YR10 Genetics - Topic Test 3 Flashcards
genotype
g e n
genetic information carried by an individual in pairs (pairs of genes or a combination)
phenotype
the way
the way characteristics/genotypes are expressed; observable characteristics of an individual (physical, visible)
heterozygous
homologous chromosomes
having two different genes on homologous chromosomes
homozygous
homologous chromosomes
having two identical genes on a homologous chromome
pure breeding
g e n
where all individuals have the same genetic information for a characteristic generation after generation
3 patterns of inheritance
dominant/recessive
sex-linked inheritance
incomplete dominance
sex-linked inheritance
x not y
sex-linked traits are ones that are inherited on the x-chromosome but not the y-chromosome.
e.g. haemophilia, colourblindness
trait
i c
inherited characteristics
allele
a l t
same point
alternative form of the same gene: e.g. eye colour (brown, blue)
they are located at the same point of homologous chromosomes
dominant
trait observed
1 allele
the trait that is observed in the outward appearance of a heterozygous individual
a characteristic that will always be observed when at least one copy of the allele is present
e.g. huntington’s disease
recessive
trait hidden
homozygous
the trait that can be hidden if the dominant gene is present. can only be seen in a homozygous condition.
e.g. cystic fibrosis
autosome
all chromosomes except the sex chromosomes
carrier
a person or other organism that has inherited a recessive allele for a genetic trait or mutation but usually does not display that trait or show symptoms of the disease.
incomplete dominance
expresses the two alleles but also blends the two traits.
co-dominant
expresses both alleles simultaneously but without any blending
chromosomes
structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
heredity
is the passing on of traits from parents to their offspring
asexual or sexual
mendel’s experiments
he experimented principles of inheritance because he…
Mendel did thousands of cross-breeding experiments.
Ignored all characteristics expect a few markedly contrasting ones which he studied
karyotype
an individual’s collection of chromosomes
true breeding
A true breeding is a kind of breeding where in the parents would produce offspring that would carry the same phenotype
pedigree
a diagram that depicts the biological relationships between an organism and its ancestors.
gamete
Gametes are an organism’s reproductive cells. They are also referred to as sex cells
