Ch 8A Mitosis and the Cell Cycle Homework

Nucleoli are present during _____.

Nucleoli are present during interphase.

DNA and histone proteins

Nucleosomes are made of

Did doctors ask Henrietta Lacks' permission to take her cells, and was she paid for them?

She was never told that her cells were being taken, and neither she nor her family has been compensated.

Chromatin consists of ______.

DNA and protein

Cells taken from Henrietta Lacks have been used for experiments leading to _____.

-new treatments for cancer -the development of a polio vaccine -tests of the effects of atomic radiation on life

With the exception of gametes a human cell contains ________ chromosomes

46

plant cells form a cell plate and animal cells do not

As shown in the accompanying figure plant cell cytokinesis differes from animal cell cytokinesis because _______

How did doctors harvest and culture cells from Henrietta Lacks?

Cells were taken while she was being treated for cancer many years ago, and these cells have been cultured in the lab ever since.

metastasis

The spread of cancer cells beyond their original site

What property of Henrietta Lacks' cells was most unusual when they were grown in the laboratory?

They continue to divide and multiply after decades of culture.

-Reducing risk factors might decrease the number of cancer cases, but would be unlikely to decrease the cancer deadliness percentages - The combined survivability of all types of cancer is about 65%

What statements are true Dividing the number of deaths by the number of cases per year gives a good estimate of the deadliness of each cancer. For lung cancer, dividing 159,000 deaths by 224,000 cases and multiplying by 100 reveals that lung cancer is 71% deadly. Similarly, breast cancer is 17% deadly and prostate cancer is 13% deadly.

lung, breast, prostate

You can estimate the deadliness of each type of cancer by dividing the number of deaths by the number of cases. If nearly everyone who received a diagnosis of one particular type of cancer dies, the ratio will be near 1 (or 100% deadly). If many more people receive a diagnosis than die, the ratio will be near 0 (or 0% deadly). Rank these three cancer types from the most deadly to the least deadly.

centromeres divide and sister chromatids become full- fledged chromosomes during ______.

anaphase (sister chromatids seperate and migrate to opposite poles)

the structure where sister chromatids are joined is called the

centromere

A _______ is a protein that promotes cell division. In excess, such a protein may lead to cancer

growth factor

During _____ the cell grows and replicates both its organelles and its chromosomes.

interphase

Eukarotic cells have their chromosomes packaged in the ______.

nucleus

A gene that causes a cell to become cancerous is called a

oncogene

Spindle fibers attach to kinetochores during _____.

prometaphase

Chromosomes become visible during _____.

prophase

The correct sequence of stages of mitosis is ______.

prophase, metaphase, anaphase, telophase

a normal gene that if mutated can lead to cancer is called

proto-oncogene

A duplicated chromosome consists of two ______.

sister chromatids

which event occurs during anaphase

sister chromatids become separate chromosomes

When cells were first taken from Henrietta Lacks, she was _____.

suffering from cervical cancer

Cytokinesis often, but not always, accompanies _____.

telophase

When referring to cell division, oncogenes are most like _____ while tumor supressor genes are most like______

the gas pedal pedal on a car; the brakes on a car

During _____ both the contents of the nucleus and the cytoplasm are divided.

the mitotic phase

A(n) _________ is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous.

tumor-suppressor gene

During prophase a homologous pair of chromosomes consists of _____.

two chromosomes and four chromatids

E

which of these phases encompasses all of the stages of mitosis