CHPT 12 CELL DIVISON

What process allows life to continue by producing new cells?

Cell division

What constitutes a cell’s genome?

All the DNA in a cell

How is DNA packaged in the cell?

Chromosomes

How many chromosomes are in human body cells?

46

What are eukaryotic chromosomes made of?

Chromatin (DNA and protein)

What are Somatic Cells?

non reproductive cells (2n)

What are Gamete Cells?

sex cells (n)

How many sets of chromosomes do somatic cells have?

Two sets

How many chromosomes do gametes have?

23

What happens to DNA before cell division?

It is replicated

What are sister chromatids?

Two identical copies of a chromosome

What is the centromere?

The waist where chromatids attach

What are chromatids called once they separate?

Chromosomes

What are the two main parts of eukaryotic cell division?

Mitosis and cytokinesis

How are gametes produced?

By meiosis

How do meiosis and mitosis differ?

Meiosis produces half the chromosomes

What are the two main phases of the cell cycle?

M phase and interphase

What are the three phases of interphase?

G1, G2, S

During which interphase phase are chromosomes duplicated?

S phase

What are the five stages of mitosis?

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

What happens in prophase?

Sister chromatids form

What happens in prometaphase?

Spindle attaches to kinetochores

What happens in metaphase?

Chromosomes line up at the metaphase plate

What happens in anaphase?

Sister chromatids are pulled apart

What happens in telophase?

Nuclear envelopes reform

What is the mitotic spindle made of?

Microtubules

Where does spindle assembly begin?

Centrosome

What is an aster?

A radial array of microtubules

What is a kinetochore?

Site of spindle attachment on centromere

What is cytokinesis?

Division of cytoplasm

What is the cleavage furrow?

The first sign of cytokinesis

What forms during cytokinesis in plant cells?

Cell plate

What type of cell division do prokaryotes use?

Binary fission

Where does DNA replication begin in binary fission?

At the origin of replication

What controls events in the cell cycle?

The cell cycle control system

What are the three main checkpoints in the cell cycle?

G1, G2, M

What is the G0 phase?

Cell stops dividing

How do cancer cells differ from normal cells?

They don’t stop dividing

What is transformation in cancer cells?

When they divide indefinitely

What is a benign tumor?

A tumor that stays in one place

What is a malignant tumor?

A tumor that invades nearby tissues

What is metastasis?

Spread of cancer cells