Week 7 Flashcards
(11 cards)
Q1: What is a gene?
A1: A gene is a segment of DNA that carries the instructions for making proteins or RNA, determining specific traits.
Q2: What is an allele?
A2: An allele is a variant form of a gene. Organisms typically have two alleles for each gene, one from each parent.
Q3: What is the difference between dominant and recessive alleles?
Dominant allele: Only one copy is needed to express a trait. Represented with an uppercase letter (e.g., “A”).
Recessive allele: Two copies are needed to express the trait. Represented with a lowercase letter (e.g., “a”).
Q4: What does it mean to be homozygous or heterozygous?
Homozygous: Having two identical alleles for a gene (e.g., “AA” or “aa”).
Heterozygous: Having two different alleles for a gene (e.g., “Aa”).
Q5: What is a monohybrid cross?
a cross between two individuals that differ in only one trait, where each parent is homozygous for that trait
Q6: What is a dihybrid cross?
a mating experiment between two organisms that are identically hybrid for two traits
Q7: What is the difference between phenotype and genotype?
Phenotype: The physical appearance or expression of a trait (e.g., purple flowers).
Genotype: The genetic makeup of an organism (e.g., “AA” or “Aa”).
Q8: What are the P, F1, and F2 generations?
P generation: The parent generation.
F1 generation: The first filial (offspring) generation.
F2 generation: The second filial generation, produced by crossing individuals from the F1 generation.
Q9: What is a testcross?
A testcross is used to determine the genotype of an individual with a dominant phenotype by crossing it with a homozygous recessive individual.
Q10: What is the Law of Segregation?
The Law of Segregation states that during gamete formation, the two alleles for each gene separate, so each gamete receives only one allele.
Q11: What is the Law of Independent Assortment?
A11: The Law of Independent Assortment states that genes located on different chromosomes are inherited independently of one another during meiosis.
