Gaokao Exam Biology: Genetics and Evolution 2 — Questions and Answers
Question 1: What is the term for the observable physical characteristics of an organism determined by its genes and environment?
- Genotype
- Phenotype (Correct answer)
- Allele
- Locus
Correct answer: Phenotype
Phenotype refers to the physical expression of traits, such as eye color or height, influenced by both genotype and environment.
Question 2: In Mendel's Law of Independent Assortment, genes on different chromosomes are inherited:
- Together, always linked
- Independently of each other (Correct answer)
- Only from the mother
- In a fixed ratio of 2:1
Correct answer: Independently of each other
Genes located on non-homologous chromosomes segregate independently during meiosis, producing varied combinations in offspring.
Question 3: Which process produces gametes (sperm and egg cells) with half the normal chromosome number?
- Mitosis
- Binary fission
- Meiosis (Correct answer)
- Budding
Correct answer: Meiosis
Meiosis is a two-stage cell division that reduces the chromosome number by half, producing haploid gametes.
Question 4: Fossils, comparative anatomy, and DNA sequence comparisons are all types of evidence for:
- Genetic drift
- Evolutionary relationships (Correct answer)
- Epigenetic inheritance
- Phenotypic plasticity
Correct answer: Evolutionary relationships
These lines of evidence collectively support the theory of evolution by revealing shared ancestry and gradual change over time.
Question 5: What term describes the change in allele frequencies in a population due to random chance, especially in small populations?
- Natural selection
- Gene flow
- Genetic drift (Correct answer)
- Mutation pressure
Correct answer: Genetic drift
Genetic drift is the random fluctuation of allele frequencies due to chance events, most significant in small populations.
Question 6: In a dihybrid cross between two AABB and aabb parents, what is the genotype of all F1 offspring?
- AABB
- aabb
- AaBb (Correct answer)
- AABb
Correct answer: AaBb
Each F1 offspring receives one dominant and one recessive allele for each gene from its parents, giving genotype AaBb.
Gaokao Exam Biology: Genetics and Evolution 2
What is the term for the observable physical characteristics of an organism determined by its genes and environment?