Different forms of the same gene - they can be dominant or recessive
allele
trait
a fertilized ovum/egg that contains the full set of chromosomes
zygote
gamete
allele which is always expressed even if only one is present- written with an upper-case letter e.g. "A"
dominant
recessive
threadlike structure of DNA and protein found in the nucleus of cells- carries genetic information in the form of genes
nucleotide
chromosome
cell
cell part that contains chromosomes
nucleus
gene
meiosis
cell division in testies and ovaries producing four new cells (gametes) - genetically different to each other, and to the parent cell
cell division body cells for growth and repair - produces 2 new cells genetically identical to each other and to the parent cell
exchange of genetic information between homologous chromosomes
crossing over
independent assortment
cross between unknown genotype organism and a homozygous recessive to work out the genotype of the offspring
punnet square
test cross
short length of DNA that carries the genetic code for a particular trait/characteristic or cell activity
DNA
having the same structural features (length) and pattern of genes
homozygous chromosomes
variation
homologous chromosomes
mutation
a genetically determined characteristic
cell division body cells for growth and repair - produces 2 new cells genetically identical to each other and the parent cell
mitosis
process responsible for forming new alleles
chromosomes X and Y that determine the sex of an individual
sex chromosomes
individuals that are homozygous - will always produce the same offspring when crossed together
pure breeding
sexual reproduction
pest infestation, disease, drought or flood could be examples of a... Changing environment
having a full set of chromosomes (2n); having a pair of each type of chromosome
diploid
haploid
organisim produced asexually from one parent - offspring identical to both its parent and siblings
clone
homozygous
substance carrying organism's genetic information
deoxyribonucleic acid
difference between organisms within a population - can be continuous or discontinuous
the observable characteristics of an individual resulting from its genotype
phenotype
genotype
forms the basic stuctural unit of DNA, composed of a sugar molecule, a phosphate group and a base
amino acids
basic building blocks of proteins
the particular alleles of an organisim
an individual with two alleles that are different for a particular trait
heterozygous
an individual with two alleles that are the same for a particular trait
individual that carries a gene for a particular trait, does not express the trait, but can pass that trait on
carrier
sexual reproduction involves two parents - offspring are different to the parent and to each other
the joining of the male and female gamete is called fertilization
allele which is only expressed when two of them are present - written in a lower-case letter E.g. 'a'
allele which is always expressed even if only one is present - written with an upper-case letter E.g. 'A'
name for the offspring of the cross BB x bb and their offspring and their offspring...
F1 generation
F2 generation
F3generation
What are the parts of DNA involved in pairing
cytosine
guanine
adenine
thymine
reproductive cells that contain half the number of chromosomes compared to the parent cell
body cells that contain the same number of chromosomes as the parent cell
important to population and species survival in a changing environment
clones
a chart that shows all the possible combinations of alleles that can result from a genetic cross
pedigree chart
carries instructions to the next generation and determines phenotype
chromosomes
genes
a permanent change in the base sequence of DNA
asexual reproduction
reproduction involving only one parent (usually female) - offspring genetically identical to the parent and each other
reproduction involving two parents - offspring different to the parents
each homologous pair of chromosomes lines up at equator - maternal or parental - independently of other homologous pairs