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__)
What is incomplete Dominance?
When two genes are equally dominant, they interact to produce a blend of the two.
What is Codominance?
When both genes are expressed at the same time.
What are the alleles for the genes that lead to A, B and O blood type
I^A, I^B, i
With multiple alleles (more than 2) how do you define them?
You have to use the same capital letters and superscript numbers.
What are the alleles for the genes that lead to Rh+ and Rh- in human blood?
R & r respectively
What is the phenotype ratio for a dihybrid cross with two heterozygous genotypes?
9:3:3:1
Both dominant are expressed → to no dominant genes expressed
when you have different chances from separate independent events, how can you find the overall probability?
You multiply them together to get the overall probability.
What are Polygenic Traits?
Inherited traits that are affected by more than one gene.
What are Epistatic Genes?
Masks the expression of other genes.
What is a complimentary interaction?
When two different genotypes interact to produce a phenotype that neither is capable of producing itself.
