Chapter 9 Genetics Flashcards
What does “true breeding” mean?
Repeated self-fertilization always yields the same phenotype
A fly has small wings (vv) and a black body (bb). What is it’s phenotype?
black body, small wings
If we did a cross ad expected to see 25% of each possible phenotype and we instead saw that 90% were of two of the types and only 10% were the other two, what can we tell about these genes?
They are linked
If you mate a hairy plant with a smooth plant and obtain a slightly hairy plant, this an example of ______?
Incomplete Dominance
If the distance between genes P and Q is 30 units, the distance between P and Y is 20 units, and the distance between Q and Y is 10 units, which gene is between the other two?
Y
IF two alleles are both expressed in the presence of each other, they are ______?
Codominant
What is polygenic inheritance?
One trait, many genes
Genetics
The study of how traits are passed down from generation to generation
True or False - A Punnett square will always tell you exactly how many offspring of each type to expect from a cross.
False - it provides the probability of a particular outcome
The Generation resulting from mating the P Generation
F1
You are crossing GgHh x gghh. What goes on the sides of the Punnett Square?
One side GH, Gh, gH, gh; other side: gh
Principle of Independent Assortment
Alleles of different genes assort randomly with respect to each other.
Which more reliably characterizes a probabilistic process like inheritance; large samples or small samples?
Large Samples
Statistical Test
A method of determining if a particular experimental result matches a Punnett square prediction closely enough to be attributed to chance.
When you see a trait which varies continuously from very small to very large within a population, this is most likely a ______?
Quantitative (polygenic) traits
In a cross where we expected to see equal representation of all four possible phenotypes, we observed; 5 rough purple, 45 rough red, 45 smooth purple, 5 smooth purple. Which are the parental types?
Rough red and smooth purple
In a cross where we expected to see equal representation of all four possible phenotypes, we observed: 5 rough purple 45 rough red 45 smooth purple 5 smooth purple What is the recombination frequency?
10%
How many copies of each gene on the x chromosome does a male human have?
One
Is an individual with a “tt” genotype homozygous or heterozygous?
Homozygous
Why would you do a test cross?
To determine the genotype of an unknown which has a dominant phenotype
If the chance of being tall was 1/3 and the chance of being green-eyes is 1/3, what is the chance of being tall OR green-eyed?
2/3
How can you identify a sex-linked trait?
Disproportionate effect on one gender
If two individuals don’t have a trait, but their offspring does have the trait, is the trait dominant or recessive?
Recessive
The chromosome theory of inheritance combines two different ideas…What are they?
Mendel’s genetic work with movement of chromosomes during cell division
