Cell Division

These flashcards cover key concepts regarding cell division, genomes, mitosis, meiosis, and the significance of sexual reproduction.

Why do unicellular organisms undergo cell division?

For reproduction.

What are the reasons multicellular organisms divide their cells?

To grow, replace old cells, repair damaged tissues, and produce sexual cells (gametes).

What constitutes a cell's genome?

All the DNA in a cell, found in the nucleus.

How many base pairs are in the human genome?

About 3 billion base pairs.

What is a chromosome made of?

DNA tightly packed with proteins, organized as nucleosomes.

What is the difference between haploid and diploid cells?

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

What is the human karyotype?

It consists of 2n, 46 chromosomes (23 pairs).

What happens during prophase of mitosis?

The nuclear membrane dissociates, nucleolus disappears, and chromatids condense.

What is cytokinesis?

The process where the cell's cytoplasm divides, resulting in two separate daughter cells.

What is the purpose of checkpoints in the cell cycle?

To pause or stop the cell cycle when necessary.

What is genetic recombination?

The process during meiosis where crossing over occurs, leading to shuffled genes.

What results from non-disjunction during meiosis?

Gametes with the wrong number of chromosomes, leading to conditions like Down syndrome.

How does sexual reproduction increase genetic variation?

Through genetic recombination, independent assortment, and random fertilization.

What is the main disadvantage of sexual reproduction?

It can be slow, costly, and inefficient.

What are some advantages of sexual reproduction?

Increased genetic diversity and adaptability.