Lecture 8

Question 1

What are chromosomes?

Answer 1

Matched pairs (one from mother, one from father).

Question 2

How many copies of each gene does a cell contain?

Answer 2

2

Question 3

What is an allele?

Answer 3

Matching copies of a gene-not necessarily identical! Leads to increased variability.

Question 4

What is wildtype?

Answer 4

The most common (normal) phenotype or genotype. Used as a control in a lab-anything that differs is a mutant.

Question 5

What is phenotype?

Answer 5

The appearance of an organism that results from the interaction of genes with one another and the environment

Question 6

What is genotype?

Answer 6

The full set of genes that a given organism possesses

Question 7

What is a mutation?

Answer 7

Any alteration of an allele that yields a different version of that allele

Question 8

What is the dominant allele?

Answer 8

The one that is routinely expressed (Huntingtons Disease)

Question 9

What is the recessive allele?

Answer 9

The one that is routinely unexpressed (Tay-Sach’s disease)

Question 10

What is huntington’s disease?

Answer 10

Hereditary disease (progressive neurodegenerative disorder) characterized by chorea (ceaseless, involuntary jerky movements) and progressive dementia, ending in death. Symptoms typically start around 35+ years.

Question 11

Why does Huntington’s happen?

Answer 11

Defect in Huntingtin gene, resulting in increased number of CAG repeats on chromosome 4. Results in brain death in the Basal Ganglia and cortex.

Question 12

What is CRISPR?

Answer 12

“Clustered regulalry interspaced short palindromic repeats,” form of acquired immunity. Uses CAS9 to snip DNA.

Question 13

What can CRISPR do?

Answer 13

Creates “knockout animals”- selective removal of a given gene.
Also potentially a cure for genetic disorders.

Question 14

What are some issues with CRISPR?

Answer 14

It’s not actually as specific as we’d like, could lead to eugenics.

Question 15

What are eugenics?

Answer 15

Science of improving the human population by controlled breeding to increase the occurrence of desirable heritable characteristics.

Question 16

What is brain derived neurotrophic factor?

Answer 16

A protein that is important for the health of neurons-neurotrophic factors are responsible for the growth, survival, and maintenance of neurons. Shows that the wild type can still have mutations.

Question 17

What are the different versions of the BDNF allele?

Answer 17

Val Allele-most common
Met Allele- Produces a slightly less effective form of BDNF protein- approximately 1/3 of people inherit a copy of the met allele.

Question 18

What does the met allele affect?

Answer 18

Episodic memory

Question 19

What are epigenetics?

Answer 19

Examines the differences in gene expression related to environment and experience-do not alter a gene, but rather allow or prevent expression.

Question 20

What are some ways of altering genome expression?

Answer 20

1) Histone 2) DNA 3) mRNA

Question 21

What is histone modification?

Answer 21

When a methyl group blocks the histone from opening to prevent transcription

Question 22

What is DNA modification?

Answer 22

Methyl group binds to CG base pairs to block transcriptions

Question 23

What is mRNA modification?

Answer 23

ncRNA binds to mRNA to block translation

Question 24

In what types of people is methylation higher?

Answer 24

People who have committed suicide (higher in the hippocampus)

Question 25

What happens with methylation in children who have experienced abuse?

Answer 25

Methylation happens on the glucocorticoid receptor-results in stress, PTSD, affects development, metabolism, immune response, depression.

Question 26

What is genetic engineering?

Answer 26

The removal, addition, or modification of genes.

Question 27

What are the transgenic techniques?

Answer 27

Transgenic animals-addition of gene

Knockout animals-removal of gene