10

Telophase 1 is followed by

Answer 10

Interkinesis

Question 11

Interkinesis differs from telophase in that..

Answer 11

No replication of DNA takes place

Question 12

Prophase 2

Answer 12

Chromosomes condense in both daughter cells

Question 13

Metaphase 2

Answer 13

Chromosomes line up in middle of cell

Question 14

Anaphase 2

Answer 14

• Centromeres separate
• chromatids are now chromosomes
• chromosomes move to opposite poles

Question 15

Telophase 2

Answer 15

One complete set of chromosomes at each pole and cytokinesis occurs forming 4 haploid daughter cells

Question 16

Spermatogenesis

Answer 16

Produces 4 sperm cells

Question 17

Oogenesis

Answer 17

Produces one ovum and 3 polar bodies (nonfunctional cells)

Question 18

Independent assortment

Answer 18

During metaphase1, homologous pairs align randomly in the center of the cell so when they separate during meiosis they form a random combo of chromosomes in the daughter cells

Question 19

Nondisjunction

Answer 19

The failure of homologous chromosomes to separate during meiosis 1 or of sister chromatids to separate during meiosis 2

Question 20

Trisomy

Answer 20

3 of one chromosome

Question 21

Monosomy

Answer 21

Only one representative of a particular chromosome

Question 22

Turner syndrome XO

Answer 22

• thick fold of skin on neck
• shorter
• wide chest
• underdeveloped breasts
• usually infertile

Question 23

Klinefelter syndrome XXY

Answer 23

• testes Small
• testosterone insufficiency
• taller than average
• facial/ body hair may fail to develop fully
• May be sterile

Question 24

Triple-X syndrome

Answer 24

Some have learning disabilities and delayed language skills

Question 25

Jacob syndrome XYY

Answer 25

Taller than normal and some have slightly lower than normal intelligence