AP Bio Unit 4 Review

In what form is DNA loose non-condensed and condense and organized?

non-condensed=chromatin; condensed=chromosome

2 gametes combine to form a _____. What are the 2 gametes?

zygote; sperm and egg

What occurs during anaphase?

sister chromatids separate

What happens when a cell undergoes mitosis but not cytokinesis?

the cell has 2 nuclei

Following (but not including) which phase of the cell cycle do we have 2 sister chromatids?

S phase

This protein is involved in passing cell cycle checkpoints and its concentration will cycle up and down depending on what stage of the cell cycle the cell is in

cyclin

What occurs during the S phase?

DNA synthesis

Mitosis produces what kinds of daughter cells?

2 genetically identical cells with 46 chromosomes

Which checkpoint in the cell cycle is considered the restriction point?

G1 checkpoint

When do chromosomes first become visible in mitosis?

prophase

In both mitosis and meiosis, sister chromatids separate during anaphase, but there are ___ haploid daughter nuclei produced by meiosis compared to ____ diploid nuclei by mitosis

4; 2

What is the period in the cell cycle between divisions?

interphase

When does the nuclear envelope disappear in mitosis?

prophase

Meiosis reduces _____. Fertilization restores _____.

chromosome number

Once mitosis is complete what is the next step?

cytokinesis

When does crossing over occur in Meiosis?

Prophase I

What is a protein that aids in adding a phosphate?

protein kinase

Tetrads of chromosomes are lined up at the equator during which stage of Meiosis?

Metaphase I

Where do chromosomes become visible in Meiosis?

Prophase I and II

At what stage do chromatids separate in Meiosis?

Anaphase II

What kinds of cells are typically in G0?

Nerve, muscle, and liver cells

What is PDGF? What is its purpose?

platelet derived growth factor; stimulates cell division to heal

What connects sister chromatids together?

centromere

How long is the cell cycle of an embryo?

20 minutes

If a cell has 40 chromatids at metaphase, how many chromosomes will ach daughter cell have after cytokinesis?

20

How long is the cell cycle for skin cells?

12-24 hours

In mitosis, which stage do we separate out sister chromatids?

Anaphase

If there are 30 chromatids in a cell, how many centromeres will there be?

15

What is density dependent inhibition?

when cells become overcrowded, they stop dividing

what protein is maintained at constant levels and interacts with cyclin?

cyclin dependent kinases

What are proto-oncogenes?

divide normally, but when mutated they become oncogenes (cancerous cells)

Non-dividing cells are in which stage of the cell cycle?

G0

What happens during a synapse in Meiosis?

homologous chromosomes come together

What is anchorage dependence?

cell must be anchored to something in order to divide

Interphase is composed of which stages of the cell cycle?

G1, S, G2

What is p53? Name on specific role of this gene

tumor repressor gene that plays role in G1/S checkpoint; 3 roles: recruit repair enzymes to repair DNA, triggers apoptosis, and keeps cells in G0 phase

What is the goal of Meiosis II? To separate what?

separate sister chromatids

What is the difference between cytokinesis of animals vs. plant cells?

plant cells form cell plate, animal cells form cleavage furrow

What is the goal of Meiosis I?

separation of homologous chromosomes

How do cells pass the G2 checkpoint?

MPF (allows cells to enter mitosis or M phase); mitosis promoting factor

What phase of the cell cycle does a cell spend most of its life in?

interphase

Cytokinesis is splitting of the ____.

cytoplasm

Once mitosis and cytokinesis are complete, what stage does the cell enter specifically?

G1

What does 2n and n refer to?

2n=diploid (46 chromosomes); n=haploid (23 chromosomes)

List phases of Mitosis in order

Prophase, Metaphase, Anaphase, Telophase, (Cytokinesis)