topic 7 Flashcards
genotype
genetic constitution of an organism
phenotype
expression of genetic constitution and its interaction with the environment
alleles
variation of particular gene on same locus arise by mutation (changes in base sequence)
how many alleles of a gene can be found in a diploid organism
2 as diploid organism have two sets of chromosomes
but there may be many alleles of a single gene in population
Homozygous
Alleles at a specific locus are the same
Heterozygous
Alleles at a specific locus are different
Mono hybrid cross
Inheritance of one phenotypic characteristic coded for by a single gene
Dihybrid cross
Inheritance of 2 phenotypic characteristics coded for by 2 different genes
Sex linked gene
A gene with a locus on a sex chromosome
How does autosomal linkage affect inheritance of alleles
2 genes located on same autosome (non sex chromosome)
So allele on same chromosome inherited together and stay together during independent segregation of homologous chromosome during meiosis
But crossing over between homologous chromosome create new combos of allele
Population
Group of organisms of the same species in one area at one time that can interbreed
Gene pool
All the alleles of all the genes in a population at one time
What does hardy Weinberg principal state
Allele frequency will not change from generation to generation :
If population large
No immigration
No mutation
No selection
Mating is random
Evolution
Change in allele frequency over time occurring through the process of natural selection
Factors that may drive natural selection
Predator disease and competition for means of survival
Leading to differential survival and reproduction
