Ch. 11

Question 1

meisosi

Answer 1

form of cell division that leads to the production of gametes

Question 2

diploid

Answer 2

2 sets of chromosomes

Question 3

haploid

Answer 3

only 1 set of chromosomes

Question 4

meiosis includes two rounds of division

Answer 4

meiosis I and meiosis II

Question 5

during meiosis I, homologous chromosomes become closely associated with each other

Answer 5

synapsis

Question 6

proteins between the homologues hold them in

Answer 6

synaptonemal complex

Question 7

the complex with the chromosomes is a

Answer 7

tetrad

Question 8

crossing over

Answer 8

genetic recombination between non-sister chromatids

Question 9

chiasmata

Answer 9

site of crossing over

Question 10

crossing over occurs at

Answer 10

holliday junction

Question 11

prophase I

Answer 11

chromosomes coil tighter
nuclear envelope dissolves
homologues become closely associated in synapsis

Question 12

metaphase I

Answer 12

terminal chiasmata hold homologous together after crossing over
microtubules from opposite poles attach to each homologue
homologues are aligned at metaphase plate side-by-side

Question 13

anaphase I

Answer 13

microtubules of spindle shorten
homologues separate from each other

Question 14

telophase I

Answer 14

nuclear envelope forms around each set of chromosomes
each new nucleus is now haploid
sister chromatids are no longer identical due to crossing over

Question 15

nondisjunction

Answer 15

failure of chromosomes to move to opposite poles during either meiotic divisions

Question 16

aneuploid gametes

Answer 16

gametes with missing or extra chromosomes
most common cause of spontaneous abortion in humans