Unit 3 List 2 DNA & HEREDITY

Question 1

Allele

Answer 1

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Question 2

Centromere

Answer 2

the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, 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 threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

Question 5

Codon

Answer 5

a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis

Question 6

Crossing over

Answer 6

a cellular process that happens during meiosis when chromosomes of the same type are lined up

Question 7

Daughter cells

Answer 7

the cells that are formed after cell division

Question 8

Deletion

Answer 8

the removal or obliteration of written or printed matter, especially by drawing a line through it.

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

a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

Question 11

Fertilization

Answer 11

the action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote.

Question 12

Frameshift

Answer 12

a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read.

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 to a gene’s DNA sequence to produce something different. It creates a permanent change to that gene’s DNA sequence.

Question 16

Genetic code

Answer 16

the instructions contained in a gene that tell a cell how to make a specific protein. Each gene’s code uses the four nucleotide bases

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

a cell that contains a single set of chromosomes

Question 19

Homologous chromosome

Answer 19

pairs of chromosomes in a diploid organism that have similar genes, although not necessarily identical

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 1

Answer 22

a type of cell division unique to germ cells

Question 23

Meiosis 2

Answer 23

the sister chromatids within the two daughter cells separate, forming four new haploid gametes

Question 24

Monosomy

Answer 24

the condition of having a diploid chromosome complement in which one (usually the X) chromosome lacks its homologous partner.

Question 25

Mutagen

Answer 25

an agent, such as radiation or a chemical substance, which causes genetic mutation.

Question 26

Mutation

Answer 26

the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

Question 27

Nondisjunction

Answer 27

the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.

Question 28

Offspring

Answer 28

a person's child or children.

Question 29

Parent cell

Answer 29

A cell that is the source of other cells,

Question 30

Point mutation

Answer 30

A genetic alteration caused by the substitution of a single nucleotide for another nucleotide

Question 31

Replication

Answer 31

the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules

Question 32

Sexual reproduction

Answer 32

the production of new organisms by the combination of genetic information of two individuals of different sexes.

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 35

Trisomy

Answer 35

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

Question 36

Trait

Answer 36

a specific characteristic of an individual

Question 37

Meiosis

Answer 37

a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells