Population Genomics: DNA and Mutations

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Questions and Answers

What is the primary role of nucleotides in genetic coding?

They store energy for cellular processes.

They facilitate cell division.

They express phenotypic traits.

They encode for amino acids in proteins. (correct)

Which type of mutation results in a change of the encoded amino acid to a termination amino acid?

Frameshift mutation

Missense mutation

Nonsense mutation (correct)

Silent mutation

What distinction exists between synonymous and non-synonymous mutations?

Synonymous mutations always result in a STOP codon.

Synonymous mutations do not affect the encoded amino acid. (correct)

Non-synonymous mutations involve insertion or deletion.

Non-synonymous mutations do not change the protein.

What is meant by the term 'degenerate' in the context of the genetic code?

Multiple codons can encode for the same amino acid. Signup and view all the answers

Which of the following correctly describes a frameshift mutation?

It alters the reading frame of the codons. Signup and view all the answers

What do you call the mutation that involves swapping one nucleotide for another?

Point mutation Signup and view all the answers

What consequence can an in-frame insertion or deletion have on a protein?

It can lead to the addition or loss of specific amino acids. Signup and view all the answers

Which of the following nucleotides will pair with Thymine (T) in DNA?

Adenine (A) Signup and view all the answers

What occurs during a transversion mutation?

A pyrimidine is substituted for a purine. Signup and view all the answers

What describes a consequence of a silent mutation?

There is no change to the encoded amino acid. Signup and view all the answers

Which of the following best defines a point mutation?

A change affecting only a single nucleotide in the DNA sequence. Signup and view all the answers

What is the relationship between the number of codons and amino acids in the genetic code?

Codons outnumber amino acids due to redundancy. Signup and view all the answers

What defines a frameshift mutation?

An insertion or deletion that alters the reading frame. Signup and view all the answers

Which type of nitrogenous base substitution is characterized by replacing a purine with another purine?

Transition Signup and view all the answers

What is a major consequence of nucleotide insertions in a gene?

They can lead to an in-frame change in the protein sequence. Signup and view all the answers

Which of these best describes a nonsense mutation?

It creates a stop codon, terminating protein synthesis prematurely. Signup and view all the answers

What type of genetic variant involves the addition of one or more nucleotides to the DNA sequence?

Insertion mutation Signup and view all the answers

Which of the following describes a transition mutation?

Swapping a purine for another purine Signup and view all the answers

What is a consequence of a non-synonymous mutation?

Change in the encoded amino acid Signup and view all the answers

Which of the following correctly characterizes a silent mutation?

It has no effect on the encoded amino acid Signup and view all the answers

What is the primary characteristic of a frameshift mutation?

It results from nucleotide insertions or deletions Signup and view all the answers

Which statement best describes the genetic code's redundancy?

It allows a single amino acid to be encoded by multiple codons Signup and view all the answers

Which of the following types of mutations involves replacing one base with another of a different category?

Transversion mutation Signup and view all the answers

What role do codons play in the genetic code?

They encode specific amino acids Signup and view all the answers

Study Notes

DNA Nucleotides

DNA is made up of four nucleotides: Adenine (A), Guanine (G), Thymine (T), and Cytosine (C).
Adenine pairs with Thymine, and Guanine pairs with Cytosine.
Adenine and Guanine are purines.
Thymine and Cytosine are pyrimidines.

Genetic Code

Three nucleotides (a codon) specify an amino acid.
The genetic code table shows the codons and corresponding amino acids.
Example: UUU codes for Phenylalanine.
The genetic code is redundant, meaning some amino acids can be coded for by more than one codon.
This redundancy helps to reduce the impact of mutations.

Types of Genetic Variants

DNA Mutations: Changes in the DNA sequence.
Point Mutations: Changes in a single nucleotide.
- Substitution: Replacing one nucleotide with another.
  - Transition: Swapping a purine for a purine or a pyrimidine for a pyrimidine.
  - Transversion: Swapping a purine for a pyrimidine or vice versa.
- Consequences:
  - Synonymous/Silent: No change in the encoded amino acid.
  - Missense: Change in the encoded amino acid.
  - Nonsense: Change to a stop codon, truncating the protein.
Insertion/Deletion (Indels): Additions or removals of one or more nucleotides.
- In-Frame: Insertions/deletions in multiples of three, maintaining the reading frame.
- Frame-Shift: Insertions/deletions not in multiples of three, altering the reading frame which changes the entire downstream amino acid sequence.

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Description

Test your knowledge on DNA nucleotides, the genetic code, and types of genetic variants. This quiz covers essential concepts such as nucleotide pairing, codon function, and the implications of DNA mutations. Perfect for students interested in genetics and molecular biology.