Mitosis and Meiosis Test Expectations+

Question 1

Define: Haploid

Answer 1

The term used to describe a single set of chromosomes that equals half the diploid count. In humans, haploid count equals 23.

Question 2

Define: Diploid

Answer 2

The term used to describe a complete set of chromosomes, consisting of one from each parent. Humans have a diploid count of 46.

Question 3

Define: Chromosome

Answer 3

The means of storage for DNA in a cell or organism. Every species has a distinct number,

Question 4

Define: Sister chromatid

Answer 4

A pair of identical chromosomes, derived from the division of a single chromosome, that align at a common centromere

Question 5

Define: Centromere

Answer 5

(Greek, CENTR-, “center”) The central point at which a pair of sister chromatid attach to one another

Question 6

Define: Tetrad

Answer 6

(Greek, TETRA-, “four”) A group of four chromatids formed by pairs of homologous chromosomes

Question 7

Define: Tetrad

Answer 7

(Greek, TETRA-, “four”) A group of four chromatids formed by pairs of homologous chromosomes

Question 8

Define: Synapsis

Answer 8

A process during which homologous chromosomes come together as pairs. It is during this process that four-chromatid complexes called tetrads are made.

Question 9

Define: Homologous chromosomes

Answer 9

Chromosomes that have the same size, shape, and genes, but may contain different versions of these genes

Question 10

Define: Crossing over

Answer 10

The process in meiosis (specifically prophase I) during which two non-sister chromatids exchange elements of DNA, beginning when the two genetically different chromatids come into contact at the chiasma

Question 11

Define: Mutation

Answer 11

An irreversible change in the nucleotide sequence of an organism’s genome

Question 12

Define: Point mutation

Answer 12

A type of mutation that causes only a single nucleotide base to change, in addition to insertion or deletion of DNA or RNA

Question 13

Define: Chromosome mutation

Answer 13

A change that affects protein production and can lead to alterations to a chromosome’s physical structure that are more or less harmful to its function

Question 14

State the sequence of mitosis (4 phases)

Answer 14

Prophase
Metaphase
Anaphase
Telophase

Question 15

State the sequence of mitosis (4 phases)

Answer 15

Prophase
Metaphase
Anaphase
Telophase

Question 16

State the sequence of meiosis I (5 phases)

Answer 16

Prophase I
Crossing over
Metaphase I
Anaphase I
Telophase I

Question 17

State the sequence of meiosis II (5 phases)

Answer 17

Prophase II
Metaphase II
Anaphase II
Telophase II
Cytokinesis

Question 18

Describe the function of cell division in prokaryotes

Answer 18

In prokaryotes, the primary function of cell division is to make asexual reproduction possible.

Question 19

Describe the function of cell division in eukaryotes

Answer 19

In eukaryotes, cell division is the primordial means for growth and reparation of cells. It also allows an organism to contribute unique DNA to its offspring.

Question 20

Describe the function of cell division in eukaryotes

Answer 20

In eukaryotes, cell division is the primordial means for growth and reparation of cells. It also allows an organism to contribute unique DNA to its offspring.

Question 21

State the result of mitosis

Answer 21

Mitosis results in 2 new daughter cells that are identical to their parents and each other.

Question 22

State the result of meiosis

Answer 22

As opposed to mitosis, meiosis results in four new haploid cells. The process is specific to sexual reproduction, and also results in the production of gametes.

Question 23

How does meiosis increase genetic variability?

Answer 23

Offspring that result from sexual reproduction are highly varied, as they are genetically different from their parents and from one another. Crossing over during meiosis also adds variability, because it involves combining the genes from two genetically diverse non-sister chromatids.

Question 24

How does meiosis increase genetic variability?

Answer 24

Offspring that result from sexual reproduction are highly varied, as they are genetically different from their parents and from one another. Crossing over during meiosis also adds variability, because it involves combining the genes from two genetically diverse non-sister chromatids.

Question 25

Describe sister chromatids

Answer 25

Sister chromatids are identical to one another. They are conjoined at a common centromere. They equal one-half of a duplicated chromosome.

Question 26

List the five event common to prophase in both mitosis and meiosis

Answer 26

``` The nucleus disappears The nucleolus dissolves The chromosomes condense Spindle fibers form to traverse the cell Centrioles begin to move to opposite poles of the cell ```

Question 27

Outline the steps of meiosis (I and II)

Answer 27

Meiosis I Prophase I: synapsis, crossing over, tetrads become visible Metaphase: tetrads (now visible) align at the center of the cell Anaphase I: tetrads begin to separate and chromosome pairs shift toward opposing ends of the cell, while the sister chromatids remain intact Telophase: each pole now contains a haploid set of chromosomes

Question 28

Outline the steps of meiosis (I and II)

Answer 28

Meiosis I Prophase I: synapsis, crossing over, tetrads become visible Metaphase I: tetrads (now visible) align at the center of the cell Anaphase I: tetrads begin to separate and chromosome pairs shift toward opposing ends of the cell, while the sister chromatids remain intact Telophase: each pole now contains a haploid set of chromosomes Meiosis II Prophase II: (identical to prophase I: preparatory) Metaphase II: independent sister chromatids align at center Anaphase II: chromatids separate Telophase II: each side of the 2 resulting cells contains the haploid number of chromosomes

Question 29

Outline the steps of meiosis (I and II)

Answer 29

Meiosis I Prophase I: synapsis, crossing over, tetrads become visible Metaphase I: tetrads (now visible) align at the center of the cell Anaphase I: tetrads begin to separate and chromosome pairs shift toward opposing ends of the cell, while the sister chromatids remain intact Telophase: each pole now contains a haploid set of chromosomes Meiosis II Prophase II: (identical to prophase I: preparatory) Metaphase II: independent sister chromatids align at center Anaphase II: chromatids separate Telophase II: each side of the 2 resulting cells contains the haploid number of chromosomes Cytokinesis: results in 4 haploid daughters that are each genetically unique

Question 30

Explain crossing over

Answer 30

Crossing over occurs when 2 non-sister chromatids exchange genetic material during prophase I. It increases genetic variability in sexually reproducing organisms and is therefore very important to sexual reproduction.

Question 31

Compare cytokinesis in plants and animals. There is ONE primary difference between the two processes.

Answer 31

Cytokinesis in both plants and animals begins toward the conclusion of telophase. However, in plants, the rigid cell wall prevents the cell from "pinching in" like in animal cells.

Question 32

Compare gametes and somatic cells

Answer 32

Gametes is the collective term used for sex cells in animals, or the sperm and the egg. Somatic cells, on the other hand, include every other body cell.

Question 33

Compare haploid cells and diploid cells

Answer 33

A cell is said to be haploid when it contains only a single set of chromosomes. Conversely, a cell is diploid if it contains two complete sets of chromosomes.

Question 34

What is the formula for calculating the number of possible combination of chromosomes in a sexually reproducing organism? (Hint: the equation consists of a number and a coefficient.)

Answer 34

The formula for calculating the number of possible combination of chromosomes in a sexually reproducing organism is 2n, where coefficient n is the haploid number,

Question 35

What is the formula for calculating the number of possible combination of chromosomes in a sexually reproducing organism? (Hint: the equation consists of a number and a coefficient.)

Answer 35

The formula for calculating the number of possible combination of chromosomes in a sexually reproducing organism is 2n, where coefficient n is the haploid number.

Question 36

Name the three possible outcomes of mutation

Answer 36

Deletion Insertion Substitution

Question 37

Compare point mutation and chromosomal mutation

Answer 37

A point mutation affects only a single portion of DNA or RNA or a base, while a chromosomal mutation goes on to alter long segments of a chromosome's structure.

Question 38

Describe spontaneous mutation

Answer 38

Spontaneous mutations arise from complications in replication. During spontaneous mutations, different genes mutate at various rates.

Question 39

Describe spontaneous mutation

Answer 39

Spontaneous mutations arise from complications in replication. During spontaneous mutations, different genes mutate at various rates.

Question 40

Describe induced mutations

Answer 40

Induced mutations are often caused (or induced) by environmental factors that stimulate change in DNA.

Question 41

Compare substitution and insertion, two different outcomes of mutation

Answer 41

Substitution is the replacement of one nucleotide by another one (i.e. a purine and a pyrimidine) On the contrary, insertion is the addition of one or more bases to a region of the DNA.

Question 42

Describe inversion (chromosomal mutation)

Answer 42

Inversion occurs when genes appear reversed because some pieces of a chromosome have been flipped.

Question 43

Describe translocation (chromosomal mutation)

Answer 43

Translocation occurs when pieces from one chromosome are moved to another. (Hence trans - location)

Question 44

Describe duplication (chromosomal mutation)

Answer 44

Duplication occurs when chromosomes repeat themselves, creating duplicatees

Question 45

Describe duplication (chromosomal mutation)

Answer 45

Duplication occurs when chromosomes repeat themselves, creating duplicate segments.

Question 46

Describe insertion (chromosomal mutation)

Answer 46

When pieces are added to a chromosome

Question 47

Describe deletion (chromosomal mutation)

Answer 47

When pieces are lost

Question 48

Describe nondisjunction

Answer 48

Nondisjunction is an overflow of chromosomes in a gamete caused by homologous chromosomes' failure to separate.

Question 49

What is the name of the site where two sister chromatids come together during crossing over?

Answer 49

The chiasma (pl. chiasmata)

Question 50

State the name of the process that restores the diploid number after meiosis

Answer 50

Fertilization