The Cell Cycle and Cancer

Question 1

Cell Cycle

Answer 1

the period between cell divisions; divided into the phases of interphase, mitosis, and cytokinesis; may also be divided int interphase and M phase (mitosis and cytokinesis)

Question 2

Replication

Answer 2

the copying of the cell’s DNA prior to mitosis so that each daughter cell has an exact copy of the mother cell’s genetic material; results in sister chromatids; occurs in the S phase of interphase

Question 3

Interphase

Answer 3

the longest period of the cell cycle when the cell is actively growing nad metabolizing; consists of G1, S and G2 phases; DNA is in loose, stringy chromatin form not visible under the microscope

Question 4

M phase

Answer 4

mitosis and cytokinesis together

Question 5

Cytokinesis

Answer 5

the phase of the cell cycle after mitosis when the cytoplasm divides into two separate daughter cells. A cleavage furrow forms in animal cells; a division plate forms in plant cells

Question 6

G1 phase

Answer 6

the first part of interphase where the cell is actively growing and undergoing metabolism and protein synthesis

Question 7

S phase

Answer 7

the seocnd part of interphase where DNA replication occurs in preparation for upcoming mitosis; produce sister chromatids

Question 8

G2 phase

Answer 8

the third part of interphasewhere the cell continues growing, metabolizing, and carrying out protein synthesis

Question 9

Sister chromatids

Answer 9

two pieces of DNA that are identical to each other as a result of DNA replication in S phase; lie side by side and are buttoned together by a centromere; together make up one chromosome

Question 10

Eukaryotic cell

Answer 10

a cell with membrane-bound organelles and nucleus

Question 11

Spindle apparatus

Answer 11

a structure composed of spindle fibres; forms during prophase in mitosis to facilitate separation and movement of chromosomes in cell division

Question 12

Desity-dependetn inhibition

Answer 12

a property of normal cells that allows mitosis to occur only until cells touch each other. Density-dependent inhibition is lost in cancer cells; therefore, cells begin to form on top of one another, forming masses of cells called tumours

Question 13

Anchorage dependence

Answer 13

a property of normal cells that only allows mitosis to occur when the cells are attached to a substrate of surface, not floating freely. Anchorage dependence is lost in cancer cells, thereby allowing for metastasis to occur

Question 14

Cancer

Answer 14

rapid proliferation (cell division) of cells that occurs when mutations result in disruption of the normal timing of mitosis; characterized by loss of density-dependent inhibition, loss of anchorage dependence, differentiation of cell function, rapid metabolism, and short cell cycle

Question 15

Metastasis

Answer 15

the tendency of some cancer cells to break off form a primary tumour and move through the blood or lymphatic systems to other locations in the body where secondary tumours form; sometimes referred to as the “spreading” of cancer

Question 16

Radiation treatment

Answer 16

cancer treatment in which high energy radiation from radioactive isotopes is directed at a cancerous tumour in an effort to destroy it without destroying surrounding normal tissue

Question 17

Mutagenic agent

Answer 17

a chemical or physical agent that has the ability to mutate DNA, affecting the timing of the cel cycle; increasing the rate of mitosis

Question 18

Cellular clock

Answer 18

a property of cells that allows them to go through a set number of cell divisions and then stop, whereupon the cell line dies out; sometimes called apoptosis. Cancer cells do not have a normal cell clock so they do not apoptosis

Question 19

Chemotherapy

Answer 19

the use of cytotoxic drugs that inhibit cell division, usually by preventing DNA replication or interfering with the spindle mechanism of mitosis or by interfering with the supply of blood and nutrients to the tumour; applied systemically (into the bloodstream); targets cancerous cells but may also effect rapidly dividing normal cells to some degree

Question 20

Hodgkin’s disease

Answer 20

a blood cancer of lymph tissue