3.1 Meiosis

Question 1

Somatic cells

Answer 1

-body cells
-Reproduce by cell division and make up the vast majority of an organism cells
-human somatic cells have 23 pairs of chromosomes for a total of 46 chromosomes

Question 2

Gametes (sex cells)

Answer 2

Gammetes have half the chromosomes of the parent cell
- They make up an extremely tiny fraction of the organism cells
-Male gametes are called sperm and female gametes are called eggs or ova

Question 3

Chromosome number

Answer 3

individuals of the same species have the same number of chromosomes
-if sexual reproduction involves the fusing of genetic material from two individuals, then why doesn’t the resulting offspring contain twice the number of chromosomes as the parents? To maintain the same number of chromosomes from generation to generation, there needs to be a way to reduce the number of chromosomes that are passed on from each parents.
-the process that produce gametes which have half the number of chromosomes as their parents is called meiosis

Question 4

Meiosis

Answer 4

-happens only in the cells that produced gametes
-sometimes called reduction division because it reduces the chromosome number by half
Ex. Each fruit fly gamete contains four chromosome; half of the genetic material of the parent

Question 5

Haploid

Answer 5

Cells with half the chromosome number of the parent are called hot void symbolized with a single “n”

Question 6

Diploid

Answer 6

cells that have a complete set of chromosomes are called diploid symbolized as “2n”

Question 7

Homologous chromosomes

Answer 7

-diploid somatic cells have their chromosomes arranged in pairs
-each chromosome has a corresponding chromosome, forming a pair
-pairs of corresponding chromosomes are called homologous chromosomes

Question 8

Stages of meiosis

Answer 8

-meiosis is composed of two phases, meiosis one and meiosis two
-meiosis produces four haploid gases

Question 9

Interphase

Answer 9

-the chromosomes replicate to form sister chromatids

Question 10

Prophase

Answer 10

-the chromosome, shortened and thickened and become visible with a light microscope

Question 11

Metaphase

Answer 11

-chromosomes be behaved differently than in mitosis during metaphase
-homologous chromosomes pair up along the equator

Question 12

Anaphase

Answer 12

-the pairs of homologous chromosome separate and move to opposite poles along with their sister chromatids
-the sister chroma heads, do not separate in meiosis one
-Meiosis one results in two daughter, but each has only one of the homologous, with its sister chromatid still attached

Question 13

Meiosis ii

Answer 13

-the sister chromatids the two daughter cells line up at the equator of the cell
-each chromatid is pulled to the opposite pole
-the nuclear membranes reform, and cytokinesis, resulting in four haploid cells called Gametes
-The second phase is similar to mitosis in which the sister chromatids separate
-but since meiosis two starts with two daughter cells, which both divided two, four daughter cells are produced.

Question 14

Mitosis versus meiosis

Answer 14

-same number of chromosomes in the parent cell to begin with
-Mitosis sister chromatids separate during anaphase
-meiosis sister chromatids stay together, but separate in meiosis 2
-mitosis has two daughter cells
-meiosis has four daughters cells
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