Unit C2 - Genetics Flashcards
What is the definition of Heredity?
The passing of traits from parents to offspring.
What are genes?
Units of heredity and are located on chromosomes.
who is the “founder of Genetics?”
Gregor Mendel
What experiment is Gregor Mendel known for?
The garden peas experiment.
What is self-fertilization within a plant?
Pollen produced by male stamen attaches to the pistil inside the flower.
(where the plant creates a clone of itself)
What does cross-fertilize mean?
the combining of male and female sex cells of different plants.
What does P Generation mean?
The parent generation
what does F1 mean?
the first filial generation
(first-generation of children)
What is the difference between recessive and dominant alleles?
Only the dominant one is shown when a dominant and a recessive allele are paired.
DD = Dominant, dd = recessive, Dd = Dominant (IS SHOWN)
What are Mendel’s Laws of Heredity?
- Inherited characteristics are controlled by factors (known as genes) that occur in pairs
- Principle of Dominance → One factor/gene masks the effect of another
- Mendel’s Law of Segregation → A pair of factors/genes separate and segregate during the formation of sex cells (meiosis)
A dominant gene is indicated by a _____ letter and will be ____ expressed in heterozygous form, in notation, it will be written ___.
Upper-case, always, first (e.x. Dd)
(WHEN THERE IS A DOMINANT ALLELE PRESENT, IT IS ALWAYS EXPRESSED)
A ressesive gene is indicated by a _____ letter and will be ____ expressed in heterozygous form, in notation, it will be written ___.
Lower-case, never, last (e.x. Dd)
What are Alleles?
Two or more alternate forms of a gene.
Dd
What is a Genotype?
The genes that an organism contains for a particular trait
(DD,Dd,dd)
What is the Phenotype?
The observable traits of an individual.
DD → Dominant trait
Dd → Dominant trait
dd → Recessive trait
What is the definition of Homozygous?
A genotype in which both genes are identical
(e.x. DD & dd)
What is the definition of Heterozygous?
A genotype in which both genes are different
(e.x. Dd)
What are other words for a Homozygous offspring?
A pure or true breed.
What are other words for a Heterozygous offspring?
A hybrid or carrier.
What is a monohybrid cross?
A cross between two organizations, following the inheritance of one trait.
(e.x. crossing pea plant height, and not height and colour)
What is used to find the possible combinations of alleles in offspring?
The Punnett Square
Does genetic crossing talk about probabilities or absolutes?
(does having four babies exactly match all the combinations)
Probabilities.
what is a test cross?
A test that is performed to determine the unknown genotype of an organic that has a dominant phenotype.
What do you test in a test cross?
a recessive genotype with an unknown genotype with a dominant phenotype (rr & R__)
