Neurogenetics

Question 1

What are single nucleotide polymorphisms (SNPs)?

Answer 1

Natural variations in DNA sequence

Question 2

What is the genetic basis of variation?

Answer 2

The unique combination of SNPs we inherit from our parents

Question 3

What does mitosis produce?

Answer 3

Somatic cells

Question 4

What does meiosis produce?

Answer 4

Gametes

Question 5

What process in meiosis generates genetic diversity?

Answer 5

Crossing over of sister chromatids

Question 6

What do transcription factors do?

Answer 6

Turn on genes

Question 7

Describe the process of transcription

Answer 7

Transcription factor binds to DNA, reads sequence and produces mRNA (which is a copy of the DNA sequence)

Question 8

Describe the process of translation

Answer 8

Ribosome moves along mRNA reading each triplet codon, uses tRNA to assemble amino acid chain to make a protein

Question 9

What type of inheritance does Huntington’s Chorea have?

Answer 9

Autosomal dominant

Question 10

What type of inheritance does phenylketonuria have?

Answer 10

Autosomal recessive

Question 11

What is Huntington’s caused by?

Answer 11

Excessive CAG repeats on chromosome 4 leading to degeneration of striatum; progressive degeneration of movement, temperament and cognition

Question 12

What is phenylketonuria caused by?

Answer 12

Mutation in phenylalanine hydroxylase gene leading to inability to digest phenylalanine; potential toxic build-up in brain

Question 13

What is monosomy?

Answer 13

Single copy of a chromosome (one absent copy)

Question 14

What is trisomy?

Answer 14

Three copies of a chromosome (one excessive copy)

Question 15

What is Down’s syndrome?

Answer 15

Trisomy in chromosome 21; smaller brain size, intellectual difficulties, higher risk of early-onset Alzheimer’s