Types of Mutations

What are mutations?

Changes in the nucleotide sequence of DNA.

In which cells do mutations occur that are not passed to offspring?

Somatic cells.

What type of cells can mutations occur in that can be passed to offspring?

Gametes (eggs and sperm).

Are most mutations harmful, helpful, or neutral?

Almost all mutations are neutral.

What external factors can cause mutations?

Chemicals and UV radiation.

How are many mutations repaired?

By enzymes.

What are some consequences of somatic mutations?

They can result in skin cancers and leukemia.

What can some mutations do for an organism?

They may improve an organism's survival (beneficial).

What are chromosome mutations?

Mutations that may involve changing the structure of a chromosome or the loss or gain of part of a chromosome.

Name the five types of chromosome mutations.

Deletion, Inversion, Translocation, Nondisjunction, Duplication.

What happens during a deletion mutation?

A piece of a chromosome is lost due to breakage.

What occurs during an inversion mutation?

A chromosome segment breaks off, flips around backwards, and reattaches.

What is a duplication mutation?

Occurs when a gene sequence is repeated.

What is translocation in chromosome mutations?

Part of one chromosome is transferred to another non-homologous chromosome.

What is nondisjunction?

Failure of chromosomes to separate during meiosis, causing gametes to have too many or too few chromosomes.

What are gene mutations?

Changes in the nucleotide sequence of a gene, which may involve a single nucleotide.

What can cause gene mutations?

Copying errors, chemicals, viruses, etc.

Name the types of gene mutations.

Point Mutations, Substitutions, Insertions, Deletions, Frameshift.

What is a point mutation?

Change of a single nucleotide, including deletion, insertion, or substitution of one nucleotide in a gene.

What is an example of a point mutation?

Sickle Cell disease, which results from one nucleotide substitution in the hemoglobin gene.

What is a frameshift mutation?

Inserting or deleting one or more nucleotides, changing the 'reading frame' and causing proteins to be built incorrectly.

How does a frameshift mutation affect a sentence?

It changes the meaning, similar to how adding or removing letters can alter a sentence.