Family Level Inheritance Flashcards
What is a heterozygote?
cell has 2 different alleles
What is a homozygote?
cell has 2 of the same alleles
What is the Blending Theory of Inheritance?
it suggests that hereditary traits bland evenly in offspring from mixing of the 2 parents
What is a monohybrid?
heterozygote for a single trait
What is a dihybrid?
zygote produced by a cross with 2 characters
What is independent assortment?
alleles that govern 2 characters segregate independently in a 9:3:3:1 ratio of 2 dominant : 1 dominant : other dominant : both recessive
What are autosomes?
chromosomes other than the sex chromosomes
What are the 2 main traits of the SRY gene?
- it is on the Y chromosome and becomes active after 6-8 weeks
- it signals the development of male assets
Why does sex linkage occur?
because of the 2 differences between males and females
What are the 2 differences between males and females/
- Males have 1 copy of the X chromosome and females have 2
2. Males have a Y chromosome and females do not
What is a pedigree?
chart showing parents, grandparents and offspring and whether or not they have a certain trait
What is a Barr body?
dense mass of chromatin which is created when one of the X chromosomes are inactivated
What is the product rule?
independant probabilities multiplied
What is the sum rule?
add up all the individual probabilities
What is a Punnett Square?
method to determine crosses
What is a test cross?
a cross between dominant and recessive phenotypes
What is incomplete dominance?
dominant and recessive alleles bland so they both show in heterozygous individuals (Ex. white X red = pink)
What is co dominance?
alleles have the same dominance so they are equally visible
What are multiple alleles?
when more than 2 alleles for the same gene, 1 individual can only carry 2 alleles but other alleles can exist outside of the individual (Ex. blood types)
What is epistasis?
gene with 1 or more allele interact on the locus resulting in genes at different locus being masked or inhibited
What is polygenetic inheritance?
several genes contribute to the same character
What is pleiotropy?
single gene affects more than one character
What are linked genes?
genes on the same chromosome that follow “linkage”
