What type of selection is this? Can you give an example
Stabilising
Describe Homozygous.
The same form of the allele is present in the genotype e.g. HH, hh
What is sexual reproduction?
Reproduction involving two parents. Produces genetic variation.
What is heterozygous?
Different forms of the allele are present in the genotype e.g. Hh
What is a pedigree chart?
A diagram that depicts the biological relationships between an organism and its ancestors
What is genetic diversity?
A measure of the different genetic combinations within a gene pool
What is migration?
Movement of organisms into (immigration) and out (emigration) of a population.
What is a physiological adaptation?
Internal adaptations to an animal such as chemical, biochemical, metabolic or cellular. Examples include venom production, multiple stomachs
What is founder effect?
The loss of genetic variation when a new population is established by a very small number of individuals from a larger population.
What is a test cross?
A genetic cross between a homozygous recessive individual and a corresponding suspected heterozygote to determine the genotype of the latter.
What is independent assortment?
The way the homologous chromosomes line up at the equator maternal and paternal, is completely random
What is Phenotype?
The physical appearance of the organism
Name the process: The process that occurs during meiosis where pairs of alleles are separated when the homologous chromosomes split
Segregation
What is an allele?
Different forms of a gene due to slightly different order of bases e.g. brown eyes and blue eyes
What is population bottleneck?
An event that drastically reduces the size of a population. It may be caused by various events, such as an environmental disaster.
What is selection pressure?
Environmental factors that influence the survival and reproductive success of individuals within a population.
What is a mutation?
A permanent change in the bases on DNA. It is the only way of creating new alleles
What is a genotype?
The genetic make-up of the organism
What is evolution?
Is the change in the characteristics of a species over time and relies on natural selection.
What is natural selection?
The process by which heritable traits increase an organism's chances of survival and reproduction.
What type of selection is this? Can you give an example
Directional
What is a structural adaptaion?
Differences in how different organisms look like. For example, fur, feathers, webbed feet, long beak etc
What is a gene?
A length of DNA that holds the instructions for a characteristic
Somatic cell
Body cells. If a mutation occurs in these cells, it will not be passed on to offspring.
What is Allele frequency?
A measure of the relative frequency of an allele on a genetic locus in a population.
What is asexual reproduction?
Reproduction involving only one parent. Doesn’t produce genetic variation.
What type of selection is this? Can you give an example
Disruptive
What is crossing over?
During meiosis, when the homologous chromosomes line up at the equator, they can exchange genetic information.
What is meiosis?
The type of cell division which produces gametes
What are homologous chromosomes?
Chromosome pairs (one from each parent) that are similar in length, gene position, and centromere location.
What is pure breeding?
A group of identical individuals that only produce one type of gamete due to the fact they are homozygous
What is a behavioural adaptation?
How different organisms act. For example: mating behaviours, migration, etc
What is fertilisation?
The union of male (sperm) and female (ovum) gametes to produce a diploid zygote in reproduction
What is a gamete?
Sex cell of an organism e.g. sperm, egg, pollen or ova