AP Bio Unit 5 Koehler

What is the G0 phase of the cell cycle?

A phase where cells do not undergo mitosis and remain in a non-dividing state, such as neurons.

What happens in the G1 phase of the cell cycle?

Cellular organs are duplicated.

What occurs during the S phase of the cell cycle?

46 chromosomes are duplicated, also known as DNA synthesis.

What is the main function of the G2 phase?

Preparation for mitosis, including centriole growth.

What does PMAT stand for in mitosis?

Prophase, Metaphase, Anaphase, Telophase.

What is cytokinesis?

The actual splitting of the cell after mitosis.

What main events occur during prophase?

Chromosomes condense, spindle fibers emerge, nuclear envelope breaks down, nucleolus becomes visible.

What occurs during prometaphase?

Chromosomes continue to condense, kinetochores appear, and microtubules attach to kinetochores.

What characterizes metaphase in mitosis?

The mitotic spindle is fully developed, and chromosomes line up at the metaphase plate.

What happens in anaphase?

Sister chromatids are pulled towards opposite poles as cohesin proteins break down.

What is the purpose of telophase?

Chromosomes begin to decondense, and the nuclear envelope material surrounds each set of chromosomes.

What is binary fission and in which organisms does it occur?

A method of asexual reproduction that occurs in prokaryotes and some single-celled eukaryotes.

How are cancer cells related to mitosis?

DNA mutations can lead to unchecked cell division, resulting in the formation of tumors and cancerous cells.

How does cytokinesis differ in plant cells compared to animal cells?

In plant cells, a cell plate forms; in animal cells, a cleavage furrow forms to split the cell.

What checkpoint occurs after G1?

Checks for enough nutrients and proper cell growth.

What is the role of checkpoints in the cell cycle?

They monitor factors like DNA mutations, proper replication, and chromosome alignment.

What characterizes non-dividing cells?

They enter the G0 phase and do not replicate their DNA or organelles.

What is the difference between asexual and sexual reproduction?

Asexual reproduction involves one parent, while sexual reproduction involves two parents.

What are homologous chromosomes?

Pairs of chromosomes that contain the same genes but potentially different alleles.

Describe what karyotype represents.

A karyotype shows each person has 23 homologous pairs of chromosomes for a total of 46.

What is the difference between haploid and diploid cells?

Haploid cells have half the number of chromosomes, while diploid cells have a full set.

What occurs during Prophase I of meiosis?

Chromosomes are paired with homologous chromosomes, and crossing over occurs.

What is the outcome of cytokinesis in meiosis?

It results in two haploid cells after Telophase I.

How does independent assortment contribute to genetic diversity?

Different genes separate independently during gamete formation.

What are gametes compared to somatic cells?

Gametes are sex cells, whereas somatic cells are body cells.

What is parthenogenesis?

A form of reproduction where non-mammalian females produce offspring without fertilization.

What happens during spermatogenesis?

It produces four sperm cells through meiosis.

What are the stages of cell signaling?

Reception, transduction, and response.

What is the role of secondary messengers in cell signaling?

They provide an alternative pathway for signal transduction.