Q1: In pea plants, purple flowers (P) are dominant to white (p). A homozygous dominant plant is crossed with a white-flowered plant. What percentage of the F1 offspring will be purple?
Answer: D (100%) Explanation: PP x pp = all Pp heterozygotes. Since P is dominant, all show purple.
Q2: In a test cross, an individual with a dominant phenotype (but unknown genotype) is crossed with a:
Answer: C (Homozygous recessive) Explanation: Crossing with a recessive (e.g., pp) reveals the unknown's genotype. If any offspring show the recessive trait, the unknown was heterozygous.
Q3: A man with type AB blood and a woman with type O blood have a child. What is the probability the child has type B blood?
Answer: C (50%) Explanation: AB genotype = I^A I^B. O genotype = ii. Possible offspring: I^A i (Type A) or I^B i (Type B). 50/50.
Q4: X-linked recessive disorders (like hemophilia) are more common in males because:
Answer: B Explanation: Males are hemizygous for X genes. They lack a second X to mask a recessive mutation.
Q5: What is the expected phenotypic ratio from a dihybrid cross (RrYy x RrYy) assuming independent assortment?
Answer: C (9:3:3:1) Explanation: 9 round yellow, 3 round green, 3 wrinkled yellow, 1 wrinkled green.
The answers provided here are accurate based on the course content as of its most recent release. However, Coursera updates questions periodically. Furthermore, the final proctored exam (if your course includes a certificate track) will shuffle questions and numbers (e.g., changing a population size from 100 to 500).
Do not simply Ctrl+F these answers during the quiz. Instead:
“Introduction to Genetics and Evolution” is consistently ranked as one of the best online biology courses available. Taught by the charismatic Professor Mohamed Noor at Duke University, this course bridges the gap between molecular biology (DNA, genes, mutations) and population genetics (natural selection, drift, evolution).
However, the quizzes are notoriously tricky. They test nuance, not just memorization. You might know what a “nucleotide” is, but can you predict the outcome of a cross involving X-linked traits in a species where females are the heterogametic sex?
This guide provides verified answers for all weekly quizzes, plus detailed explanations so you understand the why behind each answer.
Q1: In a population of 100 individuals, 36 have blue eyes (recessive, bb). How many are heterozygous (Bb)?
Q2: Which of the following is NOT a condition of Hardy-Weinberg equilibrium?
Q3: Genetic drift has the strongest effect in:
Scenario Question: A population of birds has two colors: brown (dominant) and white (recessive). After a hurricane, only 10 birds remain, and by chance, 8 are brown. How has the gene pool changed?
Q1: The Biological Species Concept defines a species as:
Answer: C Explanation: Ernst Mayr’s definition. Key phrase: “reproductively isolated.”
Q2: Which of the following is a pre-zygotic reproductive barrier?
Answer: C Explanation: Pre-zygotic barriers act before fertilization. Temporal isolation prevents mating. The others are post-zygotic.
Q3: In a phylogenetic tree, the point where a single lineage splits into two is called a:
Answer: A (Node) Explanation: Nodes represent the most recent common ancestor of the descendant lineages.
Q4: A monophyletic group (clade) includes:
Answer: B Explanation: This is the definition of a true clade (a “natural” group in evolution).
Q5: Which type of mutations are most useful for comparing closely related species?
Answer: B Explanation: Closely related species have few differences, so you need a fast-evolving region (like mtDNA) to see variation. Slow-evolving genes (like rRNA) are used for distantly related species.
Some additional resources for learning genetics and evolution include:
Let me know if you'd like more suggestions or have any other questions.
I hope you find these resources helpful in your learning journey.
How one species becomes two, and how we reconstruct evolutionary history.