Genetics Flashcards
What is Blending Inheritance
and is that how inheritance works?
It was a theory that traits in offspring are a blend of the two parents
Blending was disproven by Mendell’s experiment
What’s so special about the garden with pea plants and what was the name of the monk who studied them?
Gregor Mendel looked at the pea plants for the pattern of inheritance for multiple traits.
His study disproved the theory of “blended” inheritance.
What did Mendel do in the experiment?
He took the pollen from the male purple plants and pollinated female white flowers and observed the color of the offspring.
- P generation (parent)
- F1 generation (1st gen)
- F2 generation (2nd gen)
Did Mendel’s work support or disprove blending?
Traits are inherited as units - this disproves blending
What happened in Mendel’s experimental cross?
Hint:
P gen
F1 gen
F2 gen
- P gen -purebred purple
- F1 gen - recessive white traits hidden, all flowers still purple
- F2 gen - white traits reappeared 3:1
What is heredity?
(2 things)
- Heredity is passing of traits to the next generation.
- It is the key to differences between species AND within a species
Alleles are different forms of what?
What we learned because of Mendel:
Alleles are what?
Dominant means what?
Recesive means what?
- Alleles are different forms of a gene.
- Characteristics of the dominant allele will show up regardless.
- Characteristics of the recessive allele will show up only when with another recessive allele.
What does genotype mean?
~ It’s an organisms’s allele pairs.
~ It’s what’s going on in the genes.
ex. Hh Pp Rr
What does phenotype mean?
~ It’s the observable or outward expression of the allele pair.
~ It’s what you physically see.
(Webbed feet, rolled tongue)
What is gene location?
It’s the specific area on a chromosome where a
particular characteristic is located.
What does homozygous mean?
There are two of the SAME allele for a trait.
(examples: HH or hh)
What does heterozygous mean?
There are two DIFFERENT allels for a trait.
(example: Hh)
What does a Punnett Square determine?
It’s a tool to determine the probability of
a trait
being passed
to offspring.
What is the difference between a monohybrid cross
and a dihybrid cross?
A monohybrid cross looks at one trait;
a dihybrid cross looks at 2 traits.
What are the ratios in a punnet square?
PR:
GR:
PR: phenotypic (What you see.)
GR:. genotypic (allele pairs)
RATIO must be numbers!
example: 1:2:1
or
3:1
What is a dihybrid cross
and where are the genes located?
- Crosses that involve two traits (ex: pod color & pod shape)
- Genes must be located on non homologous chromosomes.
A pedigree is a map of……
It traces………
It’s a map of genetic inheritance.
It traces 1 (ONE) trait through multiple generations.
The trait can be EITHER dominant or recessive.
