Bio 189 Test 3- Emily Jackson

same

homo-

color

chrom-

small

micro-

both, double

diplo-

body

-some

single

haplo-

without, lack of, not

a-

to produce

-gen-

chromosomes

ploid

self

auto-

cell

-cyte

end

telo-

before

pro-

between

inter-

many

multi

two

bi

thread

mito-

moving

kin-

one

uni-

segment, body section

-mere

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.

Following DNA replication, each eukaryotic chromosome consists of two identical DNA molecules known as

sister chromatids

Which of the following events occurs during the mitotic phase?

condensation of the chromosomes, separation of sister chromatids, spindle formation

Which statement below best describes a cleavage furrow?

a groove in the plasma membrane between daughter nuclei

Which is the first checkpoint in the cell cycle that will cause a cell to exit the cycle if this point is not passed?

G1

Density-dependent inhibition is explained by which of the following statements?

As cells become more numerous, the cell surface proteins of adjacent cells bind to each other and send signals that inhibit cell division.

What is true of all cancers?

They have escaped normal cell cycle controls.

A _______is a lump of abnormal cells that, although growing out of control, remains at its original site.

benign tumor

A ________is an abnormally growing mass of cells that is actively spreading through the body.

malignant tumor

is the spread of cancer cells from their site of origin to other sites in the body.

metastasis

An individual with a malignant tumor is said to have

cancer

The most common type of cancer is a ________this type always originates in tissues that line organs.

carcinoma

Which of the following components make(s) up eukaryotic chromatin?

DNA and proteins

Somatic cells in golden hamsters have 44 chromosomes. How many chromosomes do their gametes carry?

22

DNA replication produces two identical DNA molecules, called_____ which separate during mitosis.

sister chromatid

After chromosomes condense, the _____ is the region where the identical DNA molecules are most tightly attached to each other.

centromere

During mitosis, microtubules attach to chromosomes at the ___

kinetochore

In dividing cells, most of the cell's growth occurs during _____

interphase

The _____ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division

mitotic spindle

During interphase, most of the nucleus is filled with a complex of DNA and protein in a dispersed form called _____

chromatin

In most eukaryotes, division of the nucleus is followed by, ______when the rest of the cell divides.

cytokinesis

The ______ are the organizing centers for microtubules involved in separating chromosomes during mitosis

centrosome

Study

What must happen before a cell can begin mitosis?

The chromosomes must be duplicated.

The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?

Prophase

The chromosomes line up in the center of the cell during which phase of mitosis?

Metaphase

The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?

Anaphase

The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?

Telophase

At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________.

cytokinesis

A group of cells is assayed for DNA content immediately before beginning mitosis and is found to have an average of 20 picograms of DNA per nucleus. How many picograms of DNA would be found in a cell nucleus following completion of mitosis and cytokinesis?

10

At which phase of mitosis do the sister chromatids become daughter chromosomes?

anaphase

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the mitotic spindle. Which statement below best summarizes the predicted effect of adding colchicine to a sample of cells in G₂?

Chromosomes would condense but fail to align at the metaphase plate, and the cell cycle would arrest at this point.

The data in the table above were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma. Which statement below best describes the delta cells?

They are actually in the G0 phase.

Which statement below best explains why cells from advanced malignant tumors are often found to contain damaged chromosomes as well as abnormal numbers of chromosomes?

Tumor cells are no longer regulated by the checkpoints that normally prevent completion of the cell cycle by cells with chromosome abnormalities.

Which of the following is true of benign tumors but not malignant tumors?

They remain confined to their original site.

Which of these is NOT a carcinogen?

all of the above are carcinogens

_____ is a carcinogen that promotes colon cancer.

Fat