Lab 5 Flashcards
What are the two original parents represented by in a cross?
The offspring?
The offspring resulting from a cross between the two offspring
OG- P1
Offspring- F1
Offspring of F1- F2
Difference between genotype and phenotype?
Geno- genetic makeup of organism, the alleles Rr GgHH
Pheno- physical appearance for a trait
What are frequencies in genetics?
The proportion of one thing to the rest of the population
Frequencies are ratios that add up to 1
What is a ratio in genetics?
Proportion of one thing to another
separated by colons
Lowest number in series is 1
What is a monohybrid cross?
Between two organisms that differ with respect to one characteristic (two letters of same letter- Dd)
What is mendels first law?
It is the principle of segregation
States that alleles of one gene segregate from one another during the formation of gametes
Basically Punett square they split up
What is a dihybrid cross?
Between two organisms that differ with respect to two characteristics
Ex GgHh
How do you determine the type of F1 gametes?
Say you’re given AaBb
AB, Ab, aB, ab
Cross all possible outcomes
A a B b
What is mendels second law?
States alleles of different genes assort independently of one another during gamete formation
Ex: gametes of RrYy are RY Ry rY ry
When creating a chromosome diagram for a dihybrid what should you be careful of?
Make sure that the resulting gametes are correct like AB Ab aB ab
Two different possible arrangements
What is a test cross?
Involves crossing an individual of unknowns genotype with a homozygous recessive individual.
The homozygous recessive individual contributes only recessive alleles to any offspring from the rest cross which makes it easier to find the unknown genotype
How does Gene linkage work?
Of two different genes are in the same chromosome then gene linkage occurs
Must use the two alleles on the same gene as potential gametes
What is the reasoning behind two crossed over genes rarely occuring? Or frequently occuring?
It’s like a blond guy chopping a stick, of the genes are far apart there’s a better chance he’ll cut between and they’ll cross over
So if the cross over genes occur rare then they must be close together in the chromosome
Do practice problems on pages 111-113
Okay!
