Meiosis (tutorial #10)

Question 1

Asexual Reproduction

Answer 1

Reproduction in which organisms produce genetically identical offspring (clones)

Question 2

Sexual Reproduction

Answer 2

When the genetic material from two parents combines to form offspring that are genetically distinct from their parents.

Question 3

Gene

Answer 3

A heritable unit that codes for the production of a protein.

Question 4

Allele

Answer 4

The different alternative forms of a gene

Question 5

How many chromosomes are in the human genome?

Answer 5

46

Question 6

Homologous chromosomes

Answer 6

paired chromosomes that carry the same genes, one from each parent.

Question 7

Gametes

Answer 7

Reproductive cells termed sperm and eggs; each gamete cell only has 23 chromosomes, which makes it haploid (n)

Question 8

What ploidy level are somatic cells?

Answer 8

Diploid (2n) because they have one complete set of chromosomes from each parent (23 from mom, 23 from dad, 46 total).

Question 9

What does 2n mean?

Answer 9

2n means there are two complete sets of chromosomes. 2n is associated with the term diploid.

Question 10

What does n mean?

Answer 10

n means that there is one complete set of chromosomes. n is associated with the term haploid.

Question 11

fertilization

Answer 11

when male gametes (sperm) and female gametes (egg) unite together. This begins the formation of a zygote during a process called sexual reproduction.

Question 12

Zygote

Answer 12

A diploid cell resulting from the fusion of two haploid gametes.

Question 13

Homologous pair

Answer 13

A pair of chromosomes with the same genes in the same locations, but different versions of those genes.

Question 14

What is the primary function of meiosis?

Answer 14

The proper distribution of homologous chromosomes to gametes

Question 15

What are the three phases of meiosis?

Answer 15

1. pairing up the homologous chromosomes
2. synapsis of the chromosomes together (crossing over)
3. separating the chromosomes into daughter cells

Question 16

If a diploid cell goes through meiosis, how many daughter cells will be produced? what is the ploidy level of each of those daughter cells?

Answer 16

Four haploid daughter cells are produced.

Question 17

What is the difference between sister chromatids and non-sister chromatids?

Answer 17

Sister chromatids are two identical copies of a chromosome that are joined together by a centromere. Non-sister chromatids are two chromatids from two different homologous chromosomes.

Question 18

What are the two factors that give rise to genetic diversity in meiosis?

Answer 18

independent assortment and crossing over (or recombination).

Question 19

Independent assortment

Answer 19

Occurs during metaphase I when the homologous chromosomes line up on the metaphase plate. The orientation of the pairs is random, which allows for different combinations of chromosome pairs in daughter cells.

Question 20

How do you find the number of different combinations of pairs of chromosomes in a daughter cell?

Answer 20

2^n, where n is equal to the number of chromosome pairs

Question 21

crossing over/recombination

Answer 21

when pieces of one chromosome may be exchanged with the identical portion of the other chromosome in a homologous pair. This means that the resulting chromosomes are a unique mixture of maternal and paternal chromosomes.

Question 22

Approximately how many times does crossing over occur in humans?

Answer 22

2-3 times per chromosome pair; ONLY HAPPENS IN NON-SISTER CHROMATIDS IN MEIOSIS I).