Mendelian Genetics Flashcards
What is true breeding?
When offspring look like their parents
What is an allele?
A variation of a gene like eye color.
What is a dominant allele?
The allele that is expressed
What is a recessive allele?
The allele that is masked
What does it mean to be homozygous?
To have to of the same allele. Can be homozygous dominant or recessive
What does it mean to be heterozygous?
To have 1 of each allele. The dominant generally shows
What is a genotype?
The genetic make up. The genotype indicates the phenotype
What is the phenotype?
The physical appearance. You cannot know a genotype from a phenotype
What are Mendel’s laws of hereditary?
1) law of segregation-alleles separate during gamete production
2) law of independent assortment-alleles separate independently
What are Mendel’s 4 principles of inheritance?
1) genes have alternate forms
2) for each characteristic you have two alleles
3) an egg or sperm only has one allele
4) when the 2 alleles are different, one is shown and the other masked
What is a test cross?
Used to determine a genotype. Cross the unknown genotype with a homozygous recessive. If any offspring show a recessive trait the unknown was heterozygous
How does probability play a role?
Rule of multiplication-chance of two independent events at the same time
Rule of addition-chance of one event or another
What is a dihybrid cross?
A two trait cross (use the FOIL method)
What is intermediate inheritance?
When neither of the two alleles for the same gene dominate each other. Like white and red flowers making pink
What is co-dominance?
When both alleles are fully expressed. Like a roan horse
