L1: DNA and variation Flashcards
What is a trait?
A physical characteristic
What is a phenotype?
A physical characteristic
What is a variation?
Differences between members of a population is a called variation eg. height
What are the 3 causes of variation?
1) Environmental
2) Inherited: caused by your DNA
3) Both: inteaction of the two (eg. weight, height)
What is a gamyte?
A sex cell which is half the usual number of chromosones
What is a zygote?
A fertilised egg produced when the nuclei of the male and female gametes fuse in sexual reproduction
What are recessive and dominants genes?
A dominant allele is one that overrules the recessive of, resulting in the inheritance of the dominant gene
What is homozygous?
have the same two alleles of a particular gene
What is heterozygous?
having two different alleles of a particular gene
How many pairs of chromosones are there?
23 pairs
What does the last pair determine?
Sex of the offspring
What 2 functions does DNA have?
1) Genetic material
2) Hereditary material
What is a allele?
A version of gene. Each chromosone in a pair carries the same gene, but may have different alleles
What is sexual reproduction?
A form of reproduction that involves the fusion of male and female gametes.
What is asexual reprodution?
A form of reproduction that only involves a single parent and creates a gentetically identical offspring
