Module 2

Question 1

Unicellular organism with a relatively simple cell structure. Prokaryotes include bacteria (eubacteria) and archaea.

Answer 1

Prokaryote

Question 2

One of the three primary divisions of life, consisting of prokaryotic unicellular organism.

Answer 2

Bacteria

Question 3

one of the three primary divisions of life, consisting of unicellular organisms with prokaryotic cell structure.

Answer 3

Archaea

Question 4

One of the three primary divisions of life; an organism that has a compartmentalized cell structure, including a nuclear envelope and membrane-bounded organelles. Eukaryotes may be unicellular or multicellular.

Answer 4

Eukaryote

Question 5

Compartment in eukaryotic cells that is enclosed by the nuclear membrane and contains the genetic material.

Answer 5

Nucleus

Question 6

Low-molecular-weight protein found in eukaryotes that associates closely with DNA to form chromosomes.

Answer 6

Histone

Question 7

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

Answer 7

Chromatin

Question 8

A pair of chromosomes that are alike in structure and size and that carry genetic information for the same set of hereditary characteristics. One chromosome of a homologous pair is inherited from the male parent, and the other is inherited from the female parent.

Answer 8

Homologous pair

Question 9

Possessing two sets of chromosomes

Answer 9

diploid

Question 10

possessing a single set of chromosomes

Answer 10

haploid

Question 11

Formula?

Answer 11

2n and n - The total number of chromosomes in diploid cells is described as 2n, which is twice the number of chromosomes in a haploid cell (n).

Question 12

Constricted region on a chromosome that stains less strongly than the rest of the chromosome; serves as the attachment point for spindle microtubules.

Answer 12

Centromere

Question 13

Microtubule that moves chromosomes in mitosis and meiosis.

Answer 13

Spindle microtubules

Question 14

Chromosome in which the centromere is displaced toward one end, producing a short arm and a long arm.

Answer 14

submetacentric

Question 15

Chromosome in which the two chromosome arms are approximately the same length.

Answer 15

Metacentric

Question 16

Chromosome in which the centromere is at or very near one end.

Answer 16

Telocentric

Question 17

Chromosome in which the centromere is near one end, producing a long arm at one end and a knob, or satellite, at the other end.

Answer 17

Acrocentric

Question 18

Stable end of a eukaryotic chromosome

Answer 18

Telomere

Question 19

Set of proteins that assemble on the centromere, providing the point of attachment for spindle microtubules.

Answer 19

Kinetochore

Question 20

site where DNA replication is initiated

Answer 20

Origin of replication

Question 21

site where DNA replication is initiated

Answer 21

origin of replication

Question 22

Two copies of a chromosome that are held together at the centromere. Each sister chromatid consists of a single molecule of DNA.

Answer 22

sister chromatid

Question 23

(G1, S, G2, M phase) - Stages through which a cell passes from one cell division to the next. G1, S, G2 together are known as interphase. In G1, the cell grows and develops. This is followed by S (synthesis) phase where DNA replicates. G2 follows DNA replication, and during this phase, the cell prepares for division. Next is the mitotic (M) phase which is the major phase of the cell cycle that encompasses active cell division; includes mitosis (nuclear division) and cytokinesis (cytoplasmic division).

Answer 23

Cell cycle

Question 24

Major phase of the cell cycle between cell divisions. In interphase, the cell grows, develops, and functions.

Answer 24

interphase

Question 25

process by which the nucleus of a eukaryotic cell divides

Answer 25

mitosis

Question 26

process by which the cytoplasm of a cell divides

Answer 26

cytokinesis

Question 27

Stage of mitosis in which the chromosomes contract and become visible, the cytoskeleton breaks down, and the mitotic spindle begins to form.

Answer 27

prophase

Question 28

Stage of mitosis in which the nuclear membrane breaks down and the spindle microtubules attach to the chromosomes.

Answer 28

prometaphase

Question 29

stage of mitosis in which chromosomes align in the center of the cell

Answer 29

metaphase

Question 30

stage of mitosis in which sister chromatids separate and move towards opposite spindle poles

Answer 30

anaphase

Question 31

stage of mitosis in which the chromosomes arrive at the spindle poles, the membrane re-forms, and the chromosomes relax and lengthen

Answer 31

telophase

Question 32

(Meiosis I and Meiosis II) - Process by which the chromosomes of a eukaryotic cell divide to give rise to haploid reproductive cells. Consists of two divisions: meiosis I and meiosis II. Meiosis I is the first phase of meiosis and is where the chromosome number is reduced by half. Meiosis II is the second phase of meiosis, and its Events are similar to those in mitosis.

Answer 32

Meiosis

Question 33

fusion of gametes (sex cells) to form a zygote

Answer 33

fertilization

Question 34

I and II – In prophase I of meiosis I, the chromosomes condense and pair, crossing over takes place, the nuclear membrane breaks down, and the mitotic spindle forms. In prophase II of meiosis II, the events of interkinesis are reversed; chromosomes recondense, the spindle re-forms, and the nuclear membrane breaks down. Some cells skip this stage.

Answer 34

prophase

Question 35

close pairing of homologous chromosomes

Answer 35

synapsis

Question 36

A homologous pair of synapsed chromosomes consisting of four chromatids; also called a tetrad.

Answer 36

bivalent

Question 37

A homologous pair of synapsed chromosomes consisting of four chromatids; also called bivalent.

Answer 37

tetrad

Question 38

Exchange of genetic material between homologous but non-sister chromatids.

Answer 38

crossing over

Question 39

I and II – In metaphase I of meiosis I, homologous pairs of chromosomes align in the center of the cell along the metaphase plate. In metphase II of meiosis II, individual chromosomes align in the center of the cell.

Answer 39

metaphase

Question 40

I and II – In anaphase I of meiosis I, the homologous chromosomes separate and move toward the spindle poles. In anaphase II of meiosis II, sister chromatids separate and the chromatids are pulled to opposite poles.

Answer 40

anaphase

Question 41

I and II – In telophase I of meiosis I, chromosomes arrive at the spindle poles. In telophase II of meiosis II, chromosomes arrive at the spindle poles.

Answer 41

telophase

Question 42

period between meiosis I and meiosis II

Answer 42

interkinesis

Question 43

process that produces new combinations of alleles

Answer 43

recombination

Question 44

A protein that holds the two sister chromatids of a chromosome together. The breakdown of cohesin at the centromeres enables the chromatids to separate in anaphase of mitosis and anaphase II of meiosis.

Answer 44

Cohesion

Question 45

The process where the chromosomes move randomly to separate poles during meiosis.

Answer 45

independent assortment

Question 46

What do eubacteria and archaea have in common that distinguish them from eukaryotes?

Answer 46

eubacteria and archaea are prokaryotes they differ from eukaryotes in possessing no nucleus a genome that usually consists of a single circular chromosome, and a small amount of DNA

Question 47

Diploid cells have: a. two chromosomes b. two sets of chromosomes c. one set of chromosomes d. two pairs of homologous chromosomes

Answer 47

b. two sets of chromosomes

Question 48

What would be the result if a chromosome not have a kinetochore?

Answer 48

it is where microtubules attach to the chromosome. if it were missing the microtubules would not attach to the chromsome

Question 49

Phases of the Cell Cycle

Answer 49

G1 - growth G0 - may enter a non-dividing phase S - DNA duplicates G2 - cell prepares for mitosis M phase - mitosis and cytokinesis

Question 50

Which is the correct order of the stages cycle? i) anaphase ii) prophase iii) G1 iv) S v) metaphase

Answer 50

G1, S, prophase, metaphase anaphase

Question 51

which of the following events takes place in metaphase I? a) crossing over occurs b) the chromosomes condense c. homologous pairs of chromosomes line up on the metaphase plate. d. individual chromosomes line up on the metaphase plate

Answer 51

c. homologous pairs of chromosomes line up on the metaphase plate

Question 52

How many chromosomes and homologous chromosomes do humans have?

Answer 52

46 chromosomes, and 23 sets of homologous chromosomes

Question 53

constricted region on a chromosome that serves as the attachment point for spindle microtubules

Answer 53

centromere

Question 54

stable ends of a eukaryotic chromosome that prevent the chromosome from progressive degradation and helps to maintain its integrity.

Answer 54

telomeres

Question 55

the site where DNA replication is initiated

Answer 55

origin of replication

Question 56

the constricted area of a chromosome

Answer 56

centromere

Question 57

each arrow is pointing to the ends of the chromosome which are called telomeres

Answer 57

telomeres

Question 58

because we see an "X" we have a pair of chromatids which are called sister chromatids; i.e., a single chromatid has been copied/duplicated during S phase

Answer 58

sister chromatids

Question 59

What is independent assortment

Answer 59

refers to the random separation of homologous chromosomes during meiosis I.

Question 60

what is crossing over

Answer 60

refers to the exchange of genetic data between homologous chromosomes, which occurs during prophase I