2nd Cell Cycle, Mitosis, Meiosis, Karyotypes

What are the phases of the Cell Cycle?

The phases of the Cell Cycle are G1 (Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitosis).

What events occur during the G1 Phase?

In the G1 Phase, the cell grows, carries out normal functions, and prepares for DNA replication.

What happens during the S Phase?

In the S Phase, DNA replication occurs, resulting in each chromosome being copied into sister chromatids.

What is the purpose of the G2 Phase?

During the G2 Phase, the cell continues to grow and prepares for mitosis by producing necessary proteins and enzymes.

Describe the events of the M Phase.

The M Phase involves mitosis (division of the nucleus) and cytokinesis (division of the cytoplasm).

What is the relative length of each phase in the Cell Cycle?

G1 is the longest phase, S is of moderate length, G2 is short, and M is very short.

What are the types of cells involved in Mitosis?

Mitosis occurs in somatic (body) cells.

What are the phases of Mitosis?

The phases of Mitosis are Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis.

What occurs during Prophase in Mitosis?

In Prophase, chromatin condenses into visible chromosomes, the nuclear membrane breaks down, and spindle fibers begin to form.

What happens during Metaphase in Mitosis?

During Metaphase, chromosomes line up at the cell's equator and spindle fibers attach to their centromeres.

Describe the events of Anaphase in Mitosis.

Anaphase is when sister chromatids separate and move toward opposite poles of the cell.

What occurs during Telophase in Mitosis?

In Telophase, nuclear membranes reform around each set of chromosomes, which then uncoil back into chromatin.

What are the products of Mitosis?

Mitosis produces 2 diploid (2n) cells that are genetically identical to the parent cell.

How does cytokinesis differ in plant and animal cells?

In animal cells, cytokinesis forms a cleavage furrow that pinches the cell, while in plant cells, a cell plate forms that develops into a new cell wall.

What types of cells undergo Meiosis?

Meiosis occurs in germ cells, which produce gametes.

What are the phases of Meiosis I?

The phases of Meiosis I are Prophase I, Metaphase I, Anaphase I, and Telophase I followed by cytokinesis.

What events occur during Prophase I of Meiosis?

During Prophase I, chromosomes condense, homologous chromosomes undergo synapsis, and crossing over occurs.

Describe the events of Metaphase I in Meiosis.

In Metaphase I, homologous pairs align at the equator of the cell, and independent assortment occurs.

What happens during Anaphase I in Meiosis?

Anaphase I involves the separation of homologous chromosomes to opposite poles.

What are the products of Meiosis I?

Meiosis I results in the formation of two haploid (n) cells that still have duplicated chromosomes.

What are the phases of Meiosis II?

The phases of Meiosis II are Prophase II, Metaphase II, Anaphase II, Telophase II, and cytokinesis leading to four haploid cells.

What events occur during each phase of Meiosis II?

In Meiosis II, Prophase II involves chromosome condensation; Metaphase II sees chromosomes line up at the equator; Anaphase II has sister chromatids separating; Telophase II reforms nuclear membranes.

What are the products of Meiosis II?

Meiosis II produces a total of four haploid (n) cells that are genetically unique due to crossing over and independent assortment.

What is a karyotype and how is it organized?

A karyotype is a display of all chromosomes in a cell arranged by size and shape.

What are sex chromosomes and their significance?

Sex chromosomes determine biological sex, with XX representing female and XY representing male.

What is monosomy?

Monosomy refers to the condition of having one less chromosome, such as in Turner syndrome with the genotype XO.

What is trisomy?

Trisomy is a condition where there is an extra chromosome, exemplified by Down syndrome, which is Trisomy 21.

Define haploid and diploid cells.

Haploid (n) cells have one set of chromosomes, while diploid (2n) cells have two sets.

What is crossing over and where does it occur?

Crossing over is the exchange of genetic material between homologous chromosomes, which occurs during Prophase I of Meiosis.

What is synapsis?

Synapsis is the pairing of homologous chromosomes during Prophase I of Meiosis.

What is a gamete?

A gamete is a sex cell, either sperm or egg.

What is a zygote?

A zygote is a fertilized egg formed from the fusion of two gametes.

What is a somatic cell?

A somatic cell is a body cell that undergoes mitosis.

What is chromatin?

Chromatin is uncoiled DNA and proteins present in the nucleus.

Define chromatid.

A chromatid is one half of a duplicated chromosome.

What is a chromosome?

A chromosome is a condensed DNA molecule containing genetic information.

What is the relationship between Mitosis and Meiosis regarding genetic variation?

Mitosis produces genetically identical cells, while Meiosis produces genetically unique cells due to crossing over and independent assortment.