Ch 8 Cellular Reproduction

Question 1

reproduction

Answer 1

• may result in the birth of new organisms

- more commonly involves the production of new cells

Question 2

cell division

Answer 2

cellular reproduction

Question 3

chromosomes

Answer 3

the structures that contain most f the cells DNA

Question 4

asexual reproduction

Answer 4

• single celled organisms can reproduce by simple cell division
• there is no fertilization of an egg by a sperm

Question 5

example of asexual reproduction

Answer 5

• growing a new plant from a plant clipping

- sea stars reproducing

Question 6

in asexual reproduction

Answer 6

the lone parent and its offspring have identical genes

Question 7

mitosis is the type of cell division responsible for

Answer 7

• asexual reproduction

- growth and maintenance of multicellular organisms

Question 8

sexual reproduction requires

Answer 8

fertilization of an egg by a sperm

Question 9

sister chromatids

Answer 9

before a cell divides it duplicates all of its chromosomes, resulting in two copies of identical genes

Question 10

centromere

Answer 10

where two sister chromatids are joined together tightly at a narrow “waist”

Question 11

when sister chromatids are separated

Answer 11

each chromatid

• is considered a full-fledged chromosome and
• identical to the original chromosome

Question 12

a cell cycle is the ordered sequence of events that extend

Answer 12

• from the time a cell is first formed from a dividing parent cell
• to its own division into two cells

Question 13

the cell cycle consists of two distinct phases

Answer 13

1. interphase

2. the mitotic phase

Question 14

interphase

Answer 14

-performs its normal functions
-doubles everything in its cytoplasm
grows in size

Question 15

mitotic phase

Answer 15

1. mitosis in which the nucleus and its contents divide evenly into two daughter nuclei and
2. cytokinesis in which the cytoplasm is divided in two

Question 16

what is cancer

Answer 16

a disease of the cell cycle

-cancer cells do not respond normally to the cell cycle control system

Question 17

tumors

Answer 17

-can be caused by cancer cells, abnormally growing masses of body cells

Question 18

benign tumor

Answer 18

if the abnormal cells remain in the original site

Question 19

metastasis

Answer 19

the spread of cancer from its original site

Question 20

malignant tumors

Answer 20

• spread to other parts of the body

- interrupt normal body functions

Question 21

cancer treatments

Answer 21

1. radiation, which damages DNA and disrupts cell division

2. chemotherapy, which is the use of drugs to disrupt cell division

Question 22

behaviors that decrease risk of cancer

Answer 22

• not smoking
• exercising adequately
• moderate exposure to the sun
• eating a high fiber diet
• perfomring self exams
• regular doctors visits

Question 23

sexual reproduction

Answer 23

• depends on meiosis and fertilization

- produces offspring that contain a unique combination of genes from the parents

Question 24

life cycle

Answer 24

the sequence of stages leading from the adults of one generation to the adults of the next

Question 25

humans are diploid organisms with

Answer 25

• body cells containing two sets of chromosomes

- haploid gametes that have only one member of each homologous pair of chromosomes

Question 26

in meiosis

Answer 26

• four haploid daughter cells are produced in diploid organisms
• interphase is followed by two consecutive divisions, meiosis 1 and meiosis 2

Question 27

mitosis uses one division to produce

Answer 27

two diploid cells

Question 28

meiosis uses two divisions to produce

Answer 28

four haploid cells

Question 29

independent assortment

Answer 29

the aligned during metaphase 1 of meiosis, the side-by-side orientation of chromosomes is a matter of chance

Question 30

crossing over

Answer 30

swapping DNA

Question 31

nondisjunction

Answer 31

• the members of a chromosome pair fail to separate at anaphase
• producing gametes with an incorrect number of chromosomes

Question 32

if an organism survives nondisjunction

Answer 32

• it will have an abnormal karyotype

- and probably a syndrome of disorders caused by the abnormal number of gametes

Question 33

down syndrome

Answer 33

• trisomy 21
• a condition in which an individual has an extra chromosome 21
• affects about one out of every 700 children

Question 34

asexual reproduction creates

Answer 34

• genetically identical offspring

- conveys an evolutionary advantage when organisms are suited to a stable environment

Question 35

sexual reproduction may convey an evolutionary advantage by

Answer 35

• creating diversity within a population

- speeding adaptation to a changing environment