Honors Cell Division Review Questions

What happens to the surface area to volume ratio as a cell becomes too large?

The surface area to volume ratio decreases as the cell becomes too large.

Why is a decreasing surface area to volume ratio a problem for transport across the cell membrane?

Because nutrients can't go in and out efficiently.

What DNA related problems arise from a cell that is too large?

Information overload and longer time for DNA to reach other parts of the cell.

What occurs in a cell before mitosis that ensures a full set of chromosomes in each new cell? When does this happen?

DNA replication occurs during the S phase of interphase.

What do sister chromatids ensure during mitosis?

That each of the two new daughter cells receives a full complement of 46 chromosomes.

What is chromatin and when does DNA take this form?

Loose uncoiled DNA during Interphase.

What are the characteristics of a chromatid?

Identical halves of a duplicated x-shaped chromosome.

What are sister chromatids?

Exact copies of a chromosome that are linked by a centromere.

When are chromosomes highly condensed during cell division?

During prophase and metaphase.

What are homologous chromosomes? When are they found?

A pair of chromosomes that code for the same traits but are not identical; found during Meiosis 1.

What happens during prophase of mitosis?

Genetic material condenses, showing duplicated chromosomes, and spindle fibers form.

What happens during metaphase of mitosis?

Centromeres line up across the center of the cell.

What happens during anaphase of mitosis?

Chromosomes separate and move to opposite sides of the cell.

What happens during telophase of mitosis?

Chromosomes spread out and spindle fibers break apart.

What type of proteins control the cell cycle? What occurs when a cell loses control of the cell cycle?

Regulatory proteins control the cell cycle; cancer occurs when a cell divides too rapidly.

What is the mass of cells formed by cancer called?

A tumor.

Is cancer caused by a single genetic mutation?

No, cancer is not caused by a single genetic mutation.

What are the differences between sister chromatids and homologous chromosomes?

Sister chromatids are exact copies of a chromosome, while homologous chromosomes are a pair that code for the same traits but are not identical.

What are gonads, and what do they produce? Give examples.

Gonads are organs (testes or ovaries in animals, petals in plants) that produce gametes (sperm and eggs).

What is the difference between body cells and gametes in terms of chromosome number?

Body cells are diploid (2n), while gametes are haploid (n).

Why are sperm and egg cells haploid?

To ensure that when they fuse during fertilization, the resulting embryo has the correct total amount of DNA (46).

What are stem cells special for?

They can self-renew and differentiate into specialized cell types.

What are the three levels of stem cells?

Totipotent, pluripotent, and multipotent, differentiated by their potency.

Give examples of medical treatments that incorporate stem cells.

Regeneration of damaged tissues and bone marrow transplants.

What is crossing over and when does it occur?

The exchange of DNA segments among homologous chromosomes during prophase 1 of meiosis.

What implications does non-disjunction in meiosis have?

It leads to widespread impacts as every offspring cell could have abnormal chromosomes.

What is the information at a location on a chromosome called?

allele