Chapter 10: Meiosis

Question 1

Locus

Answer 1

a genes specific location on a chromosome

Question 2

Somatic Cells

Answer 2

normal cells in an organism

Question 3

Gametes

Answer 3

reproductive cells that pass genes

Question 4

What are autosomal chromosomes

Answer 4

The first 1 to 22 chromosomes in a human

Question 5

What are sex chromosomes

Answer 5

The last pair 23 chromosomes in a human the X and Y ones

Question 6

Haploid and Diploid

Answer 6

Chromosome pairs in a human are diploid because we get one from each parent. Gametes are haploid and only have 1 chromosome instead of a pair

Question 7

What is the total process of meiosis

Answer 7

Meiosis takes a diploid germ stem cell and produces four haploid gamete

Question 8

What is the total process of fertilization

Answer 8

The merging of two haploid gametes to form a diploid zygote

Question 9

What is karotype

Answer 9

the variation between XX (female) and XY (male)

Question 10

Variations in karotype hormones

Answer 10

Males have higher rations of androgens while females have higher ratios of estrogen

Question 11

SRY gene

Answer 11

A gene on sex chromosomes that also determines a male, several mutations in this gene can make a female have XY chromosomes (no SRY on y chrome) or a male have XX chromosomes (SRY on X chrome)

Question 12

Ploidy

Answer 12

the number of sets of chromosomes in a cell

Question 13

What is homologous recombination?

Answer 13

When meiosis mixes the homologous chromatids in the parent to make something new called recombinant chromosomes

Question 14

What happens in Meiosis I

Answer 14

homologous recombination changes the duplicated (s phased) sister chromatids and makes them recombinant but duplicated haploids

Question 15

What happens in Meiosis II

Answer 15

The recombinant haploids fully separate and no longer duplicated

Question 16

What is crossing over

Answer 16

Another name for homologous recombination, occurs during prophase

Question 17

When does independent assortment occur?

Answer 17

metaphase and anaphase

Question 18

What three things contribute to gene variation in a child

Answer 18

homologous recombination, independent assortment and fertilization

Question 19

What is a chiasmata

Answer 19

An x shaped structure made by two chromosomes undergoing homologous recombination

Question 20

What are the steps of recombination

Answer 20

Step 1 - DNA in chromosome are broken by protein, only one chromatid of each sister chromatid

Step 2 - Proteins hold the two non sister chromatids and form a synaptonemal complex

Step 3 - Synapsis fuses the pairs, homologous recombination occurs and recombinant chromosomes are created

Step 4 - synaptonemal complex leaves, chiasmata is visible, two pairs of sister chromatids are connected by their crossovers.

Question 21

How many crossovers are on the average human chromosome?

Answer 21

two to three

Question 22

What is independent assortment

Answer 22

A variation in meiosis that happens during anaphase caused by a varying of where the homologous chromosome is facing

Question 23

Why are they 2 PMATs in Meiosis

Answer 23

The first Meiosis PMAT splits of the pair of sister chromatids that are attached to each other, then the second splits the sister chromatids into just chromatids making 4 new cells.