CH 9 HW

Once meiosis I is completed, cells are....

Haploid.

G1 Check point

Is cell / necessary? Are growth factors present? Is cell large enough? are sufficient nutrients available?

Gametes are produced by _____.

Meiosis

The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?

Telophase (4th and final stage)

A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.

16 (half of 32).

Normal human gametes carry _____ chromosomes.

23

Sexual Reproduction

Each kid inherits a particular combination of genes from two parents; so many combinations are possible that each kid is essentially unique.

True or false. Mitosis takes place during M phase of the cell cycle, which is longer than interphase.

False. Mitosis does take place during M phase, but M phase is shorter than interphase.

Organisms that have a single copy of each gene are called _______.

Haploid -having one of each type of chromosome (n) Bacteria and archaea are haploid, many plant and animal gametes are haploid.

A pair of chromosomes made of members from two parents is called __________.

Homologous Chromosomes - set of one mom chromosome and one dad chromosome that pair up with each other inside a cell during mitosis.

The chromosomes line up in the center of the cell during which phase of mitosis?

Metaphase (2nd stage)

Asexual reproduction

Mitosis makes it possible for organisms to reproduce asexually (Solo), by producing cells that carry the same genes as the parent cells

The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?

Prophase (1st stage)

What must happen before a cell can begin mitosis?

The chromosomes must be duplicated. (Interphase)

At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________.

cytokinesis (the division of the cytoplasm that occurs in conjunction with telophase)

A certain species of animal has six pairs of chromosomes. How many DNA molecules are present in the nuclei of these animals during G2 phase?

24 (Since each chromosome (12) is replicated, there are 24 DNA molecules in the nucleus during G2 phase.

Which of the following checkpoints does not occur late in G1? A check that the cell is large enough for division A check that chromosome replication has been successfully completed A check that growth factors are present A check that nutrients are sufficient

A check that chromosome replication has been successfully completed. (Chromosome replication does not occur until after G1; this checkpoint is a G2.)

The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?

Anaphase (3rd stage)

Metaphase Check point

Are all chromosomes attached to the microtubules?

In eukaryotic cells, chromosomes are composed of both DNA and proteins. True or False?

True

G2 Check point

Was DNA replicated right? Is cell large enough?