Mendelian Genetics Flashcards
What is the study of genes and how they transfer traits from parent to offspring called?
Genetics
Genetics is a fundamental area of biology that explores heredity and variation in organisms.
What do you inherit from your parents?
Traits
You inherit half of your chromosomes from your mother and half from your father.
Who is known as the Father of Genetics?
Gregor Mendel
Mendel was an Austrian monk who used pea plants to study inheritance patterns.
What are the two laws established by Mendel?
- The Law of Segregation
- The Law of Independent Assortment
What is a gene?
A region on the chromosome that codes for a trait in an organism
Example: The gene that codes for hair color.
What is an allele?
A trait that is coded for by a gene
Example: The allele for purple flowers.
What is a dominant allele/trait?
The trait that is expressed in an organism that carries it
Symbolized by a capital letter (e.g., P for purple flowers).
What is a recessive allele/trait?
The trait that is not expressed in an organism that carries both alleles for a character
Symbolized by a lowercase letter (e.g., p for white flowers).
What does F1 generation refer to?
The offspring produced by the parent generation
Subsequent generations are numbered F2, F3, etc.
What is a genotype?
The alleles that an organism inherits from its parents
Example: Pp, PP, pp.
What is a phenotype?
The way a character appears as a result of its genotype
Example: Genotype PP = phenotype purple flowers.
What does homozygous mean?
Organism that has inherited the same variant of allele from its parents
Example: PP or pp.
What does heterozygous mean?
Organism that has inherited different alleles for the same character
Example: Pp.
What is a monohybrid cross?
A cross examining one character
It can be represented using a Punnett square.
What is a test cross?
A method to determine an organism’s genotype by crossing it with a homozygous recessive
It helps reveal the dominant or recessive traits.
What is the Principle of Dominance?
Some alleles are dominant and some are recessive
Dominant alleles are expressed if present; recessive alleles are expressed only when no dominant alleles are present.
Fill in the blank: The dominant allele for flower color is represented as _____ and the recessive allele is represented as _____.
P, p
What phenotype does a homozygous recessive genotype exhibit?
Recessive phenotype
A recessive phenotype shows up only if the genotype is homozygous for that allele.
True or False: A heterozygous genotype will always express the recessive phenotype.
False
The dominant phenotype is expressed in a heterozygous genotype.
What trait is determined by the dominant allele T?
Ability to curl the tongue in a U-shape
This is an example of a single allele trait.
What are the phenotypes for the genotypes PP, Pp, and pp?
- PP = purple flowers
- Pp = purple flowers
- pp = white flowers
