46. Gene (point) mutations - definition, kinds, mechanism, “molecular diseases”.

Question 1

Point mutation - only one nucleotide pair has a mutation that causes change in genetic code

Answer 1

Point mutation - only one nucleotide pair has a mutation that causes change in genetic code

Question 2

Missense - substitution of a nucleotide resulting in a different amino acid —> different or non-functional protein

Nonsense - substitution of nucleotide resulting in a stop codon —> non-functional protein
Silent mutation - substitution of a nucleotide (usually 3rd) that codes, results in the same amino acid or previous

Answer 2

Missense - substitution of a nucleotide resulting in a different amino acid —> different or non-functional protein

Nonsense - substitution of nucleotide resulting in a stop codon —> non-functional protein
Silent mutation - substitution of a nucleotide (usually 3rd) that codes, results in the same amino acid or previous

Question 3

Frameshift - deletion / insertion of a nucleotide, change in reading frame - the earlier this happens, the more the protein is affected

Block mutation - changes to segments of chromosome (changes regulation of gene expression)

Duplication - part is copied and put behind copied segment Inversion - part is removed and entered in reverse 180* Deletion - portion of chromosome is lost

Answer 3

Frameshift - deletion / insertion of a nucleotide, change in reading frame - the earlier this happens, the more the protein is affected

Block mutation - changes to segments of chromosome (changes regulation of gene expression)

Duplication - part is copied and put behind copied segment Inversion - part is removed and entered in reverse 180* Deletion - portion of chromosome is lost

Question 4

Insertion - part of chromosome is removed and added to different one

Translocation - segments of 2 chromosomes are exchanged (exchange of 2 chromosome segments)

Molecular disease - disease in which there is an abnormality or deficiency of a particular molecule e.g. sickle cell anaemia

Answer 4

Insertion - part of chromosome is removed and added to different one

Translocation - segments of 2 chromosomes are exchanged (exchange of 2 chromosome segments)

Molecular disease - disease in which there is an abnormality or deficiency of a particular molecule e.g. sickle cell anaemia

Question 5

Missense mutation - a base substitution may lead to an amino acid substitution —> non-functional protein

Nonsense mutation - a mutation that produces a stop codon —> non-functional protein

Answer 5

Missense mutation - a base substitution may lead to an amino acid substitution —> non-functional protein

Nonsense mutation - a mutation that produces a stop codon —> non-functional protein

Question 6

Diseases:

Cystic fibrosis

Cancer

Neurofibromatosis

Sickle cell anaemia

Tay-Sachs disease

Colour blindness

Answer 6

Diseases:

Cystic fibrosis

Cancer

Neurofibromatosis

Sickle cell anaemia

Tay-Sachs disease

Colour blindness