Biology ch. 5.3

Which of the following is a form of asexual reproduction?

Fragmentation

How many chromosomes do gametes have? How many chromosomes do zygotes have?

Gametes contain only half the number of chromosomes found in other cells of the organism. A zygote is a diploid cell, which means that it has twice the number of chromosomes as a gamete.

What is gametogenesis? What is the term called in males? In females?

Gametogenesis is the development of haploid cells into gametes. The term called in males is sperm. The term called in females is eggs.

Example - Budding

Yeast

Organisms that have a life cycle with _______ generations switch back and forth between diploid and haploid stages

alternating

Homologous chromosomes separate during

anaphase I

When cells divide during meiosis, homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate _______ of each other

apart

Binary fission, fragmentation, and _________ are types of asexual reproduction

budding

After meiosis there are

four haploid cells

Crossing-over is the exchange of _______ material between homologous chromosomes.

genetic

Meiosis is a type of cell division in which the number of chromosomes is reduced by ________.

half

The _____ life cycle is the simplest life cycle

haploid

Differences between meiosis I and meiosis II include:

how the chromosomes line up at the equator of the cell during meiosis I or meiosis II, the pairing of chromosomes in meiosis I but not meiosis II, the amount of DNA in a cell at the end of meiosis I or meiosis II.

The random distribution of homologous chromosomes during cell division is known as

independent assortment

A life cycle in which organisms switch back and forth between diploid and haploid stages

is an alternation of generations life cycle

Description - Binary fission

occurs when a parent cell splits into two identical daughter cells of the same size.

Description - Fragmentation

occurs when a parent organism breaks into fragments, or pieces, and each fragment develops into a new organism

Because of when the chromosomes pair up during meiosis, crossing-over must occur during

prophase I

Male gametes are called ______, and female gametes are a _______ cell

sperm, egg

Example - fragmentation

starfish

Sexual reproduction involves ________ parents.

two

Which of the following is true about a zygote? (1) A zygote is the first cell of a new organism. (2) A human zygote has 23 pairs of chromosomes. (3) A zygote is produced through fertilization.

1, 2, and 3

A human egg cell has ________ chromosomes

23

Meiosis begins with one cell, and ends with ______ cells

4

A human zygote has ______ chromosomes

46

Asexual Reproduction

Binary Fission, Fragmentation, and Budding

During _________, spindle fibers attach to the paired homologous chromosomes

Metaphase 1

Description - Budding

Occurs when a parent cell forms a bubble like bud. The bud stays attached to the parent cell and forms a new organism

Example - Binary fission

Prokaryotic cells

Offspring resulting from sexual reproduction and those resulting from asexual reproduction differ in one major way. What is the difference?

Sexual reproduction produces genetically different offspring. Asexual reproduction produces genetically identical offspring.

List advantages and disadvantages of asexual reproduction (binary fission).

Some advantages are it happens very rapidly and can happen with only one parent. Some disadvantages are that many asexual reproducers can not live under ideal conditions and that they can be in a lot of places you don't want them to be.

List advantages and disadvantages of sexual reproduction

The advantages of sexual advantages are it involves two parents and that the result of offspring are genetically unique. The disadvantages are that it takes longer and that many problems can happen during sexual reproduction.