The Cell Cycle, Mitosis, Meiosis

These flashcards cover key concepts related to the cell cycle, mitosis, and meiosis based on the lecture notes.

What are gametes and how many chromosomes do they have?

Gametes are reproductive cells (ova and sperm) that have 23 different chromosomes and are haploid (n).

What are somatic cells?

Somatic cells include all body cells except those undergoing or resulting from meiosis.

What is the chromosome number in somatic cells?

Somatic cells have 46 chromosomes and are diploid (2n), composed of 23 homologous pairs.

What are homologous chromosomes?

Homologous chromosomes are a pair of chromosomes (one from each parent) that are similar in length, centromere position, and have genes for the same traits.

What is a gene?

A gene is a unit of heredity, a region of DNA that contains information for synthesizing a protein.

What is the purpose of the cell cycle?

The cell cycle is for the growth and repair of tissues.

What are the main stages of the cell cycle?

The main stages of the cell cycle are Interphase and Mitotic (M) phase.

What happens during the S phase of interphase?

During the S phase, chromosomes replicate, forming sister chromatids.

What occurs during prophase in mitosis?

In prophase, chromosomes condense and become visible, nucleoli disappear, and the nuclear envelope breaks down.

What is cytokinesis?

Cytokinesis is the division of the cytoplasm that occurs at the end of mitosis.

What is meiosis and what does it produce?

Meiosis is a type of cell division that produces gametes (ova and sperm), resulting in four genetically unique haploid cells.

What distinguishes meiosis I from mitosis?

Meiosis I is a reduction division where homologous chromosomes separate, reducing the chromosome number from diploid (2n) to haploid (n).

What happens during telophase II in meiosis?

During telophase II, chromosomes uncoil to form chromatin, the nucleoli and nuclear envelope reappear, and cytokinesis occurs, resulting in four haploid cells.

Why is meiosis important for sexual reproduction?

Meiosis is important because it produces haploid gametes that combine during fertilization to form a diploid zygote.