Genetics Vocabulary

Front 1

Nucleus

Back 1

Cell part that contains chromosomes

Front 2

Deoxyribo-Nucleic Acid

Back 2

Substance carrying organisms genetic information

Front 3

Chromosome

Back 3

Threadlike structure of DNA and protein found in the nucleus of cells - Carries genetic information in the form of genes

Front 4

Homologous Chromosomes

Back 4

Having the same structural features (length) and pattern of genes.

Front 5

Karotype

Back 5

Photograph of an individual's chromosomes cut out and arranged according to their size

Front 6

Gene

Back 6

Short length of DNA that carries the genetic code for a particular trait/characteristic or cell activity

Front 7

Allele

Back 7

Different forms of the same gene - they can be dominant or recessive

Front 8

Base

Back 8

Parts of DNA involved in pairing - cytosine, guanine, adenine and thymine.

Front 9

Nucleotide

Back 9

Forms the basic structural unit of DNA, composed of a sugar molecule, a phosphate group, and a base pairing.

Front 10

DNA

Back 10

Carries instructions to the next generation and determines the phenotype

Front 11

Trait

Back 11

A genetically determined characteristic.

Front 12

Variation

Back 12

Differences between organisms within a population - Can be continuous (e.g height) or discontinuous (e.g hitchhikers thumb)

Front 13

Mitosis

Back 13

Cell division body cells for growth and repair - produces two new cells - produces two new cells genetically identical to each other and the parent cell.

Front 14

Meiosis

Back 14

Cell division in testes and ovaries producing 4 new cells (gametes) - Genetically different to each other, and to the parent cell.

Front 15

Gamete

Back 15

Reproductive cells that contain half the number of chromosomes compared to the parent cell.

Front 16

Zygote

Back 16

A fertilised ovum (egg) that contains the full set of chromosomes

Front 17

A-Sexual Reproduction

Back 17

Reproduction involving only one parent (usually female) - offspring genetically identical to the parent and to eachother

Front 18

Sexual Reproduction

Back 18

Reproduction involving two parents - offspring different to the parent and to each other

Front 19

Clone

Back 19

Organism produced asexually from one parent - offspring genetically identical to both it's parent and sibling.

Front 20

Trait

Back 20

A genetically determined characteristic

Front 21

Mutation

Back 21

A permanent change in the base sequence of DNA

Front 22

Allele

Back 22

Different forms of the same gene

Front 23

Genotype

Back 23

The particular alleles of an organism

Front 24

Phenotype

Back 24

The observable characteristics of an individual resulting from it's genotype

Front 25

Pure Breeding

Back 25

Individuals that are homozygous - will always produce the same offspring when crossed together.

Front 26

Homozygous

Back 26

An individual with two alleles that are the same for a particular trait

Front 27

Heterozygous

Back 27

An individual with two alleles that are different for a particular trait

Front 28

Test Cross

Back 28

Cross between an unknown genotype organism and a homozygous recessive to work out the genotype from the offspring.

Front 29

Dominant

Back 29

Allele which is always expressed even if only one is present - written with an uppercase letter

Front 30

Recessive

Back 30

Allele which is only expressed when two of them are present - written with a lower case letter

Front 31

Pedigree Chart

Back 31

Diagram / Family Tree that shows the phenotypes of related individuals

Front 32

Haploid

Back 32

Having a single set of chromosomes (n)

Front 33

Diploid

Back 33

Having a full set of chromosomes (2n); having a pair of each type of chromosome

Front 34

Carrier

Back 34

Individual that carries a gene for a particular recessive trait, does not express the trait, but can pass that trait on.

Front 35

Amino Acids

Back 35

Basic building blocks of proteins

Front 36

Double Helix

Back 36

Two strands of nucleotides that are wound around each other - Structure of DNA

Front 37

Fertilisation

Back 37

The joining of male and female gametes

Front 38

Offspring

Back 38

Product of reproduction - a new organism produced by one or more parents

Front 39

Proteins

Back 39

Made up of amino acids. There are many types and all have important roles in living systems

Front 40

Punnett Square

Back 40

A chart that shows all the possible combinations of alleles that can result from a genetic cross

Front 41

Semi-Conservative Replication

Back 41

In each new DNA Double Helix, one stand is from the original molecule and one strand is new.

Front 42

Sex Chromosomes

Back 42

Chromosomes X and Y that determine the sex of an individual

Front 43

Crossing Over

Back 43

Exchange of genetic material between homologous chromosomes

Front 44

Mutation

Back 44

Process responsible for forming new alleles

Front 45

Variation

Back 45

Important to population and species survival in a changing environment

Front 46

Changing Environment

Back 46

Pest infestation, disease, drought, or flood could be examples of a changing environment

Front 47

Independent Assortment

Back 47

Each homologous pair of chromosomes lines up at the equator - maternal or paternal - independently of other homologous pairs