genetics week 1 extra Introduction to Chromosome Structure, the Cell Cycle, and Meiotic Variation

What is a telomere?

Telomeres are the protective caps at the end of chromosomes that help secure genetic material and prevent degradation.

What structure do telomeres form?

Telomeres create a structure called a t-loop, which is composed of telomeric repeats.

What is the function of centromeres?

Centromeres are essential for tracking the movement of chromosomes during mitosis.

What are metacentric chromosomes?

Metacentric chromosomes have a centromere located in the direct middle.

Define homologous chromosomes.

Homologous chromosomes are pairs that have the same size, centromere position, and carry the same genes at identical loci.

What happens in anaphase of mitosis?

In anaphase, sister chromatids attached by the centromeres are pulled apart.

What is the primary difference between mitosis and meiosis?

Mitosis produces two identical daughter cells, while meiosis produces four non-identical haploid daughter cells.

What is crossing over?

Crossing over occurs during Meiosis I when homologous chromosomes exchange genetic information, leading to genetic variation.

How many telomeres are present during G2 if a cell has 22 metacentric chromosomes?

There are 88 telomeres present during G2 because each chromosome has four telomeres after DNA replication.

What is the importance of the S phase of the cell cycle?

During the

What is a telomere?

A telomere is a repetitive DNA sequence at the end of a chromosome that helps protect the genetic material, forming a structure known as a t-loop.

What is the function of telomeres?

Telomeres prevent chromosome degradation and fusion by protecting the ends of chromosomes.

What are the four types of chromosomes based on centromere position?

1. Metacentric - centromere in the middle; 2. Submetacentric - centromere off-center; 3. Acrocentric - centromere near telomeres; 4. Telocentric - centromere close to telomere, short arms barely visible.

What is the difference between diploid and haploid cells?

Diploid cells (2n) have two sets of chromosomes, while haploid cells (n) have one set.

How many telomeres are present in a somatic cell with 22 chromosomes during G2?

There are 88 telomeres in G2, as each replicated chromosome has 4 telomeres (2 chromatids x 2 telomeres each).

What is the significance of crossing over during meiosis?

Crossing over increases genetic diversity by exchanging genetic material between non-sister chromatids.

Define homologous chromosomes.

Homologous chromosomes are pairs of chromosomes that have the same size, centromere position, and carry the same genes at the same loci, though they may have different alleles.

What are the stages of mitosis?

The stages of mitosis are Prophase, Prometaphase, Metaphase, Anaphase, and Telophase.

What happens to sister chromatids during anaphase?

During anaphase, sister chromatids are separated and pulled apart toward opposite poles of the cell.

What is the role of the centromere?

The centromere is a region of the chromosome that holds sister chromatids together and is crucial for chromosome segregation during cell division.