Genetics Flashcards
(23 cards)
Law of dominance:
in a heterozygote, one trait will conceal the presence of another trait for the same characteristic
Law of independent assortment:
The alleles of two more genes get sorted into gametes independently of each other. The allele received for one gene does not influence the allele received for another gene.
Law of segregation:
when an organism creates gametes (like sperm or egg cells), the two alleles (versions of a gene) for a trait separate, so each gamete receives only one allele.
Incomplete Dominance
Heterozygote is a blend
Mulitple Alleles
More than 2 alleles per trait
Codominance
phenomenon in which two alleles (different versions of the same gene) are expressed to an equal degree within an organism. As a result, traits associated with each allele are displayed simultaneously.
Polygenic Traits
Many Genes = Single Trait
Ex: Skin Color, Human Height
Epistasis
- A single gene codes for many traits
- Ex: Red hair in humans
Non-Nuclear Inheritance:
DNA is found in Mitochondria
What is the relationship between DNA and genes?
- Genes are sections of DNA
- Genes are found on your chromosomes
- Genes are inherited from your parents
What is an allele?
a form of a gene represented by a letter
What is the genotype of an organism?
Its genetic make-up (or DNA sequences), to keep it simple, THE LETTERS on the worksheet
What is the principle of dominance?
That one trait is dominant, and one is recessive
What is a complex trait?
a trait that has many other traits contributing to the phenotype
How do mutations occur?
a mistake in the copy of the allele
How many possible gametes can each parent have in a dihybrid cross?
4
In a dihybrid cross, how many boxes does a Punnett Square have?
16
How to calculate the number of boxes in a Punnett Square for a dihybrid cross?
4 possible gametes X 4 possible gametes
What are gametes?
Sex cells (haploid cells).
Which pair of chromosomes is the sex chromosomes in humans
23
What is a gene?
A segment of DNA found on chromosomes is used to carry instructions for our traits.
Gene expression is
When the instructions from genes are used to make proteins.
What is autosomal dominance?
When one allele completely overrides another allele in the phenotype.
