bio unit 7

What is a benign tumor?

A tumor that stays in one place and is less harmful.

What is the difference between malignant and metastatic cancer?

Malignant cancer spreads through the body, while metastatic refers to stage 4 cancer that has spread to other organs.

What are cyclins?

Proteins that regulate and control progression through the cell cycle.

What phases make up interphase?

G1, S, and G2 phases.

What is the main purpose of cell division?

Growth, repair damaged tissue, replace old/dead cells, and reproduction.

What is the difference between sexual and asexual reproduction?

Sexual reproduction involves egg and sperm producing genetically different offspring, while asexual reproduction produces two genetically identical daughter cells.

What are the phases of the cell cycle?

G1 (Gap 1), S (Synthesis), G2 (Gap 2), M (Mitosis + Cytokinesis).

What happens during the S phase of the cell cycle?

DNA replication occurs and chromosomes are copied.

What is the role of checkpoint genes in the cell cycle?

They regulate cell division by acting like 'gas pedals' (proto-oncogenes) and 'brakes' (tumor suppressor genes).

What occurs during the G0 phase?

The cell enters a resting phase, leaves the cycle and stops dividing.

What is semiconservative replication?

Each new DNA molecule has one old strand and one new strand.

What are the base pairing rules for DNA?

A pairs with T, and C pairs with G.

What is the function of helicase during DNA replication?

It unwinds the DNA helix.

Define mitosis.

The division of the nucleus.

What is the primary event during prophase?

Chromosomes condense, the nuclear membrane breaks down, and spindle fibers form.

What distinguishes animal cell cytokinesis from plant cell cytokinesis?

Animal cells form a cleavage furrow while plant cells form a cell plate.

What are the signs of cancer cells?

They divide uncontrollably, ignore checkpoints, and can spread through the body.

What is the end product of DNA replication?

Two identical DNA molecules, each containing one old strand and one new strand.

What is a chromatid?

One half of a duplicated chromosome.

During which phase does the nuclear membrane reform?

Telophase.

What are proto-oncogenes?\n\n

Genes that promote cell division and can become oncogenes when mutated.

What is apoptosis?\n\n

Programmed cell death that eliminates damaged or unnecessary cells.

What is the role of DNA polymerase?\n\n

An enzyme that synthesizes new DNA strands by adding nucleotides.

What are telomeres?\n\n

Repetitive nucleotide sequences at the ends of chromosomes that protect them from degradation.

What distinguishes cancerous cells from normal cells?\n\n

Cancerous cells have uncontrolled growth, evade apoptosis, and can invade surrounding tissues.

What is the function of tumor suppressor genes?\n\n

Genes that inhibit cell division and promote apoptosis to prevent cancer.

How does the environment influence cancer development?\n\n

Factors like radiation, chemicals, and viruses can contribute to mutations that lead to cancer.

What happens during anaphase?\n\n

Sister chromatids are pulled apart to opposite poles of the cell.

What is the function of the spindle apparatus?\n\n

To separate chromosomes during mitosis.

What role do growth factors play in the cell cycle?\n\n

They are signals that stimulate cells to divide.