Chapter 2

Question 1

Prokaryote

Answer 1

unicellular organism with a relatively simple cell structure; includes bacteria and archaea

Question 2

Eukaryote

Answer 2

organism that has a compartmentalized cell structure, including a nuclear envelope and membrane-bound organelles; can be uni or multicellular

Question 3

Histone

Answer 3

protein found in eukaryotes that associate closely with DNA to form chromosomes

Question 4

Chromatin

Answer 4

material found in the eukaryotic nucleus; consists of DNA and histone proteins

Question 5

For successful cell reproduction:

Answer 5

its genetic information must be copies, the copies must be separated from each other, the cell must divide

Question 6

Diploid

Answer 6

possessing two sets of chromosomes (two genomes)

Question 7

Haploid

Answer 7

possessing a single set of chromosomes (one genome)

Question 8

Centromere

Answer 8

serves as the attachment point for spindle microtubules

Question 9

Telomeres

Answer 9

specific DNA sequences and associated proteins located at the tips of whole linear chromosomes

Question 10

Origin of Replication

Answer 10

site where DNA replication is initiated

Question 11

Sister Chromatids

Answer 11

two copies of a chromosomes that are held together at the centromere; each sister chromatid consists of a single molecule of DNA

Question 12

G naught phase

Answer 12

stable, nondividing period of variable length

Question 13

G1 phase

Answer 13

growth and development of the cell

Question 14

S phase

Answer 14

synthesis of DNA

Question 15

G2

Answer 15

preparation for division

Question 16

Prophase

Answer 16

chromosomes condense, and mitotic spindle forms

Question 17

Prometaphase

Answer 17

nuclear membrane disintegrates, and spindle microtubules anchor to kinetochores

Question 18

Metaphase

Answer 18

chromosomes align on the metaphase plate; spindle-assembly checkpoint

Question 19

Anaphase

Answer 19

sister chromatids separate, becoming individual chromosomes that migrate toward spindle poles

Question 20

Telophase

Answer 20

chromosomes arrive at spindle poles, the nuclear membrane re-forms, and the condenses chromosomes relax

Question 21

Cytokinesis

Answer 21

cytoplasm divides; cell wall forms in plant cells

Question 22

Synapsis

Answer 22

the fusion of chromosome pairs at the start of meiosis

Question 23

Tetrad

Answer 23

a homologous pair of synapsed chromosomes consisting of four chromosomes

Question 24

Crossing Over

Answer 24

exchange of genetic material between homologous but nonsister chromotids

Question 25

Prophase I

Answer 25

chromosomes condense, homologous chromosomes synapse, crossing over takes places, the nuclear membrane breaks down, and the mitotic spindle forms

Question 26

Metaphase I

Answer 26

homologous pairs of chromosomes line up on the metaphase plate

Question 27

Anaphase I

Answer 27

the two chromosomes of a homologous pair separate and move toward opposite poles

Question 28

Telophase I

Answer 28

chromosomes arrive at the spindle poles

Question 29

Cytokinesis

Answer 29

the cytoplasm divides to produce two cells, each having half the original number of chromosomes

Question 30

Interkinesis

Answer 30

in some types of cells, the spindle breaks down, chromosomes relax, and a nuclear membrane reforms, but no DNA synthesis takes place

Question 31

Prophase II

Answer 31

chromosomes recondense, the spindle reforms, and the nuclear membrane disintegrates

Question 32

Metaphase II

Answer 32

individual chromosomes line up on the metaphase plate

Question 33

Anaphase II

Answer 33

sister chromatids separate and move as individual chromosomes toward opposite spindle poles

Question 34

Telophase II

Answer 34

chromosomes arrive at the spindle poles; the spindle breaks down and a nuclear membrane reforms

Question 35

Cytokinesis

Answer 35

the cytoplasm divides

Question 36

Recombination

Answer 36

process that produces new combinations of alleles

Question 37

Spermatogenesis

Answer 37

production of gametes in a male animal; takes place in the testes

Question 38

Spermatogonia

Answer 38

diploid cell in the testis; capable of undergoing meiosis to produce a sperm

Question 39

Primary Spermatocyte

Answer 39

spermatogonium that has entered prophase I

Question 40

Secondary Spermatocyte

Answer 40

product of meiosis I in male animals

Question 41

Spermatid

Answer 41

immediate product of meiosis II in spermatogenesis; matures to sperm

Question 42

Oogenesis

Answer 42

the products of gametes in a female animal

Question 43

Oogonia

Answer 43

diploid cell in the ovary; capable of undergoing meiosis to produce an egg cell

Question 44

Primary Oocyte

Answer 44

oogonium that has entered prophase I

Question 45

Secondary Oocyte

Answer 45

one of the products of meiosis I in oogenesis; receives most the cytoplasm

Question 46

First Polar Body

Answer 46

one of the products of meiosis I in oogenesis; the smaller cell, which contains half the chromosomes but only a small part of the cytoplasm

Question 47

Ovum

Answer 47

the mature female gamete

Question 48

Second Polar Body

Answer 48

one of the products of meiosis II in oogenesis; contains a set of chromosomes but little of the cytoplasm

Question 49

Microsporocyte

Answer 49

diploid reproductive cell in the stamen of a plant; undergoes meiosis to produce four haploid microspores

Question 50

Microspore

Answer 50

haploid product of meiosis in plants

Question 51

Megasporocyte

Answer 51

diploid reproductive cell in the ovary of a plant that undergoes meiosis to product haploid megaspores

Question 52

Megaspore

Answer 52

One of the four products of meiosis in plants