Genes Flashcards
Phenotype
The physical trait that an organism displays (such as hair colour)
Genotype
The genetic makeup, that allows an individual to have a certain trait (a certain gene for blue eyes)
Allele
A variation of a gene
2 main categories of genes
Dominant and Recessive
Dominant gene
The gene that is expressed by an organisms offspring
Recessive gene
The gene that is not displayed by an organisms offspring
The 4 bases of DNA
- Adenine
- Thymine
- Cytosine
- Guanine
How many chromosomes are usually in a human being?
46
How many pairs of chromosomes are usually in a human being?
23
How many chromosome pairs are sex chromosomes?
1
Punnet Square
A diagram that shows the probability of each genotype and phenotype in an offspring.
Autosomes
Body chromosomes that make you human ( non sex, First 22 pairs )
Sex Chromosomes
XX or XY ( 23rd pair ), determines the sex of the offspring
Genome
The complete set of genetic instructions for an organism
How many alleles do you need per trait?
2