A segment of DNA, located on a chromosome, that carries hereditary information.
100
Define “genotype”
The set of alleles that an organism contains in its chromosomes
100
Define “probability.”
The mathematical chance that an event will occur.
100
What is it called when phenotypes of two alleles blend?
Incomplete dominance
200
Define “heredity”
A set of traits an organism receives from its parents.
200
For each gene, how many alleles does an offspring receive from each parent?
One allele for that gene from each parent
200
Define “phenotype.”
The physical form displayed by the organism.
200
How is probability expressed?
Probability is expressed as a ratio, a fraction or a percent.
200
Give an example of incomplete dominance.
A red snapdradon crossed with a white snapdragon to produce pink snapdragons.
300
Define “trait”
A characteristic that an organism can pass on to its offspring.
300
Define “allele.”
Different forms of the same gene.
300
Being homozygous for a trait means:
Being homozygous for a trait means having two of the same allele.
300
What does a Punnett Square show?
All the possible combinations of alleles from the parents
300
What happens in codominance?
An organism with both alleles displays both phenotypes at the same time.
400
Mendel started his experiments with true-breeding plants. Define “true-breeding plant.”
A plant that always produces offspring with the same form of a trait when it self-pollinates.
400
Define “dominant allele”
The form of a gene that when present, covers up the appearance of a recessive allele.
400
Being heterozygous for a trait means:
Being heterozygous for a trait means having two different alleles for the same gene.
400
What is the probability of two heterozygous right-handers having a left-handed offspring? Draw a Punnett square for it!
Possible genotypes are:
RR, Rr, Rr, and rr.
25% chance of a left-handed offspring.
400
There are three (3) alleles for human blood type. Which are codominant and which is recessive?
Type A and B are codominant, and type O is recessive.
500
What is cross-pollination?
When the pollen from one plant is used to fertilize another plant.
500
Define “recessive allele.”
The form of a gene that is not expressed unless the organism inherits it from both parents.
500
Give two different words to describe the genotype Bb.
Heterozygous, Hybrid
500
What is the probability of a homozygous black rabbit and a brown rabbit having brown offspring? Black is dominant, and is B; brown is recessive and is b.
Homozygous black rabbit is BB.
Brown rabbit is bb.
All their offspring will be Bb. 0% chance of brown offspring.
500
Parakeet color is an example of what type of trait?
A polygenic trait because it is determined by more than one gene.