Q: Which of the following is a correct representation of the central dogma of molecular biology?

$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best describes Mendel's Principle of Independent Assortment?

Accepted Answer

Alleles for different traits assort independently of one another during gamete formation.

Question 2

A plant with genotype RrYy is crossed with another plant of the same genotype. According to the dihybrid cross, what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 3

Which of the following scenarios best illustrates incomplete dominance?

Accepted Answer

A cross between red and white flowers produces pink offspring.

Question 4

In a test cross, a pea plant with an unknown genotype for seed color is crossed with a plant that is homozygous recessive for seed color. If all offspring are yellow, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant

Question 5

Which of the following is an example of a pleiotropic gene?

Accepted Answer

A single gene that affects multiple traits, such as the Marfan syndrome gene affecting connective tissue, heart, and eyes.

Question 6

Which statement about X-linked recessive inheritance is correct?

Accepted Answer

Affected males pass the trait to all their daughters and to none of their sons.

Question 7

Which of the following best explains why telomeres are important in eukaryotic chromosome replication?

Accepted Answer

They prevent the loss of genetic information at the ends of chromosomes during replication.

Question 8

During DNA replication, which enzyme synthesizes short RNA primers needed to start the process?

Accepted Answer

Primase

Question 9

Which of the following is a correct representation of the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 10

A mutation changes a codon from UAU (tyrosine) to UAA. What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 11

Which of the following best describes the function of DNA ligase during replication?

Accepted Answer

It joins Okazaki fragments together on the lagging strand.

Question 12

If a child has a genetic disorder caused by a dominant allele, but neither parent shows symptoms, what is the most likely explanation?

Accepted Answer

The disorder is caused by a new mutation in the child.

Question 13

Which of the following is true about codominance?

Accepted Answer

Both alleles are expressed equally in the phenotype.

Question 14

A woman who is heterozygous for an X-linked recessive trait and a man who does not have the trait have a son. What is the probability that the son will have the trait?

Accepted Answer

$$0.5$$

Question 15

Which process is responsible for the physical separation of alleles during meiosis?

Accepted Answer

Segregation

Question 16

Which of the following is a valid reason why fruit flies (Drosophila) are a good model organism for genetic studies?

Accepted Answer

They have easily observable traits and produce many offspring.

Question 17

Which of the following best describes a frameshift mutation?

Accepted Answer

A mutation that adds or deletes a nucleotide, altering the reading frame.

Question 18

Which enzyme is responsible for unwinding the DNA double helix during replication?

Accepted Answer

Helicase

Question 19

A genetic map is constructed using recombination frequencies. If two genes have a recombination frequency of $$20\%$$, how many map units apart are they?

Accepted Answer

$$20$$ map units

Question 20

Which of the following is an exception to the central dogma?

Accepted Answer

Some viruses use reverse transcriptase to turn RNA into DNA.

Genetics and Molecular Biology: Mendel, DNA, and Gene Expression

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