Mendel & His Experiments
The scientist known as the father of genetics.
Who is Gregor Mendel?
The physical expression of a trait.
phenotype
This law states that allele pairs separate during gamete formation.
law of segregation
A cross that examines one trait.
monohybrid cross
The genotype that always expresses the recessive phenotype.
homozygous recessive
The organism Mendel studied because it showed clear, heritable traits.
pea plants
The genetic makeup of an organism.
genotype
This law applies when genes are located on different chromosomes.
the law of independent assortment
A cross used to determine an unknown genotype.
test cross
Recessive traits may do this in pedigrees.
skip generations
Mendel controlled reproduction in peas using this structure.
Flowers
An organism with two identical alleles for a trait.
homozygous
The stage of meiosis when alleles separate.
anaphase 1
A Punnett square predicts this, not guaranteed outcomes.
probability
A heterozygous genotype and this genotype share the same phenotype.
homozygous dominant
Mendel concluded traits are inherited as these discrete units.
genes
An organism with two different alleles for a trait.
heterozygous
Each gamete receives this many alleles per gene.
one allele
A cross between TT and tt results in offspring that are all this genotype.
heterozygous
The genotype ratio from a heterozygous × heterozygous cross
1:2:1
The generation produced by crossing two true-breeding parents.
the F1 generation
An allele that is expressed whenever it is present.
dominant allele
A major exception to independent assortment.
genetic linkage
Mendel’s ratios only hold true when sample size is this.
large
Two heterozygous parents produce offspring with this probability of recessive phenotype.
25%