Genetics
Unit 3.2
Meiosis
is the process of reduction division in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell
haploid and diploid
haploid= 1 set of chromosomes "gamete" (in a human n=23)
- haploid is an egg without its mate
diploid= 2 sets of chromosome "normal" ( in humans 2n=46
- diploid is anything sexually produced
homologous chromosomes
are chromosomes that have a corresponding chromosomes from the opposite sex parent ( for the same trait)
- homologous means same trait
crossing over
is an exchange of portions of chromatids genetic material between 2 homologous chromosomes
mendelian genetics
genotypes and phenotypes
- Genotypes are the sets of alleles
- phenotype is the physical expression of the set of alleles
- alleles- is one of a number of of alternative forms of the same gene or same genetic locus
Examples
Aa x Aa phenotype- 3 tall, 1 short hybrids= Aa/Aa
genotype- 1 AA 2 Aa 1aa per-bread= AA/aa
AA= tall 1 to 2 to 1 ratio
Aa= tall punnett square F1= offspring
aa= short
If there are dominates the big letter will be what happens
a tall allele will be dominate
probability
is the likelihood of an event occurring
- gamete formation is random use probability to predict
- use a punnett square to predict outcomes of a cross
F1 anf F2
If ever asked to do F2, F1 has to have homozygous alleles so all the outcomes are the same to began F2 phase