Chapter 8

Question 1

Asexual reproduction

Answer 1

the creation of genetically identical offspring by a single parent. no gametes

Question 2

Cell divisions results in a whole new..

Answer 2

single celled organism

Question 3

Single celled organisms reproduce ..

Answer 3

asexually

Question 4

Sexual reproduction

Answer 4

fertilization of gametes resulting in offspring not identical to parents but contributes to genetic diversity

Question 5

Meiosis

Answer 5

cell divides produces gametes

Question 6

Mitosis

Answer 6

cell divine enables sexually reproducing individuals to grow from a single fertilized egg

Question 7

Binary fission

Answer 7

two identical cells arise from one cell dividing in half

Question 8

Steps in binary fission

Answer 8

• chromosome duplicates
• cell elongates, chromosomal copies separate fourth
• plasma membrane grows inward at the midpoint to divide the cells

Question 9

Eukaryotic cells are composed of..

Answer 9

chromatin

Question 10

Chromatin

Answer 10

dna and protiens

Question 11

Each chromosome appears as..

Answer 11

two sister chromatids, containing identical DNA molecules

Question 12

Centromere

Answer 12

sister chromatids joined at this narrow region

Question 13

1 human has __ chromosomes

Answer 13

46

Question 14

2 stages of the cell cycle

Answer 14

inter phase and mitotic phase

Question 15

Interphase

Answer 15

duplication of cell contents

Question 16

3 phases of interphase

Answer 16

G1, S, G2

Question 17

G1 phase

Answer 17

growth increase in cytoplasm

Question 18

G2 phase

Answer 18

growth, preparation for division

Question 19

S phase

Answer 19

duplication of chromosomes

Question 20

Mitotic phase

Answer 20

divison

Question 21

2 phases of mitotic phase

Answer 21

mitosis and cytokinesis

Question 22

Mitosis

Answer 22

division of the nucleus

Question 23

Cytokinesis

Answer 23

division of cytoplasm

Question 24

5 stages of mitosis

Answer 24

• prophase
• prometaphase
• metaphase
• anaphase
• telophase

Question 25

Cytokinesis often over laps...

Answer 25

telophase

Question 26

What occurs in interphase

Answer 26

cytoplasmic contents double, 2 centrosomes form, chromosomes duplicate in the nucleus during S phase, nucleoli sites ribosomes assemble

Question 27

What occurs in the cytoplasm in prophase

Answer 27

microtubules begin to emerge from centrosome foreign the mitotic spindle

Question 28

What occurs in the nucleus

Answer 28

chromosomes coil and become compact and nucleoli disappear

Question 29

What occurs in prometaphase

Answer 29

mitotic spindles from each pole attach to each sister chromatid pair, chromosomes moved to centre of cell and nuclear membrane breaks down

Question 30

What occurs in metaphase

Answer 30

mitotic spindle fully formed, the chromosomes align at cell equator, kinetochores of sister chromatids are facing opposite poles of the spindle

Question 31

What occurs in anaphase

Answer 31

sister chromatids are pulled apart, daughter chromosomes are moved to opposite poles of cell and the cell elongates

Question 32

What occurs in telophase

Answer 32

the cell continues to elongate , the nuclear envelope forms around chromosomes at each pole (establishing each daughter cell), the chromatin uncoils and nucleoli reappear, spindle disappear

Question 33

Cleavage furrow forms from..

Answer 33

contracting ring of microtubules interacting w/ myosin

Question 34

Cleavage furrow

Answer 34

depends to separate contents into two cells

Question 35

cell cycle control system

Answer 35

set of molecules in the cell that triggers and coordinates key events in the cell cycle

Question 36

Check points in the cell cycle are

Answer 36

G1, G2, M

Question 37

Benign tumours

Answer 37

remain at original site

Question 38

Malignant tumours

Answer 38

spread to other tissues

Question 39

Carcinomas arise from

Answer 39

internal/external body coverings (ducts)

Question 40

Sarcomas arise from

Answer 40

supportive/connective tissue (bone)

Question 41

Locus/loci

Answer 41

position of gene

Question 42

Meiosis 1

Answer 42

homologous chromosomes separate

Question 43

Meiosis 11

Answer 43

sister chromatids separate

Question 44

Tetrad

Answer 44

4 chromatids

Question 45

Crossing over occurs in..

Answer 45

Prophase 1

Question 46

3 processes create new combinations of genetic info

Answer 46

- independent orientation - random fertilization - crossing over

Question 47

Nondisjunction

Answer 47

failure of chromosomes to separate normally during meiosis

Question 48

Rearrangements in chromosomes may include

Answer 48

- deletion - duplication - inversion - transloaction