Cell Division - BIO Lab Exam 3

What happens in G1 of Interphase?

Cell grows and performs normal functions.

What happens in S phase of Interphase?

DNA replication occurs; chromosomes become duplicated.

What happens in G2 of Interphase?

Organelles replicate; cell prepares for division.

What is the purpose of checkpoints in Interphase?

They ensure DNA is intact, replicated correctly, and prevent faulty cells from dividing.

What is the order of the stages of Mitosis?

Prophase, Metaphase, Anaphase, Telophase (then Cytokinesis).

What happens in Prophase?

Chromosomes condense, nuclear envelope breaks down, spindle forms.

What happens in Metaphase?

Chromosomes line up in the middle of the cell.

What happens in Anaphase?

Sister chromatids separate and move to opposite poles.

What happens in Telophase?

Nuclear envelopes reform and chromosomes uncoil.

What happens in Cytokinesis?

Cytoplasm divides into two identical daughter cells.

How do you recognize Prophase under a microscope?

Chromosomes appear condensed; nucleus disappears.

How do you recognize Metaphase under a microscope?

Chromosomes line up across the middle.

How do you recognize Anaphase under a microscope?

Sister chromatids pulled apart, forming V shapes.

How do you recognize Telophase under a microscope?

Two nuclei forming.

Which cells undergo Mitosis?

Somatic (body) cells.

Which cells undergo Meiosis?

Germ cells in ovaries/testes that produce gametes.

What is the chromosome state at the start of Mitosis?

Diploid, duplicated chromosomes.

What is the chromosome state at the end of Mitosis?

Diploid, unduplicated chromosomes.

What is the chromosome state at the start of Meiosis I?

Diploid, duplicated chromosomes in homologous pairs.

What is the chromosome state at the end of Meiosis I?

Haploid, duplicated chromosomes.

What is the chromosome state at the end of Meiosis II?

Haploid, unduplicated chromosomes.

What events introduce genetic diversity in Meiosis?

Crossing over (Prophase I) and independent assortment (Metaphase I).

When does crossing over occur?

Prophase I.

When does independent assortment occur?

Metaphase I.

How is the sex of the offspring determined?

By the sperm's chromosome (X or Y).

How many functioning sperm come from one spermatocyte?

Four.

What chromosomes can sperm have?

X or Y.

How many functioning eggs come from one oocyte?

One.

What chromosome do eggs have?

X only.