Question 1

Which of the following best describes the principle of segregation as discovered by Mendel in his monohybrid crosses?

Accepted Answer

Each individual has two alleles for each gene, and these alleles separate during gamete formation so that each gamete receives only one allele.

Question 2

A true-breeding pea plant with purple flowers (PP) is crossed with a true-breeding plant with white flowers (pp). What is the expected genotype and phenotype ratio in the F1 generation?

Accepted Answer

Genotype: 100% Pp; Phenotype: 100% purple

Question 3

In a dihybrid cross between two heterozygous pea plants (PpRr x PpRr), what is the expected phenotypic ratio among the F2 offspring for the traits of flower color (purple dominant to white) and seed shape (round dominant to wrinkled)?

Accepted Answer

$$9:3:3:1$$

Question 4

Which of the following statements about Mendel’s use of model organisms is correct?

Accepted Answer

He chose pea plants because their traits are easily recognizable and they produce many offspring in a short time.

Question 5

A heterozygous tongue-roller (Rr) male mates with a non-tongue-roller (rr) female. What percentage of their children are expected to be tongue-rollers?

Accepted Answer

$$50\%$$

Question 6

Which of the following best explains the principle of independent assortment?

Accepted Answer

Alleles for different genes segregate independently of one another during gamete formation.

Question 7

If a plant with genotype PpRr produces gametes, which of the following represents all possible gamete genotypes it can produce?

Accepted Answer

PR, Pr, pR, pr

Question 8

A cross between two heterozygous round-seeded pea plants (Rr x Rr) results in what genotypic ratio among the offspring?

Accepted Answer

$$1\ RR : 2\ Rr : 1\ rr$$

Question 9

Which of the following is a real-world example of a model organism used in genetics research, as discussed in the study materials?

Accepted Answer

Fruit flies (Drosophila melanogaster)

Question 10

Which of the following best describes a pure line (true-breeding line) in Mendel’s experiments?

Accepted Answer

A line that, when self-fertilized, produces offspring identical to the parent for a given trait.

Question 11

If a plant with genotype Rr is self-fertilized, what is the probability that an offspring will be homozygous recessive?

Accepted Answer

$$\frac{1}{4}$$

Question 12

Which of the following is NOT a reason Mendel’s choice of pea plants was advantageous for his experiments?

Accepted Answer

Pea plants have traits that are difficult to distinguish.

Question 13

Which of the following best describes the difference between genotype and phenotype?

Accepted Answer

Genotype refers to the genetic makeup, while phenotype refers to the observable characteristics.

Question 14

A plant with genotype PpRr is crossed with a plant with genotype pprr. What proportion of the offspring are expected to have purple flowers and wrinkled seeds? (Assume purple is dominant to white, round is dominant to wrinkled.)

Accepted Answer

$$\frac{1}{4}$$

Question 15

Which of the following historical hypotheses about inheritance was disproven by Mendel’s experiments?

Accepted Answer

The blending inheritance hypothesis

Question 16

During meiosis, how does the behavior of chromosomes explain Mendel’s principle of independent assortment?

Accepted Answer

Chromosomes align randomly at the metaphase plate, so alleles of different genes are distributed independently into gametes.

Question 17

In a human family, both parents are heterozygous for a recessive genetic disorder (Aa). What is the probability that their child will inherit the disorder?

Accepted Answer

$$\frac{1}{4}$$

Question 18

Which of the following best explains why Mendel’s principles apply to humans as well as pea plants?

Accepted Answer

The basic mechanisms of inheritance are conserved across many species.

Question 19

A geneticist is studying a trait controlled by a single gene with two alleles. If the dominant allele is represented by A and the recessive by a, which cross would produce both homozygous and heterozygous offspring in a 1:1 ratio?

Accepted Answer

Aa x aa

Question 20

Which of the following scenarios best illustrates the application of Mendel’s principles to a real-world medical case?

Accepted Answer

A patient inherits a dominant allele for a disease from one parent and a recessive allele from the other, resulting in the disease phenotype.

Mendelian Genetics and Patterns of Inheritance: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard