Question 1

Which of the following best describes Mendel’s Law of Segregation?

Accepted Answer

Alleles for a trait separate during gamete formation, and each gamete receives only one allele.

Question 2

A pea plant with genotype $$Pp ($$where $$P is $$purple and $$p is $$white) is self-crossed. What is the expected phenotypic ratio in the offspring?

Accepted Answer

$$3:1 (3 $$purple: 1 white)

Question 3

Which of the following is an example of a genotype?

Accepted Answer

Homozygous dominant ($$AA)$$

Question 4

If two heterozygous parents ($$Aa) $$for a recessive disease have a child, what is the probability that the child will be affected?

Accepted Answer

$$1/4$$

Question 5

Which process during meiosis explains Mendel’s Law of Independent Assortment?

Accepted Answer

Random orientation of homologous chromosomes during Metaphase I

Question 6

A test cross is performed between a plant with an unknown genotype for a dominant trait and a homozygous recessive plant. If all offspring show the dominant phenotype, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 7

In a dihybrid cross between $$AaBb x$$ $$AaBb$$, what is the probability of obtaining an offspring with genotype $$aabb$$?

Accepted Answer

$$1/16$$

Question 8

Which of the following best explains why a single base mutation in DNA can result in a white-flowered pea plant instead of a purple one?

Accepted Answer

The mutation prevents the synthesis of the enzyme required for pigment production.

Question 9

If a plant with genotype $$AaBb$$ produces gametes, which of the following combinations is possible, assuming independent assortment?

Accepted Answer

$$AB$$, $$Ab$$, $$aB$$, $$ab$$

Question 10

A couple are both carriers ($$Aa) $$for cystic fibrosis, a recessive disorder. What is the probability that their first child will be a boy who is a carrier?

Accepted Answer

$$1/8$$

Question 11

Which of the following statements about alleles is correct?

Accepted Answer

Alleles are different forms of a gene found at the same locus on homologous chromosomes.

Question 12

If two normal parents have a child with sickle cell anemia ($$aa$$), what are the genotypes of the parents?

Accepted Answer

Both $$Aa$$

Question 13

Which of the following best describes a phenotype?

Accepted Answer

The observable characteristics of an organism

Question 14

In a pedigree for an autosomal recessive disorder, which genotype expresses the disorder?

Accepted Answer

$$bb$$

Question 15

Which of the following events during meiosis is responsible for the separation of alleles for a single trait?

Accepted Answer

Anaphase I

Question 16

A plant with genotype $$PP is $$crossed with a plant with genotype $$pp. $$What will be the genotype and phenotype of the F1 generation?

Accepted Answer

All $$Pp$$, all purple

Question 17

If two heterozygous parents ($$Aa) $$have two children, what is the probability that both children will be carriers ($$Aa) $$for a recessive disorder?

Accepted Answer

$$1/16$$

Question 18

Which of the following is NOT a requirement for Mendel’s Law of Independent Assortment to apply?

Accepted Answer

Genes must be linked closely on the same chromosome.

Question 19

A plant with genotype $$Pp is $$crossed with a plant with genotype $$pp. $$What percentage of the offspring will have purple flowers?

Accepted Answer

$$50\%$$

Question 20

Which of the following best explains why Mendel’s experiments with pea plants were so successful in revealing the basic principles of inheritance?

Accepted Answer

He used traits that were controlled by single genes with clear dominant and recessive alleles.

Mendelian Genetics: Principles, Laws, and Applications

Guida di studio - Domande di pratica

Study guide - Flashcard