Final Exam Genetics

1. Which term describes genes that encode essential cellular functions and are expressed continually?

Recessive

Dominant

Constitutive

Variable

Constitutive genes are those that are continually expressed and encode essential cellular functions. Other options do not correctly describe this concept.

Explanation

Constitutive genes are those that are continually expressed and encode essential cellular functions. Other options do not correctly describe this concept.

2. What kind of mutation causes the continuous transcription of one or more structural genes?

Nonsense mutation

Silent mutation

Missense mutation

Constitutive mutation

Constitutive mutations lead to the continuous transcription of genes, resulting in elevated levels of the gene products. Silent mutations do not alter the amino acid sequence, missense mutations change a single amino acid, and nonsense mutations introduce a premature stop codon.

Explanation

Constitutive mutations lead to the continuous transcription of genes, resulting in elevated levels of the gene products. Silent mutations do not alter the amino acid sequence, missense mutations change a single amino acid, and nonsense mutations introduce a premature stop codon.

3. Gene regulation in which the binding of a regulatory protein to DNA stimulates transcription is known as:

Bidirectional gene regulation

Tandem gene regulation

Positive gene regulation (positive control)

Negative gene regulation (negative control)

In positive gene regulation, the binding of a regulatory protein to DNA enhances transcription activity. Negative gene regulation involves the inhibition of transcription by regulatory proteins. Bidirectional gene regulation refers to regulation of two genes in opposite directions. Tandem gene regulation does not refer to a specific type of gene regulation.

Explanation

In positive gene regulation, the binding of a regulatory protein to DNA enhances transcription activity. Negative gene regulation involves the inhibition of transcription by regulatory proteins. Bidirectional gene regulation refers to regulation of two genes in opposite directions. Tandem gene regulation does not refer to a specific type of gene regulation.

4. Gene regulation in which the binding of a regulatory protein to DNA inhibits transcription (the regulatory protein is a repressor).

Negative control

Positive control

Transcriptional activation

Enhancer regulation

In this case, the regulatory protein acts as a repressor by inhibiting transcription, leading to negative control of gene expression.

Explanation

In this case, the regulatory protein acts as a repressor by inhibiting transcription, leading to negative control of gene expression.

5. What is the term for the mechanisms and systems that control the expression of genes?

Genetic engineering

Gene regulation

Gene sequencing

Genetic modification

Gene regulation refers to the various mechanisms that control the expression of genes, including processes like transcription and translation. Genetic modification involves altering the DNA of an organism, gene sequencing is the process of determining the order of nucleotides in a DNA molecule, and genetic engineering involves manipulating genetic material to produce specific traits in an organism.

Explanation

Gene regulation refers to the various mechanisms that control the expression of genes, including processes like transcription and translation. Genetic modification involves altering the DNA of an organism, gene sequencing is the process of determining the order of nucleotides in a DNA molecule, and genetic engineering involves manipulating genetic material to produce specific traits in an organism.

6. Typically consisting of 60 to 90 amino acids that are responsible for binding to DNA -- functional part of the protein.

Domain

Nucleotide

Enzyme

Peptide

A domain is a distinct functional and/or structural region of a protein that can exist independently or in combination with other domains. Domains are responsible for specific biological functions, such as binding to DNA in this case. Enzymes, nucleotides, and peptides are also important components of proteins, but they do not specifically refer to the functional part responsible for binding to DNA.

Explanation

A domain is a distinct functional and/or structural region of a protein that can exist independently or in combination with other domains. Domains are responsible for specific biological functions, such as binding to DNA in this case. Enzymes, nucleotides, and peptides are also important components of proteins, but they do not specifically refer to the functional part responsible for binding to DNA.

7. Within a domain, only a few amino acids actually make contact with the DNA. These amino acids often form _____ bonds with the bases or interact with the sugar-phosphate backbone of the DNA.

Covalent

Van der Waals

Ionic

Hydrogen

Amino acids form hydrogen bonds with DNA bases or interact with the sugar-phosphate backbone due to their specific chemical properties. While ionic, covalent, and van der Waals interactions exist in biological systems, they are not the primary type of bonding involved in the interaction between amino acids and DNA.

Explanation

Amino acids form hydrogen bonds with DNA bases or interact with the sugar-phosphate backbone due to their specific chemical properties. While ionic, covalent, and van der Waals interactions exist in biological systems, they are not the primary type of bonding involved in the interaction between amino acids and DNA.

8. Why is transcription a critical level of gene regulation in both bacterial and eukaryotes?

Because it is the first step in the process of information transfer from DNA to protein. For cellular efficiency, gene expression is often regulated early in the process of protein production.

Because it occurs after translation in the gene expression process.

Because it is not essential for protein synthesis in cells.

Because it only regulates gene expression in bacteria but not in eukaryotes.

9. How do amino acids in DNA-binding proteins interact with DNA?

By forming peptide bonds with the DNA nucleotides.

By forming hydrogen bonds with DNA bases

By covalently bonding to the sugar-phosphate backbone of DNA.

By breaking the phosphodiester bonds in DNA strands.

Amino acids in DNA-binding proteins interact with DNA by forming hydrogen bonds with DNA bases. This interaction allows for specific binding between the protein and the DNA sequence.

Explanation

Amino acids in DNA-binding proteins interact with DNA by forming hydrogen bonds with DNA bases. This interaction allows for specific binding between the protein and the DNA sequence.