Sexual reproduction day 2 (regents)

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what happens in meiosis 1?

chromosomes replicate through synapsis and crossing over

Each chromosome pair is separated into two daughter cells

• Each cross consists of 2 chromosomes

Disinjunction

what happens in meiosis 2?

each pair is divided into two new daughter cells

in meiosis 2, after rach pair is divided into two new daughter cells, next each chromosome is divided into ___ new daughter cells

two

Result of meiosis two: ____ daughter cells that have ____ of the original genetic infofrmation than the parent cell.

Four daughter cells that have half

failure of homologous chromosome to seperate which results in extra of a missing chromosome in the gamete

non-disinjunction

Sexual reproduction is a type of reproduction which involves ___ ______ which results in the offspring being __________ from either parent

Two parents, which results in the offspring being different from either parent.

Benefit of sexual reproduction…Genes come from two parents instead of one. So all individuals are different

Diversity

benefit or sexual reproduction: Individuals with genetic variation better suited to handle environmental and biological issues will survive

Evolution

Disadvantages of sexual reproduction: when two sets of genes combine to make an offspring, diseases, disabilities, and illnesses are much more common than in asexually reproducing organisms.

Genetic mutations

Disadvantages of sexual reproduction: The time it takes to conceive and give birth to an offspring is much longer than asexual reproduction

Time

Disadvantages of sexual reproduction: it requires a lot of time, energy, and effort to find a suitable someone to reproduce with

finding a mate

Cell division that produces cells that are different than the parent cells. this reduces the number of chromosomes bt one half

meiosis

Sex cells produced by the process of meiosis that have half the number of chromosomes comapred to somatic (body)

Gametes

Where does meiosis occur?

Gonads

Sex organs that produce sex cells by the process of meiosis

• male: testes

• female: ovaries

gonads

Sex cells are _____?

haploid

What are sex cells function?

To produce new offspring

Why is it essential to reduce the number of chromosomes by half during meiosis?

• When sperm and egg meet, ____________ of chromosomes is restored

normal number

Why is it essential to reduce the number of chromosomes by half during meiosis?

• Ex: humans have ___ chromosomes in the sperm and 23 chromosomes in the egg. When the sperm and egg unite, the total is __ chromosomes.

23, 46

How is meiosis the source of variation for sexual reproduction?

• There are two reasons meiosis causes variation, which means no two sperm or egg cells are _______

identical

___________ during meiosis allows homologous chromosomes to exchange genes

crossing over