genetics definitions

Question 1

Inheritance

Answer 1

a characteristic of an organism that depends on its genes

Question 2

Maternal & Paternal Chromosomes

Answer 2

Maternal chromosome: chromosome received from the female

Paternal chromosome: chromosomes received from the male

Question 3

Allele

Answer 3

one version of a gene, found at specific location along a chromosome

Question 4

Dominant trait

Answer 4

A trait that will appear in the offspring if a parent contributes to it.

Question 5

Recessive trait

Answer 5

Traits that can be carried in a person’s genes that is not visible

Question 6

Homozygous

Dominant

Answer 6

Both alleles are the same. Offspring that inherit two dominant genes are known as Homozygous Dominant. E.g. RR

Question 7

Homozygous

Recessive

Answer 7

Both alleles are the same. Offspring that inherit two recessive genes are known as Homozygous recessive. E.g. rr

Question 8

Heterozygous

Answer 8

having 2 different alleles of a specific gene E.g. Rr

Question 9

Carrier

Answer 9

An individual with a recessive allele, whose effect is masked by a dominant allele

Question 10

Genotype

Answer 10

the full set of genes of an organism

Question 11

Phenotype

Answer 11

all the observable characteristics of an organism

Question 12

Karyotype

Answer 12

A picture of all the chromosomes from an individual’s cells used to check for chromosome abnormalities.

Question 13

Homologous chromosomes

Answer 13

Chromosomes with genes for particular characteristics at the same location

Question 14

Autosomes

Answer 14

Any chromosome that is not a sex chromosome

Question 15

Sex chromosomes

Answer 15

The chromosomes that determines the sex of an individual; in humans they are the X and Y chromosomes. There are 2 in each cell ( XX/ XY).

Question 16

Punnett Square

Answer 16

A way of showing all the possible types of offspring that could result from a cross.

Question 17

Pedigree

Answer 17

The record of descent of an animal, showing it to be pure-bred

Question 18

Sex-linked inheritance

Answer 18

The genes found on the X chromosomes not the Y. Making one chromosome present that is responsible for the determination of a sex.

Question 19

Incomplete dominance

Answer 19

a situation where 2 alleles are both partially expressed, producing an intermediate phenotype
e.g. pink snap dragon

Question 20

co dominance

Answer 20

a situation where 2 alleles are equally dominant

e.g. blood groups

Question 21

Genetic mutation

Answer 21

Genetic mistakes in the code of genes

Question 22

Human genome

Answer 22

All of the genes found in humans.

Question 23

Amniocentesis test

Answer 23

Taking fluid from the amniotic sack. This tests for sex and genetic disorders.

Question 24

continuous

Answer 24

variation represented by a continuous range of values and which can be measured

Question 25

discontinuous

Answer 25

variation represented by discrete categories

Question 26

dominant

Answer 26

an allele that is always expressed, even if the cell only contains one copy

Question 27

gene

Answer 27

a unit of inheritance

Question 28

monohybrid cross

Answer 28

a cross in which one pair of characteristics is studied