biology notes

Question 1

mitosis

Answer 1

a type of cell division that produces cells for growth and repair

Question 2

sex chromosome

Answer 2

a chromosome that helps determine an organisms sex

Question 3

adenine

Answer 3

the base that combines with thymine to form a base pair

Question 4

crossing over

Answer 4

the swapping of genes between chromosomes in a homologous pair

Question 5

generation

Answer 5

members of a family that are born and live at about the same time

Question 6

metaphase

Answer 6

a stage of cell division in which the chromosomes line up

Question 7

recessive trait

Answer 7

a feature that only appears when two alleles are present

Question 8

cell cycle

Answer 8

the repeated process of cell growth and division

Question 9

double helix

Answer 9

a structure consisting of two chains twisted around each other

Question 10

inheritance

Answer 10

the passing down of traits via genes from one generation to the next

Question 11

prophase

Answer 11

a stage of cell division in which the chromosomes condense

Question 12

cell division

Answer 12

the splitting of a cell to from new cells

Question 13

fertilization

Answer 13

the joining of an egg and a sperm to form a new organism

Question 14

interphase

Answer 14

the stage of the cell cycle in which a cell grows and copies its DNA

Question 15

protein

Answer 15

a large molecule made up of amino acids

Question 16

chromosome

Answer 16

a DNA molecule that condenses during cell division

Question 17

gene

Answer 17

a unit of genetic information

Question 18

meiosis

Answer 18

a type of cell division that produces sex cells for reproduction

Question 19

recessive allele

Answer 19

a version of a gene that is only expressed when two copies are present

Question 20

genotype

Answer 20

a pair of alleles that influence the appearance of a particular trait

Question 21

cytosine

Answer 21

the base that combines with guanine to form a base pair

Question 22

allele

Answer 22

a version of a gene

Question 23

simple inheritance

Answer 23

when the appearance of a trait controlled by a single gene

Question 24

mutation

Answer 24

a permanent change in the sequence of bases that make up a gene

Question 25

guanine

Answer 25

the base that combines with cytosine to form a base pair

Question 26

daughter cell

Answer 26

any new cell formed by cell division

Question 27

amino acid

Answer 27

a small molecule that joins with others to form proteins

Question 28

telophase

Answer 28

a stage of cell division in which two nuclei form

Question 29

parent cell

Answer 29

any cell that divides to form new cells

Question 30

heterozygous

Answer 30

a genotype in which the two alleles are different

Question 31

DNA

Answer 31

a molecule that contains genetic information

Question 32

anaphase

Answer 32

a stage of cell division in which the chromosomes separate

Question 33

thymine

Answer 33

the base that combines with adenine to form a base pair

Question 34

pedigree

Answer 34

a family tree that shows how a trait is passed down through generations

Question 35

homologous pair

Answer 35

two chromosomes that contain versions of the same genes

Question 36

dominant allele

Answer 36

a version of a gene that is expressed even when only one copy is present

Question 37

base

Answer 37

part of a DNA molecule that comes in four type: A,C,G,T

Question 38

trait

Answer 38

a feature of an organism

Question 39

phenotype

Answer 39

the collection of traits observable in an organism

Question 40

homozygous

Answer 40

a genotype in which the two alleles are the same

Question 41

dominant trait

Answer 41

a feature that appears when at least one allele is present

Question 42

base pair

Answer 42

two bases joined together