Mutations Flashcards
(22 cards)
How are mutations caused?
Caused by a random change in an organism’s DNA. One or more of the nitrogenous basis have been changed.
How do mutation occur during the process of making copies of your DNA?
If an incorrect nitrogen base is copied, and the make is not detected by your cell, it becomes a mutation.
External causes of mutation
- exposure to high energy rays ( radioactive chemicals )
- exposure to chemicals
( drugs, alcohol)
Types of gene mutations
Point mutation, frameshift mutation
Point mutation
Change in one or a few nucleotides
Substitution, insertion, deletion
Substitution
Adding a letter
Insertion
Adding a sequence
Deletion
Deleting a sequence
Frameshift mutation
Shift the reading frame so the genetic code will not make sense
Insertion, deletion
Somatic mutation
- Affect any cell besides sex cells
-does not get passed onto offspring
Germline mutation
Affects a sperm or egg and every cell in your body will have this mutation and it may get passed on to offspring.
Positive mutation
Some mutations provide an advantage, which improve the chances of survival of an organism.
Example of positive mutation
A longer neck for giraffes so that they can eat from tall trees.
Neutral mutation
Does not affect the chance of survival of an organism
Example of a neutral mutation
Freckles, attached earlobes
Negative mutation
Hurt the chance of survival of an organism
Example of negative mutation
Cause of cancer, disease like cystic fibrosis
A mutation may be positive, neutral, negative depending on
The environment
How do mutations affect life?
Mutations, genetic diversity, natural selection, evolution
Genetic diversity
Different types of alleles in the population of an organism
Natural selection
Process where favourite traits are more likely to survive and be passed on to offspring “survival of the fittest”
Evolution
Theory behind how a species change is gradually over thousands of years. Takes place because of natural selection.
