Mitosis and Meiosis Review

Name 3 differences and 1 similarity between mitosis and meiosis

Mitosis & Meiosis: Both have PMAT

Mitosis: occurs in somatic cells, creates 2 (identical) daughter cells and helps with growth and repair for asexual reproduction

Meiosis: occurs in reproductive organ cells, creates 4 (different) daughter cells and helps with producing gametes for sexual reproduction

Human gamete cells contain how many chromosomes?

23

Are human gametes haploid or diploid?

Haploid

What is the cell cycle?

When the cell grows,

prepares for division, & divides, forming two daughter cells, each of which begins the cycle again

What is a chromosome?

Threadlike structures in the cell, containing genetic info (DNA) that is passed on from one generation of cells to the next

What is crossing over?

Homologous chromosomes exchange portions of their chromatids during meiosis (specifically prophase)

What is diploid?

Two sets (2N); description of cell containing a double set of chromosomes (One from each parent)

What is a gamete?

Specialized reproductive cell involved in sexual reproduction (sperm or egg cells); formed through meiosis

What is haploid?

Containing a single set of chromosomes (sperm or egg cell) (N)

What is homologous?

Description of chromosomes that occur in pairs; having a corresponding structure

What is mitosis?

Nucleus divided into two nuclei, each with same number and kinds of chromosomes as the parent cell

What is meiosis?

Process of reduction division. Number of chromosomes per cell are cut in half and the homologous chromosomes that exist in a diploid cell are separated; produces haploid gametes from diploid cells

What is tetrad?

Structure containing 4 chromatids that form during meiosis

When does crossing over happen in meiosis?

Meiosis 1, specifically Prophase 1

How many chromosomes do humans have (diploid # 2N)?

46

How many chromosomes do human gamete (egg and sperm) cells have (haploid #N)?

23

Human somatic (body) cells contain how many chromosomes?

46

Are somatic cells haploid or diploid?

Diploid

When does crossing over happen in meiosis?

Meiosis 1, specifically in prophase 1

Stage of mitosis where chromatids of each chromosome separated & are moving toward the poles

Anaphase

Stage of mitosis where the thick, coiled chromosomes, each with two chromatids, are lined up across the center (metaphase plate, equator or midline) of the cell

Metaphase

Last phase of mitosis. the chromosomes are at the poles becoming more diffuse (uncoil). nuclear envelope is reforming around the chromatin, new centrioles begin to form and spindles disappear. By the end of this phase, two nuclei form.

Telophase

Period in the cell cycle between cell divisions. nucleolus and nuclear envelope are distinct and the chromosomes are in the form of threadlike chromatin. It is divided into three stages: G1 (Cell growth), S (DNA replication), and G2 (preparation for cell division).

Interphase

First phase of mitosis. The nuclear envelope begins to break down, cytoplasm becomes viscous and chromosomes appear condensed

Prophase

(Mitosis) Cells cytoplasm divides to form two distinct cells; division into two daughter cells is completed.

Cytokinesis

Where does the cell spend most of the time in?

Interphase

How many divisions are in mitosis and meiosis?

Mitosis:1

Meiosis:2

How many daughter cells are produced in mitosis and meiosis?

Mitosis:2

Meiosis:4

Does mitosis and/or meiosis have genetically identical cells?

Mitosis: yes

Meiosis: no

What are the chromosome numbers for mitosis and meiosis?

Mitosis: same as parent results in identical diploid (2N) daughter cells

Meiosis: 1/2 Parent reduction division results in haploid (n) cell

Where/When does mitosis and meiosis happen?

Mitosis: in somatic (body) cells; throughout life

Meiosis: only in cells in gonads (sex organs: ovaries/testes); at sexual maturity

What are the roles of mitosis and meiosis?

Mitosis: growth and repair for asexual reproduction

Meiosis: produces gametes (sex cells: egg/sperm) for sexual reproduction

REMINDER look at pictures with cell phases (mitosis and meiosis)

they are on the note sheets, on the pictures taken during class and on the take-home quiz