Study Guide DNA Replication, Cell Division and Karyotypes

These flashcards cover key concepts from DNA replication, cell division, and karyotypes, providing a comprehensive review for your exam.

What are the main steps in DNA replication?

The two main steps are the unzipping of the DNA and the complementary base pairing to form new strands.

What is the complementary DNA strand for TCCGGTAA?

AGGCATTT.

What allows cancer cells to continually divide?

Cancer cells evade normal regulatory mechanisms that stop cell division.

What is the minimum number of mutations for a cell to become cancerous?

Typically, it requires several mutations, including changes in oncogenes and tumor suppressor genes.

How do cancer cells differ from normal cells?

Cancer cells divide uncontrollably and can invade other tissues, unlike normal cells which have regulation.

What distinguishes homologous chromosomes from sister chromatids?

Homologous chromosomes are pairs of similar chromosomes, while sister chromatids are identical copies of a single chromosome.

What are the stages of mitosis?

The stages are Prophase, Metaphase, Anaphase, and Telophase.

When does DNA replication occur during the cell cycle?

DNA replication occurs during the S phase of interphase.

What type of cells do not undergo mitosis?

Gametes (sperm and eggs) do not undergo mitosis; they are produced through meiosis.

How many daughter cells does mitosis produce and what is their chromosome number?

Mitosis produces two daughter cells, each with the same number of chromosomes as the parent cell.

How is cytokinesis different in plants vs animals?

In animals, a cleavage furrow forms, whereas in plants, a cell plate forms to divide the cell.

What happens during anaphase I of meiosis?

Homologous chromosomes are pulled apart to opposite poles.

What is the key advantage of sexual reproduction?

It increases genetic variation among offspring.

How is gamete formation in males different from females?

Males produce many small sperm cells, while females produce one large egg cell with most of the cytoplasm.

What is nondisjunction in meiosis?

Nondisjunction occurs when chromosomes fail to separate properly during meiosis, leading to an abnormal number of chromosomes.

Which enzyme unzips DNA during replication?

DNA helicase unzips the DNA.

Which gene prevents a cell from entering mitosis if there are signs of DNA damage?

GRAB is a type of tumor suppressor gene.

What is the result of cancer cells losing anchorage dependence?

It can result in metastasis, allowing cancer cells to spread to other parts of the body.

How does crossing over increase genetic variation?

It allows for the exchange of genetic material between homologous chromosomes during meiosis.

What does a karyotype show?

A karyotype displays the number and appearance of chromosomes in a cell.