6.6 Gamete Formation and Genetic Variation

In humans, each gamete (egg and sperm) receives ___ chromosome from each of the ____ homologous pairs. Each chromosome separates _______.

1, 23, independently

The result of oogenesis is ____ large ___.

1, egg

The result of spermatogenesis is: ___ _____ of ____ size with ______ _____ content.

4, sperm, equal, different, genetic

Any 2 parents will produce a zygote with over ____ _________ (2^23 x 2^23) possible _____ combos.

70 trillion, diploid

Crossing Over: a ____ exchange between ______ chromosomes during ______ 1 of meiosis. This DNA exchange that occurs during crossing over increases ______. This makes the number of genetic combos ______.

DNA, homologous, Prophase, variation, infinite

What is gamete formation called?

Gametogenesis

In females: 1. _______L the process by which eggs are produced 2. A ______ cell increases in size to become a large immature cell called a germ cell. 3. There is _____ division of the ______ during egg production resulting in ____ egg and smaller _____ ______. These don't have enough cytoplasm to survive and are eventually _____ ______. 4. An egg contributes: _____, ____, and ____ to the embryo.

Oogenesis, diploid, uneven, cytoplasm, larger, polar bodies, broken down, DNA, nutrients, cytoplasm

The chromosome that each gamete receives is a matter of _____. As a result, a human gamete has 2^23 (___ million for EACH male and female) different chromosome ______ that can be produced by ______. (independent assortment)

chance, 8, combinations, meiosis

Meiosis contributes to genetic variation in 3 ways: ______ ________, _____ _______, and _______ ______.

independent assortment, random fertilization, crossing over

Random fertilization: the ____ of __ independently produced ______.

joining, 2, gametes

Independent Assortment: the ____ distribution of _______ chromosomes during meiosis.

random, homologous

The farther apart 2 genes are located on a chromosome, the more likely they are to be _____ by crossing over.

separated

In Males: 1. ___________: the process by which sperm are produced 2. A ______ cell increases in size to become and large immature cell called a _____ cell. 3. Male gametes form _______ that will allow the sperm to ____ to an egg and fertilize it. 4. Sperm only contribute ____ to the embryo.

spermatogenesis, diploid, germ, flagella, swim, DNA

Sexual reproduction creates _____ combinations of ___ that are essential for ______.

unique, genes, evolution

A ______ is formed when egg and sperm _____ join.

zygote, randomly