11.2 features of meiosis

Question 1

Meiosis in a diploid organism consists of two rounds of division, called what?

Answer 1

• meiosis I
• meiosis II

*each containing PMAT

Question 2

Meiosis I

Answer 2

• “reduction division”
• results in daughter cells that contain one homologous chromosomes from each chromosomal pair
• daughter cells have only haploid (n) number of chromosomes
• depends on homologous pairs behaving as a unit(not individually like in mitosis)

Question 3

Meiosis II

Answer 3

• two haploid (n) cells from meiosis I undergo a mitosis-like division without DNA replication
• to produce 4 haploid daughter cells

Question 4

Phrophase I of meiosis

Answer 4

• homologous chromosomes pair up (synapsis) & become closely associated
• 4 chromatids of the 2 homologues are closely associated

Question 5

synapsis

Answer 5

• during early prophase I of meiosis

- homologous chromosomes find each other and “pair”

Question 6

crossing over

Answer 6

• in meiosis
• exchange of chromatid segments between homologous chromosomes
• responsible for genetic recombination between homologous chromosomes

Question 7

chismata

Answer 7

• the sites of crossing over

- x shape can be seen with microscope,evidence of crossing over seen

Question 8

anaphase I

Answer 8

-homologues are pulled to opposite poles for each pair of chromosomes

Question 9

Why is meiosis I called reductive division?

Answer 9

-homologues separate, reducing chromosome number to the haploid state

Question 10

Difference between meiosis I and meiosis II

Answer 10

• meiosis I(reduction phase) results in daughter cells that contain one homologue from each pair
• meiosis II does not further reduce number of chromosomes but separates sister chromatid

Question 10

Difference between meiosis I and meiosis II

Answer 10

• meiosis I(reduction phase) results in daughter cells that contain one homologue from each pair
• meiosis II