Genetics vocabulary
What do we call the basic unit of heredity that's is passed from parents to offspring?
Gene
Which type of trait is usually represented by a capital letter?
Dominant
What tool do we use to predict the possible outcomes of a genetic cross?
Punnet squares
Which term describes the genetic makeup of an organism?
Genotype
Probability is the chance that an event will do what?
Happen(or occur)
What term describes different forms of the same gene?
Alleles
Which trait will show up in the phenotype of a heterozygous organism?
Dominant trait
How many boxes are in a basic Punnett square for one trait?
4
Which term describes what you can see, like height or eye color?
Phenotype
What fraction represents a 50% chance?
1/2
What is the name for an organism that has two identical alleles
Homozygous
If brown eyes (B) are dominant over blue eyes (b), what eye color would a Bb individual have?
Brown eyes
If both parents are heterozygous (Bb × Bb), how many different genotypes are possible?
BB,Bb,bb
What is the genotype of an organism that is heterozygous for a trait?
One dominant and one recessive allele (example: Bb)
In a Bb × Bb cross, what fraction of offspring are expected to be heterozygous?
1/2(or 50%)
What do we call the physical appearance of a trait.
phenotype
Can a recessive trait appear if a dominant allele is present?
No
What percentage of offspring would show the recessive phenotype in a Bb × Bb cross?
25%
Can two organisms have the same phenotype but different genotypes?
Yes
If the probability of a trait is 25%, how many out of 4 offspring would you expect to show it?
1 out of 4
What term describes a gene that is expressed only when two copies are present?
Ressesive
Why can two parents with dominant phenotypes have a child with a recessive
Both parents can carry a recessive allele and pass it on to their child
A homozygous dominant parent is crossed with a homozygous recessive parent. What are the genotypes and phenotypes of all the offspring?
genotypes: all Bb
phenotypes: all show the dominant trait
Give two different genotypes that could result in the same dominant phenotype.
BB and Bb
A heterozygous tall plant (Tt) is crossed with a short plant (tt). What percentage of the offspring will be tall?
50% tall