Mutations

Question 1

what is a genetic mutation

Answer 1

a random, rare alteration in genetic matieral

Question 2

causes of mutations?

Answer 2

• can occur naturally (during DNA replication)

- exposure to chemicals/radiation

Question 3

types of mutations

Answer 3

• deletion
• insertion
• substituion

Question 4

what is a deletion mutation

Answer 4

one in which one or more nucleotide bases are lost or deleted

Question 5

What is an insertion mutation

Answer 5

mutations in which extra base pairs are inserted into DNA

Question 6

what are the consequences of deletion/insertion mutations

Answer 6

• since the genetic code is read in codons, it changes the frameshift (the way the message is read)

Question 7

what is a substitution mutation

Answer 7

exchanges one base for another

Question 8

consequences of substitution mutations

Answer 8

CHANGE IN CODONS:

• encodes the same amino acid (causes no change in the protein produced, this is called a silent mutation)
• corresponds to a stop codon&raquo_space;> incomplete protein
• encodes a different amino acid + change in protein produced

Question 9

what is sickle cell anemia

Answer 9

a disease caused by a single base substitution of the gene that makes hemoglobin (protein that carries oxygen in RBCs)

-changes glutamic acids to valine

Question 10

consequences of sickle cell anemia

Answer 10

• causes the hemoglobin to become deactive, shaped like a sickle and stiff, and unable to carry oxygen around the blood +get stuck in blood vessels
• makes hemoglobin clump together +changes shape

Question 11

positive effects of sickle cell anemia

Answer 11

-carriers are resistant to malaria, because parasite dies inside cells with the sickle gene

Question 12

what is cystic fibrosis

Answer 12

• disease resulted from a deletion of three DNA nucleotides
• deletes the amino acid phenylaline
• genetic disorder (recessive trait)

Question 13

what are the consequences of cystic fibrosis

Answer 13

• affects the CFTR protein, cannot fold properly (DEACTIVATES IT)
• unable to carry chloride ions
• excess salt in the cells absorb water and make the lung and pancreas surfaces sticky
• catches bacteria and causes infections

Question 14

what does the CFTR protein do

Answer 14

• channel protein responsible for the movement of the chloride ion in and out of the cell
• maintains balance of salt and water on lung and pancreas surface