Unit 3 List 2 DNA & Heredity

Question 1

Allele

Answer 1

One of two or more versions of a genetic sequence at a particular region on a chromosome

Question 2

Centromere

Answer 2

The region of the chromosome to which the spindle fiber is attached during cell division

Question 3

Chromatid

Answer 3

one of the two identical halves of a chromosome that has been replicated in preparation for cell division

Question 4

Chromosome

Answer 4

A structure found inside the nucleus of a cell

Question 5

Codon (chart)

Answer 5

shows all of the possible three letter combinations of mRNA nucleotides, and for which amino acid each combination codes for

Question 6

Crossing over

Answer 6

the exchange of genes between two chromosomes, resulting in non-identical chromatids that comprise the genetic material of gametes

Question 7

Daughter cell

Answer 7

Either of the two cells formed when a cell undergoes cell division by mitosis

Question 8

Depletion

Answer 8

The act or process of emptying, removal of a fluid, as the blood.

Question 9

Diploid

Answer 9

the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair.

Question 10

DNA

Answer 10

the molecule that carries genetic information for the development and functioning of an organism

Question 11

Fertilization

Answer 11

The process of combining the male gamete, or sperm, with the female gamete, or ovum

Question 12

Frameshift

Answer 12

the insertion or deletion of nucleotide bases in numbers that are not multiples of three

Question 13

Gamete

Answer 13

a reproductive cell of an animal or plant

Question 14

Gene

Answer 14

The basic unit of heredity passed from parent to child

Question 15

Gene mutation

Answer 15

a change in one or more genes

Question 16

Genetic code

Answer 16

the instructions contained in a gene that tell a cell how to make a specific protein.

Question 17

Genetic variation

Answer 17

the presence of differences in sequences of genes between individual organisms of a species

Question 18

Haploid

Answer 18

the presence of a single set of chromosomes in an organism’s cells

Question 19

Homologous chromosome

Answer 19

pairs of chromosomes originating from each parent. A cell would have two copies of chromosome 1 for example; one from the mother and one from the father.

Question 20

Independent assortment

Answer 20

a genetic principle that states that the alleles of two genes will segregate into daughter cells independent of one another

Question 21

Insertion

Answer 21

a type of mutation that involves the addition of one or more nucleotides into a segment of DNA

Question 22

Meiosis

Answer 22

a type of cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes

Question 23

Meiosis I

Answer 23

The first of the two consecutive divisions of the nucleus of eukaryotic cell during meiosis, and composed of the following stages: prophase I, metaphase I, anaphase I, and telophase I.

Question 24

Meiosis II

Answer 24

the second division in meiosis in which chromatids of each chromosome are segregated equally into daughter cells. No DNA replication occurs during the interphase which precedes meiosis II.

Question 25

Monosomy

Answer 25

the condition in which only one chromosome from a pair is present in cells rather than the two copies usually found in diploid cells

Question 26

Mutagen

Answer 26

a chemical or physical agent capable of inducing changes in DNA called mutations

Question 27

Mutation

Answer 27

Any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment.

Question 28

Nondisjunction

Answer 28

the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes

Question 28

Offspring

Answer 28

the product of the reproductive processes of a person, animal, or plant

Question 29

Parent cell

Answer 29

A cell that is the source of other cells, as a cell that divides to produce two or more daughter cells, or a stem cell that is a progenitor of other cells or is the first in a line of developing cells

Question 30

Point mutation

Answer 30

change within a gene in which one base pair in the DNA sequence is altered

Question 31

Replication

Answer 31

a biological process of duplicating or producing an exact copy, such as a polynucleotide strand (DNA)

Question 32

Sexual reproduction

Answer 32

occurs when the sperm from the male parent fertilizes an egg from the female parent, producing an offspring that is genetically different from both parents

Question 33

Somatic cell

Answer 33

the cells in the body other than sperm and egg cells

Question 34

Substitution

Answer 34

a type of mutation in which one nucleotide is replaced by a different nucleotide

Question 34

Trisomy

Answer 34

The presence of an extra chromosome in some or all of the body’s cells

Question 34

Trait

Answer 34

a specific characteristic of an individual. Traits can be determined by genes, environmental factors or by a combination of both. Traits can be qualitative (such as eye color) or quantitative (such as height or blood pressure).