Module 8- Meiosis and Sexual Reproduction

Question 1

In Asexual reproduction…

Answer 1

offspring identical to parent (clones)

Question 2

Which organisms reproduce asexually?

Answer 2

Plants are easy to asexually reproduce, Yeast can by mitosis ( budding), some forms of the animal kingdom

Question 3

What is an explanation for sexual reproduction?

Answer 3

sexual productions introduces variation in the comnination of traits among offspring

Question 4

Why is this thought to be the case for sexual reproduction?

Answer 4

Adaptations spread more quickly through a sexually reproducing population than through an asexually reproducing one.

Question 5

What is a Karyotype?

Answer 5

Illustration of the traits of an individual usually taken from metaphase and place in order based on their size

Question 6

How many somatic cells are in a human body?

Answer 6

22 pairs

Question 7

What are the remainder of non-somatic cells called?

Answer 7

sex chromosomes

Question 8

In meiosis, there are….

Answer 8

2 divisions of the nucleus followed by 2 cytoplasmic divisions form 4 haploid daughter cells.

Question 9

What are the Products of Meiosis?

Answer 9

Animals- gametes ( sperm and egg)
Plants- spores

Question 10

In the animal kingdom, female choice leads to

Answer 10

male competition

Question 11

In plants,…

Answer 11

Antheres where sexual spores that give ise to sperm form
Ovules inside the ovary where sexual sporea that give rise to eggs form

Question 12

_____forms cells that are genetically the same _____ does not=

Answer 12

Mitosis/meiosis

Question 13

Explain Meiosis I

Answer 13

Crossing over
Occurs in Prophase I
Each homologous chromosome can pair up and fuse with the other member- Called Synapsis, THEY FORM A TETRAD
Arms of each chromosome are called chromatids (CHIASMATA)
Chromatids can break off and be exchanged with one another- new combinations of alleles can be introduced into those gamete cells
They will remain fuses until M
* Random alignment of chromosomes in Metaphase I (HOW THE CHROMOSOMES ALIGN WLL INTRODUCE GENETIC VARIATION AS THERE IS NO PLAN ON HOW TO LINE UP) and will be pulled apart in anaphase I

Chromosomes numbers are reduced by half (this introduces genetic variation)

Question 14

Explain Meiosis II

Answer 14

Same division as mitosis (no genetic variation)
No interphase- chromosomes are always replications
Nothing occurs in Meiosis II that is different from Mitosis
In Meiosis ii- cells are not genetically identical

Question 15

Which aspects of sexual reproduction are random?

Answer 15

1) Crossing over in Prophase I
2) Random alignment of chromosomes in Metaphase I
3)Random fusion of gametes
4) Mutations

Question 16

True or false: Mating is a random act of genetic variance?

Answer 16

False

Question 17

Compare Mitosis compared with Meiosis.

Answer 17

Mitosis:
Somatic cells
Body cells
1 divisions
2 daughter cells
Daughter cells are clones of the parent cells
Crossing over does not occur in prophase
Chromosome number is the same in daughter cells as parent cell
Anaphase- sister chromatids separate

Meiosis: (Each of the 23 chromosomes have 2 chromatids)
Germ cells
2 divisions
2 daughter cells
daughter cells are not genetically identical to parent cell
Crossing over occurs in prophase 1
Chromosome number is reduced by ½ in daughter cells
Anaphase I- Homologous chromosomes separate

Question 18

What is a tetrad

Answer 18

Two pairs of sister chromatids