Viruses and Mutations: Impact on Genetic Material

Viruses

Simple structures consisting of a nucleic acid core, containing their genetic code, a protein capsid, and sometimes an outer envelope that helps the virus attach to or enter host cells.

Abiotic factors

Factors that do not contain all of the characteristics of life, such as viruses, which don't maintain homeostasis or grow.

Lysogenic cycle

A cycle where the virus remains dormant, with its DNA embedded into the host cell and replicated within it, permanently changing the genome of the host cell.

Mutations

Changes in genetic material that can be caused by mutagens such as UV radiation, pollution, chemicals, and viruses.

Inherited mutations

Mutations that must occur in gametes during cell division to be passed down to offspring.

Point mutations

Random mutations that occur in the base of DNA during replication.

Frameshift mutation

A mutation that causes a shift in the reading frame, which is worse than substitution.

Substitution mutation

A single change in the ATCG base sequence of DNA.

Deletion mutation

A segment of DNA is lost or removed.

Insertion mutation

One or more extra nucleotides are added to the DNA sequence, disturbing the normal reading frame.

Silent mutation

A change in the DNA base that does not result in a change in the amino acid sequence.

Missense mutation

A change in a single nucleotide that results in a different amino acid sequence.

Nonsense mutation

Codons that normally code for an amino acid sequence change to a stop codon.

Harmful mutations

Mutations that can negatively affect an organism depending on its habitat.

Practice Question 1

Which type of mutation is most likely to be harmful? A) Silent mutation B) Frameshift mutation C) Point mutation D) Neutral mutation

Practice Question 2

What is the main function of the protein coat (capsid) of a virus? A) To produce energy for viral replication B) To store genetic material C) To protect the viral genetic material and help the virus attach to host cells D) To carry out photosynthesis for the virus

Practice Question 3

Which statement accurately describes the lysogenic cycle of a bacteriophage? A) The bacteriophage immediately replicates within the host cell, leading to cell lysis. B) The bacteriophage's DNA integrates into the host cell's genome and replicates along with it without causing immediate harm. C) The bacteriophage remains outside the host cell, producing toxins that damage the host. D) The bacteriophage's RNA is directly translated into proteins, bypassing DNA integration.

Answer to Practice Question 1

B) Frameshift mutation

Answer to Practice Question 2

C) To protect the viral genetic material and help the virus attach to host cells

Answer to Practice Question 3

B) The bacteriophage's DNA integrates into the host cell's genome and replicates along with it without causing immediate harm.