Genetics exam for thurday Flashcards
What is a locus?
Position or place of the allele
What is an allele?
One of two or more alternative forms of a gene
What is a gene?
An inherited factor (encoded in the DNA) that helps determine a characteristic
What does hemizygous mean?
having only one copy of a gene or chromosome segment instead of the usual two.
What is autosomal?
Not on sex chromosomes, all other chromosomes
What is sex-linked
These traits are controlled by genes on the sex chromosomes, which are the X and Y chromosomes
What is a monohybrid cross?
a genetic cross that studies the inheritance of a single trait or gene in two organisms with different variations at a single genetic locus.
What is a dihybrid cross?
a breeding experiment that involves mating two organisms that are heterozygous for two traits.
What is a back cross?
a breeding technique in genetics that involves crossing a hybrid organism with one of its parents or a genetically similar organism. F1 gen X P
What is a test cross?
unknown genotype x homozygous recessive
what is a reciprocal cross?
The sexes of the parents are reversed.
What is nondisjunction?
the failure of chromosomes to separate properly during cell division (meiosis)
What is the principle of segregation?
Each diploid organism possesses two alleles for any particular characteristic. These two alleles segregate when gametes are formed, and one allele goes into each gamete.
What is the principle of independent assortment?
alleles located on different chromosomes will sort independently
What are the P, f1, and f2 generations in a monohybrid or dihybrid cross?
p = parents
F1= offspring of parents
f2 = offpring of f1 cross
What is the binomial expansion?
(n!/ X! * (n-x)! ) *p^x * q^n-x
p equals the probability of one event
q equals the probability of the alternative event
n equals the total number of events
What is the product rule?
the probability of two or more independent events occurring together is calculated by multiplying the individual probabilities of each event
What is XO sex determination?
XX is female and XO is male, male is missing the Y chromosome
What is XY sex determination?
XX is female and XY is male, present system in humans
What is ZW sex determination?
ZZ is the male and ZW is the female. The male is homogametic and the female is heterogametic.