Advanced Genetics Flashcards
(28 cards)
What is a gene?
Considered the basic unit of inheritance, passing from parents to offspring and containing the information needed to specify physical and biological traits. Made up of DNA.
What do genes act as instructions for?
To make molecules called proteins, many genes don’t code for proteins. Instead, they help control other genes
What is an allele?
•One of two or more versions of a DNA sequence (a single base or a segment of bases) at a given genomic location.
•A variant of a gene for a trait
How many alleles does an individual inherit for any given genomic location?
Two alleles, one from each parent.
What does it mean if an individual is homozygous?
•Having inherited the same versions (alleles) of a genomic marker from each biological parent (has two identical versions of that marker)
•If two alleles are the same, the individual is homozygous for that allele
Define heterozygous.
Describes having two different versions of the same gene inherited from the mother and father.
What is a dominant trait?
•A trait that will appear in the offspring if one of the parents contributes it.
•If present, it will always be expressed
What is a recessive trait?
A trait that must be contributed by both parents to appear in the offspring.
What is a genotype?
The genetic makeup of an organism, describing its complete set of genes.
What is a phenotype?
An individual’s observable/ physical traits, such as height, eye color, and blood type.
What does Mendel’s Law of Dominance state?
•Some alleles are dominant over others for a given gene; non-dominant traits are termed recessive.
•If an organism inherits one dominant variant then it will display the effect or phenotype of the dominant allele
What is the Law of Segregation?
States that two alleles for each gene separate during gametogenesis so that the parent may only pass one allele to the offspring.
What does the Law of Independent Assortment state?
The alleles of different genes segregate independently during gametogenesis.
What is a monohybrid cross?
A cross involving a single characteristic trait where crossing two homozygous traits creates a heterozygous trait.
What is the parental generation in genetics referred to as?
P generation.
What is the first generation of offspring called?
Filial generation or F1.
What is a dihybrid cross?
Inheritance of two different traits across two organisms that are both heterozygous for those traits.
What is the expected phenotypic ratio from a dihybrid cross?
9:3:3:1.
Fill in the blank: A trait that always appears in the offspring if one parent contributes it is called _______.
dominant.
Fill in the blank: An individual who has two identical versions of a genomic marker is termed _______.
homozygous.
True or False: A recessive trait can be expressed if only one parent contributes it.
False.
What is the definition of co-dominance?
Co-dominance is a genetic scenario where two different alleles are expressed equally in the phenotype.
What does it mean when two alleles are present at the same time?
When two alleles are present at the same time, they can interact in various ways, such as co-dominance or incomplete dominance.
What is an example of co-dominance?
Example: In a flower, red and white alleles may produce a flower with both red and white patches.
