Cell Biology Module 9: Meiosis

_______ reproduction is when each parent passes along half of genetic information to offspring

sexual

how are meiosis and mitosis similar?

cell division

start with parent cells and end with daughter cells

In meiosis, the parent cell divides how many times?

2

Mitosis and Meiosis starts with what kind of cell?

one diploid cell

Mitosis ends with what kind of cell and how many?

2 diploid

Meiosis ends with what kind of cell and how many?

4 haploid

In _____, the haploid cells are genetically distinct from the parent cell and each other

meiosis

what is the goal of meiosis I?

separate homologous chromosomes

What’s the goal of meiosis II?

separate sister chromatids

Meiosis I starts with one ____ cell and ends with two ____ cells

diploid, haploid

______ _ is the primary source of genetic diversity in gametes

Meiosis I

What happens in Prophase I of Meiosis? (think of what people do at a family reunion)

tetrads are built

crossover of chromosomes

what do recombinant chromosomes carry?

carry mixed genetic information

what happens in prometaphase I of meiosis I?

nuclear envelope around tetrads break down

spindle fibers start to pull

what happens in metaphase I of meiosis I?

tetrads have been pulled to middle

chromosomes line up randomly

what happens in anaphase I of meiosis I?

the proteins holding the tetrads break

homologous chromosomes in each tetrad are pulled to opposite ends

what happens in telophase I and cytokinesis of meiosis I?

homologous chromosomes are on opposite ends of the cell

plasma membrane pinches in

cytoplasm and organelles divide into 2 cells

what happens in prophase II of meiosis II?

a new set of spindle fibers form

what happens in prometaphase II of meiosis II?

the fibers attach and begin to pull on each of INDIVIDUAL chromosomes

what happens in metaphase II in meiosis II?

all the chromosome randomly align in middle

what happens in anaphase II of meiosis II?

sister chromatids are separated from one another to opposite ends of cell

what happens in telophase II of meiosis II?

nuclear envelope forms around each set of chromosomes

what happens in cytokinesis of meiosis II?

cytosol and organelles are split

4 haploid cells are made

_____ ______ increases genetic diversity

sexual reproduction

What are the two ways that diversity occurs in meiosis?

independent assortment

crossing over

_______ _______ is the random division of DNA into gametes

independent assortment

at what 2 phases of meiosis does independent assortment occur?

metaphase I
metaphase II

_____ ____ is the exchange of genetic information between non-sister chromatids in a tetrad

crossing over

crossing over creates what type of chromosomes?

recombinant

In crossing over, chromosomes have a mix of who’s genes? maternal, paternal, or both

both

At what phase of meiosis does crossing over occur?

prophase I

What is fertilization?

fusion of two haploid gametes generating one diploid cell

During fertilization, how many gametes are present?

multiple

What are the two reasons that diversity is good?

adapt

decreases likelihood of genetic diseases being passed along

______ reproduction is when the offspring receive DNA from ONE parent

asexual

asexual reproduction is produced during mitosis or meiosis?

mitosis

What organisms use asexual reproduction the most?

bacteria

describe the roles of meiosis and mitosis in the life cycle of a human.

1. meiosis makes gametes

2. fertilization combines them

3. mitosis grows the baby