Chp 9 - Cell cycle

All about the cell cycle - Mitosis, interphase, G1 phase, S phase, G2 phase, etc.

What is the chromatin made up of?

DNA and proteins

Humans produce skin cells by mitosis and gametes by meiosis. Which of the following statements about the nuclei of skin cells is correct?

They contain twice as much DNA as the nuclei of gametes produced by meiosis.

What event is the beginning of anaphase indicated by?

enzymatic cleavage of cohesin

Define cohesin

specific proteins that hold sister chromatids together in the middle (centromere)

At which phase of mitosis does the sister chromatids become daughter chromosomes

anaphase

Define a cleavage furrow

groove in the plasma membrane between daughter nuclei

during which phase of mitosis do centrioles begin to move apart?

prophase

Where are the motor proteins that move chromosomes toward the poles of the mitotic spindle located?

on the kinetochores & at the centrosomes

What makes up eukaryotic chromatin

DNA & protein

Following DNA replication, each chromosomes consists of 2 identical DNA molecules known as: ________

sister chromatids

what are microtubules made up of and what is their function?

made up of subunits of tubulin and are structures in which substances are transported in the cell.

What does phosphorylation do?

Changes the shape of the protein

The complex of DNA and protein that makes up a eukaryotic chromosome is properly called

chromatin

The cleavage furrow forms during which stage of mitosis and cell division of an animal cell?

cytokinesis

A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in the cells doubled __________.

Between G1 and G2 phase

Tissue culture experiments with PDGF demonstrate that without this substance __________

fibroblasts fail to divide

What is the difference between a benign tumor and a malignant tumor?

Cells of benign tumors do not metastasize; those of malignant tumors do.

One event occurring during prophase is __________.

the beginning of the forming of the mitotic spindle

During interphase, the genetic material of a typical eukaryotic cell is __________.

dispersed in the nucleus as long strands of chromatin

The person credited with the axiom, “Every cell from a cell” is __________.

Rudolf Virchow

During binary fission of a bacterium, __________.

origins of replication move apart

Define chromatids?

The double of chromosomes.

Why is it difficult to observe individual chromosomes with a light microscope during interphase?

Because during interphase the chromosomes aren’t condensed yet

Examples of carcinogens

fats, UV light, testosterone, cigarette smoke