Cutie
Why did Mendel choose pea plants to study?
It was easy to cross plants to observe offspring, characters were easy to observe, & characters had at least 2 identifiable traits
What is a phenotype?
The physical appearance of an organism
What is a recessive trait?
A trait hidden by a dominant one
If a plant has simple dominance and the genotype Pp, would it express the dominant trait, the recessive trait, or both?
This plant would express the dominant trait.
What are multiple alleles?
When a gene has more that 2 possible alleles
What is the difference between multiple alleles & polygenic inheritance?
Multiple alleles have more than 2 alleles for a particular trait.
Polygenic inheritance involves multiple genes to produce a trait.
How are alleles for the dominant trait represented?
They are represented by a Capital Letter.
Alleles are different forms of genes that result in different traits
What is incomplete dominance?
Incomplete dominance occurs when 2 traits produce a blended phenotype.
What is polygenic inheritance?
Occurs when 2 or more genes interact to produce a single trait
If fox population moved to a desert location, which feature would you most likely see passed on future generations?
Larger ears are an adaptation that would help individuals survive longer. Over time you'd see an increase in the population of long eared foxes.
When you cross homozygous parents with different traits (one PP & one pp) what do you expect from the offspring?
All offspring will be heterozygous Pp and will display the dominant trait
What determines an organisms phenotype?
The genotype determines the phenotype
What is simple dominance?
Simple dominance occurs when a trait is controlled by only 1 gene that has 2 alleles.
1 allele will always be expressed if it is present.
What is codominance?
Occurs when both traits are present in the offspring WITHOUT blending.
Give an example of codominance
Codominance occurs when 2 alleles are both expressed. An example would be if you crossed a black horse & a white horse & got offspring with BOTH black & white hairs.
If a heterozygous Tt is crossed with tt, what genotypes would you expect in the offspring?
50% Tt and 50% tt
What are some examples of polygenic inheritance in humans?
skin color, height, & intelligence
Can natural selection result in evolution?
NO-natural selection doesn't create new DNA, it only affects existing traits already programmed into the cell.
It can produce variety, but it doesn't produce new kinds of organisms.
Where is the genotype of the mother located on the punnett square?
The mother's information is located across the top of the square
In human blood there are 3 alleles: A, B, i. If one parent contributes an A allele & one parent contributes a B allele, what blood type will the offspring have?
The offspring will have blood type AB since A & B are codominant.
How can you tell which trait is recessive if you cross 2 purebred parents with different traits?
The recessive trait will be the one that does not show up in the phenotype of any of the offspring.
What do boxes in punnett square represent?
They represent the possible genotypes and the probability of having a certain genotype.
What is natural selection?
Natural selection is the process by which organisms with certain adaptations survive to pass on their traits to a greater number of organisms.
When looking at a punnett square, how can you tell if you have codominance or incomplete dominance?
CODOMINANT alleles are CAPITALIZED.
incomplete alleles are lower case.