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

The sequence of three bases which codes for a specified amino acid

Question 6

crossing over

Answer 6

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

Question 7

daughter ccell

Answer 7

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

Question 8

deletion

Answer 8

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

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 union of two gametes

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

Question 16

genetic code

Answer 16

a set of rules defining how the four-letter code of DNA is translated into the 20-letter code of amino acids

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

the alleles of two (or more) different genes get sorted into gametes independently 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 that reduces the number of chromosomes in the parent cell by half and produces four gamete cells

Question 23

meiosis I

Answer 23

a type of cell division unique to germ cells

Question 24

meiosis II

Answer 24

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

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

Question 28

nondisjunction

Answer 28

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

Question 29

offspring

Answer 29

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

Question 30

parent cell

Answer 30

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 31

point mutation

Answer 31

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

Question 32

replication

Answer 32

the process by which the genome's DNA is copied in cells

Question 33

sexual reproduction

Answer 33

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

Question 34

somatic cell

Answer 34

the cells in the body other than sperm and egg cells

Question 35

substitution

Answer 35

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

Question 36

trisomy

Answer 36

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

Question 37

trait

Answer 37

a specific characteristic of an individual