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Flashcards in Chapter 4.2 Deck (15):

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?

1. Determine which gene is mutated
2. Use an inactive virus to carry the healthy gene into the cell
3. The cell starts copying the healthy gene
4. 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.