Mendelian Genetics Flashcards
Who is Gregor Mendel?
Considered the, “Father of Genetics.” Conducted his most famous research by studying the frequency of traits in pea pods. He traced a trait through different generations of pea plants to determine which traits were dominant and which traits were recessive.
What are dominant traits?
The trait that is ALWAYS expressed. These traits are represented by uppercase letters.
What are recessive traits?
The trait that can be masked or hidden by the dominant trait. Only expressed when both alleles are the recessive form. These traits are represented by lowercase letters.
What does homozygous mean?
When an organism has two of the same allele like two dominant alleles or two recessive alleles. This organism is pure. Ex. RR or rr
What does heterozygous mean?
When an organism has two different alleles (one recessive and one dominant allele). This organism is hybrid. Ex. Rr
What is probability?
Probability= # of times an outcome occurs / # of all possible outcomes
What does the Chromosome Theory of Heredity state?
The idea that if two genes are on the same chromosome, and you inherit the whole chromosome, then you have to inherit those two genes (and whatever alleles they have) together.
What is a genotype?
The genes of an organism
What is a phenotype?
The visible traits or genes that are expressed in an organism
What is the difference between a genotype and phenotype?
You can’t observe an organism’s genotype, but you CAN observe its phenotype.
What is an allele?
One form (or variation) of a gene.
What is a punnet square?
A tool to figure out the probability that an offspring will express a certain trait.
What does a monohybrid cross help us discover?
A monohybrid cross is a single trait Punnet’s Square. It helps us predict the phenotype of offspring given the genotypes of two parents, for ONE trait.
TIP - “Mono,” means one.
What does a dihybrid cross help us discover?
A dihybrid cross is a double traits Punnet’s Square. It helps us predict the phenotypes of offspring given the genotypes of parents, but for TWO
traits.
TIP - “Di,” means two.
What must gametes contain?
Gametes must contain half of the alleles of the parent, and every trait must be represented in the gamete.
