reproduction

Question 1

allele

Answer 1

an alternative version of a gene

Question 2

chromosome

Answer 2

a long molecule of DNA found in the nucleus of cells

Question 3

dominant

Answer 3

allele that only needs one copy to be expressed

Question 4

fertilisation

Answer 4

the fusion of male and female gametes during sexual reproduction

Question 5

gamete

Answer 5

a sex cell, e.g. and egg cell or a sperm cell

Question 6

gene

Answer 6

part of a chromosome that codes for a protein - some characteristics are controlled by a single gene but most are controlled by genes mixing interacting

Question 7

genotype

Answer 7

combination of alleles an individual has

Question 8

heterozygous

Answer 8

when an individual carries two different alleles for a trait

Question 9

homozygous

Answer 9

when an individual carries two copies of the same allele for a trait

Question 10

meiosis

Answer 10

a type of cell division where a cell divides twice to to produce four genetically different gametes - occurs in the reproductive organs

Question 11

mitosis

Answer 11

a type of cell division where a cell reproduces itself by splitting to form two identical offspring

Question 12

phenotype

Answer 12

physical expression of the genotype - the characteristic shown

Question 13

recessive

Answer 13

allele that needs two copies present to be expressed

Question 14

cystic fibrosis

Answer 14

an inherited disorder of the cell membranes caused by a recessive allele

Question 15

DNA

Answer 15

deoxyribonucleic acid - the molecule in cells that stores genetic information

Question 16

double helix

Answer 16

the structure of DNA

Question 17

expression

Answer 17

the appearance in a phenotype of a characteristic or effect attributed to a particular gene

Question 18

gene

Answer 18

a short section of DNA, found on a chromosome, which contains the instructions needed to make a protein

Question 19

genetic cross

Answer 19

when the offspring that might result from two known parents is considered

Question 20

genome

Answer 20

all the genetic material in an organism

Question 21

nucleotide

Answer 21

a repeating unit in DNA and RNA that consists of a sugar, a phosphate group and a base

Question 22

polydactyly

Answer 22

an inherited disorder, caused by a dominant allele, where a person has extra fingers or toes

Question 23

polymer

Answer 23

a long chain molecule that is formed by joining lots of smaller molecules (monomers) together

Question 24

punnett square

Answer 24

a type of genetic diagram