Chapter 4.2 Flashcards
When does a cell mutation occur?
When there is a change in the specific order of the AGTC bases that make up the DNA
When can mutation happen?
At any time
Identify 3 ways in which a gene can be altered.
Deletion, addition, substitution
What is a positive mutation? Give an example.
A mutation that benefits an organism.
Ex: Some people are resistant to HIV and therefore, AIDS
Ex: Some plants create proteins that protect them against bacterial and fungal infections
What is a negative mutation? Give an example.
A mutation that is harmful to an organism.
Ex: Sickle cell anemia
Ex: Cystic fibrosis
What is a neutral mutation?
A mutation that does not affect the organism.
Most of the time, errors in the base sequence are neutral mutations
Ex: White Kermode Bear
Ex: Different eye colours
What are mutagens? Give examples.
Substances that cause mutations in DNA
Ex: Cigarettes, x-rays, UV radiation, pollutants
How do viruses cause mutations?
Viruses disrupt the instructions stored in the genes and cause genes to be misread or copied incorrectly
What are the steps to gene therapy?
- Determine which gene is mutated
- Use an inactive virus to carry the healthy gene into the cell
- The cell starts copying the healthy gene
- The healthy gene makes healthy proteins
What is a genome?
All the genetic information stored within the chromosomes of a living cell
What are enzymes?
Specialized proteins that speed up the hundreds of chemical reactions that occur within the cell
What are hormones?
Chemical messengers
What is sickle cell anemia?
Something caused by differently shaped hemoglobin molecules
What do abnormally shaped molecules do?
They cannot carry oxygen efficiently.
The block blood flow, causing pain and often organ damage since blood carrying nutrients cannot reach organs.
What is cystic fibrosis and what does it do?
A genetic disease caused by a mutation.
Mucus builds up because the protein that normally functions to transport chloride ions in and out of the cell are not made correctly.
It causes breathing and respiratory system problems.
