Exam 1-Genetics Flashcards
(67 cards)
What is genetics?
The study of heredity - how traits are passed from parent to offspring.
What are traits?
Anything that you inherit from your parents, e.g., hair color, freckles, dimples.
Who is considered the Father of Genetics?
Gregor Mendel.
What did Gregor Mendel study to discover the laws of heredity?
Pea plants.
When was Mendel’s work rediscovered?
In 1900.
What is a trait?
A genetically determined variant of a characteristic, e.g., white flowers vs purple flowers.
What does P1 generation refer to?
The parent generation.
What does F1 generation refer to?
The first filial generation, the offspring from the P1 generation.
What does F2 generation refer to?
The second filial generation, the offspring from the F1 generation.
Define a dominant trait.
The trait that is expressed more often.
Define a recessive trait.
The trait that is expressed less often because it is covered up by the dominant trait.
What is a gene?
The segment of DNA on a chromosome that controls a particular trait.
What is an allele?
The different forms of a gene, represented by letters (lower case and capital).
What is the probability of an event?
The likelihood that a specific event will occur.
What is a genotype?
The set of alleles that an organism has, represented by a combination of letters.
What is a phenotype?
An organism’s physical appearance.
What does homozygous mean?
When the two alleles for a particular gene are the same.
What does heterozygous mean?
When the two alleles for a particular gene are different.
What is a Punnett Square?
A diagram that predicts the expected outcome of a genetic cross by considering all possible combinations of gametes.
What is a monohybrid cross?
A cross involving a single trait.
In a Punnett Square, what is represented by ‘R’ and ‘r’ in seed shape?
R represents round seeds and r represents wrinkled seeds.
What is incomplete dominance?
When the phenotype of the offspring is in-between that of the parents.
Give an example of incomplete dominance.
Four O’Clock flowers: Red flower + White flower = Pink flower.
What is codominance?
When both alleles for a gene are expressed in a heterozygous offspring.