unit 3 list 2

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

structure in a chromosome that holds together the two chromatids

Question 2

chromatid

Answer 2

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

Question 3

chromosome

Answer 3

A structure found inside the nucleus of a cell

Question 4

codon

Answer 4

DNA or RNA sequence of three nucleotides (a trinucleotide) that forms a unit of genomic

Question 5

crossing over

Answer 5

the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis)

Question 6

daughter cell

Answer 6

the cells that are formed after cell division

Question 7

deletion

Answer 7

A type of genetic change that involves the absence of a segment of DNA

Question 8

diploid

Answer 8

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

Question 9

DNA

Answer 9

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

Question 10

fertilization

Answer 10

the union of two gametes

Question 11

frameshift

Answer 11

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

Question 12

gamete

Answer 12

a reproductive cell of an animal or plant

Question 13

gene

Answer 13

The basic unit of heredity passed from parent to child

Question 14

gene mutation

Answer 14

a change to a gene’s DNA sequence to produce something different

Question 15

genetic code

Answer 15

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

Question 16

genetic variation

Answer 16

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

Question 17

haploid

Answer 17

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

Question 18

homologous chromosome

Answer 18

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

Question 19

independent assortment

Answer 19

how different genes independently separate from one another when reproductive cells develop

Question 20

insertion

Answer 20

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

Question 21

meiosis

Answer 21

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

Question 22

meiosis I

Answer 22

a type of cell division unique to germ cells

Question 23

meiosis II

Answer 23

a mitotic division of each of the haploid cells produced in meiosis I

Question 24

monosomy

Answer 24

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 25

mutagen

Answer 25

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

Question 26

mutation

Answer 26

is a change in the DNA sequence of an organism

Question 27

nondisjunction

Answer 27

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

Question 28

offspring

Answer 28

the young creation of living organisms, produced either by sexual or asexual reproduction

Question 29

parent cell

Answer 29

something thought of as an overhanging shelter

Question 30

point mutation

Answer 30

occurs in a genome when a single base pair is added, deleted or changed

Question 31

replication

Answer 31

double-stranded DNA molecule is copied into two, identical DNA

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