2.3 Monohybrid and Dihybrid Crossing Flashcards
What is a monohybrid cross?
two pure individual parental strains are mated that contrast only in the trait that is being observed
What is self-fertilization or “selfed”?
when the parents plant mates with “itself” and always produces offspring with its own trait
In genetics what does P1 refer to?
the original parental generation
What does F1 refer to?
the first filial generation
first set of offspring from the P1
What does F2 refer to?
the second filial generation
second set of offspring from the P1
What is a reciprocal cross?
when crosses are made with either parent being the pollinator/male or being pollinated/female (not sex-dependent)
What is Mendels First Postulate?
- genetic characteristics are controlled by unit factors existing in pairs in individual organisms
What is a unit factor?
controls the genetic character of an organism
How do unit factors exist in organisms?
in pairs
What is Mendels Second Postulate?
when two unlike unit factors responsible for a single characteristic are present in a single individual, one unit factor is said to be dominant to the other, which is said to be recessive
What is Mendels Third Postulate?
during the formation of gametes, the paired unit factors separate, or segregate, randomly so that each gamete receives one or the other with equal likelihood
What does phenotype refer to in modern genetics?
physical manifestation of any trait
What are unit factors known as in modern genetics?
genes
What is the definition of a gene?
unit of hereditary that is transferred from a parent to an offspring and is held to determine some characteristic of the offspring
What is an allele?
variations of a given gene
How is a dominant and recessive trait represented in Mendelian genetics?
dominant = capital letter
recessive = lowercase letter
What is the genotype of a given trait?
consists of the two alleles inherited for a particular gene
What does homozygous for a trait mean?
individual has two alleles that are the same
What does heterozygous for a trait mean?
individual has two different alleles for a given trait
What can a Punnett square be used to visualize?
monohybrid cross
