Cell Division: Mitosis and Meiosis

These flashcards cover key concepts of cell division, focusing on the processes of mitosis and meiosis, their phases, and definitions related to chromosome structure and genetic information.

What is the process by which cells reproduce identical copies of themselves?

Cell division.

What phase of the cell cycle follows G1?

S phase (synthetic phase).

During which phase of the cell cycle does DNA replication occur?

S phase.

What are sister chromatids?

Identical copies of a chromosome that are joined at the centromere.

What term describes the genetic makeup of a cell with two sets of chromosomes?

Diploid.

What term describes a cell that contains only one complete set of chromosomes?

Haploid.

What is the total number of chromosomes in a human somatic cell?

46 chromosomes.

What is the primary type of cell division that occurs in somatic cells?

Mitosis.

What occurs during the G1 phase of the cell cycle?

Cell growth and preparation for DNA replication.

What is karyotype?

A complete set of chromosomes in an organism.

What is the primary function of meiosis?

To reduce the chromosome number from diploid to haploid.

What is the phase of cell division characterized by the alignment of chromosomes along the equatorial plane?

Metaphase.

What do you call the structure formed by homologous chromosomes pairing during meiosis?

Bivalent.

What is the term for chromosomes that differ between males and females?

Sex chromosomes.

What stage of mitosis involves the separation of sister chromatids?

Anaphase.

What happens during telophase of mitosis?

Nuclear envelope reappears and chromosomes begin to decondense.

What is cytokinesis?

The division of the cytoplasm to form two daughter cells.

What type of cells undergo meiosis?

Germ cells (e.g., spermatozoa and oogonia).

In what phase do homologous chromosomes exchange genetic information?

Prophase I during meiosis.

What happens during prophase of mitosis?

Chromosomes condense and become visible, the nuclear envelope disappears.

What is the end result of meiosis?

Four haploid gametes.

Which phase of meiosis is also known as reductional division?

Meiosis I.

What describes cells that have an extra or missing chromosome?

Aneuploid.

How many rounds of division occur in meiosis?

Two rounds: Meiosis I and Meiosis II.

What is the primary event that occurs during metaphase I of meiosis?

Homologous chromosomes align along the metaphase plate.

What is meant by crossing over?

The exchange of genetic material between homologous chromosomes during prophase I.

How do the daughter cells from mitosis compare to the parent cell?

They are genetically identical.

What structure facilitates the separation of chromosomes during mitosis?

The spindle apparatus.

What is the function of telomeres?

To protect chromosome ends from deterioration.

What happens to the nuclear envelope during mitosis?

It breaks down during prophase and reforms during telophase.

What type of chromosomes do humans have 22 pairs of?

Autosomes.

What is the haploid number of chromosomes in humans?

23 chromosomes.

What process immediately follows DNA replication in the cell cycle?

G2 phase.

What is the significance of the synaptonemal complex?

It facilitates the pairing of homologous chromosomes during prophase I.

What happens in anaphase II of meiosis?

Sister chromatids are pulled apart to opposite poles.

What type of cells are produced at the end of meiosis II?

Haploid gametes.

What is the main difference between mitosis and meiosis?

Mitosis results in two identical cells, while meiosis results in four genetically varied gametes.

What is the role of the centromere?

To join sister chromatids together and to attach to the spindle fibers during cell division.

What occurs in pachytene during prophase I of meiosis?

Crossing over occurs between homologous chromosomes.

How long does prophase I last compared to the total duration of meiosis?

It lasts more than 80% of the total duration.

What is a tetrad?

A group of four chromatids formed during prophase I.

What occurs during anaphase of mitosis?

Sister chromatids separate towards opposite ends of the cell.

What does the term 'euploid' refer to?

Cells with complete sets of chromosomes.

What is interphase?

The phase of the cell cycle when the cell is not dividing.

What happens during meiosis II?

Sister chromatids are separated into individual daughter cells.