18 Questions
What is the effect of base substitution in a gene mutation?
Has no effect on the encoded protein
Which type of gene mutation involves the addition of nucleotide pairs in a gene?
Base insertion
In gene mutation, what is the effect of missense mutation?
Changes one amino acid to another
Which type of mutation involves the loss of nucleotide pairs in a gene?
Base deletion
What is the term for a mutation that occurs spontaneously without exposure to external factors?
Spontaneous mutation
Which type of mutation involves changes in a single nucleotide pair?
Point mutation
What types of physical agents are mentioned in the text as causes of DNA damage and gene alteration?
UV and gamma rays
How does ethidium bromide cause alterations in DNA?
By creating extra space between DNA bases
What is the effect of base deletion in a gene mutation?
Frameshift mutation
Which mutation results from changes in a single nucleotide pair of a gene?
Point mutation
What is the main characteristic of induced mutations?
They are caused by environmental factors or chemicals
What effect does colchicine have on spindle fiber development?
Prevents homologous chromosome separation
What is the definition of mutation?
A permanent change in the nucleotide sequence of an organism’s DNA
Which type of mutation is characterized by error during DNA replication or recombination?
Point mutation
What is a mutagen?
A chemical or physical agent that interacts with DNA and leads to mutation
Which class of mutation is caused by external factors such as chemical agents?
Induced mutation
What is the outcome of non-disjunction during meiosis?
Production of gametes with abnormal chromosome numbers
Which term refers to a gene that has undergone mutation or an organism carrying a mutated gene?
Mutant
Study Notes
Mutation
- Mutation: a permanent change in the nucleotide sequence of an organism's DNA, important as a source of genetic diversity
- Types of mutation:
- Spontaneous mutation: occurs due to error during DNA replication or recombination
- Induced mutation: caused by mutagens (chemical or physical agents that interact with DNA)
Classification of Mutations
- Two main types of mutations:
- Gene/point mutation: changes in a single nucleotide pair of a gene
- Chromosomal mutation: changes in the number or structure of chromosomes
Gene Mutations
- Definition: changes in a single nucleotide pair of a gene
- Three types of gene mutations:
- Base substitution: one nucleotide pair is replaced with another (e.g. sickle cell anaemia)
- Base insertion: addition of nucleotide pairs in a gene
- Base deletion: loss of nucleotide pairs in a gene (e.g. thalassaemia)
Effects of Base Substitution
- Silent mutation: base substitution has no effect on the encoded protein
- Missense mutation: base substitution changes one amino acid to another
- Nonsense mutation: base substitution leads to the premature termination of protein synthesis
- Frameshift mutation: base insertion or deletion leads to a change in the reading frame of the genetic code
Test your knowledge on gene mutations and their types. Learn about the effects of base substitution, insertion, and deletions on the genetic code.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
