Lecture 1 - Behavioural genetics

Question 1

What are the steps in natural selection?

Answer 1

1. Variation between individuals
2. Variation is heritable
3. Individuals less well adapted are less likely to survive - (Survival of the fittest)

Question 2

What did Cosmides and Tooby (1992) propose?

Answer 2

Likened the mind to a Swiss army knife - crammed with specific tools for specific tasks

Question 3

Who discovered the double helix structure of DNA?

Answer 3

Crick and Watson

Question 4

Why is it important that DNA has a double helix structure?

Answer 4

Enables the replication of the DNA strands

Question 5

What process allows DNA to become mRNA?

Answer 5

Transcription

Question 6

Not all DNA is transcribed. The parts that are are called…

Answer 6

Exons

Question 7

Who discovered the laws of genetic inheritance?

Answer 7

Gregor Mendel, 1850-1860

Question 8

What does Genotype mean?

Answer 8

Refers to the set of genes an organism possesses

Question 9

What does Phenotype mean?

Answer 9

Refers to the appearance of an organism that results from the interaction between the genes and the environment

Question 10

What does Homozygous mean?

Answer 10

2 Identical alleles

Question 11

What does heterozygous mean?

Answer 11

2 different alleles

Question 12

What does polymorphism mean?

Answer 12

Common different forms of a gene

Question 13

What does the process of Knockout Technology involve?

Answer 13

Gene removed or inactivated so not expressed

- Useful to determine function of different genes

Question 14

What are the symptoms of Huntingdon’s disease?

Answer 14

• chorea
• cognitive deficits
• psychiatric deficits

Question 15

What is Huntington’s disease?

Answer 15

The degeneration of neutrons in the caudate nucleus and putamen

Question 16

What are the symptoms of Tay-Sachs disease?

Answer 16

• Seizures
• blindness
• degeneration or motor and mental abilities
• death after a few years

Question 17

What is Tay-Sachs disease?

Answer 17

Caused by a dysfunctional protein that acts as an enzyme, known as HexA.

Leads to a failure in the breaking down of lipids in the brain

Question 18

What is heritability?

Answer 18

An estimate of the proportion of variability that occurred in a particular trait as a result of genetic variation

Question 19

What is epigenetics?

Answer 19

The idea that the external environment can modify gene expression by influencing the DNA function

Question 20

Tryon’s (1934) study

Answer 20

Trained rats on a maze
- Interbred rates that made the fewest mistakes, and those that made the most mistakes

= Bright rats, easily solved maze
=Dull rats - found it harder

Eventually the overlap between scores was removed as the bright rats became Bettie and the dull rats worse
–> shows that some elements of intelligence are likely to be genetic (polygenic)

Question 21

How did Searle’s (1949) findings contradict Tryon’s?

Answer 21

found that this selective breeding (rats) affected up to 30 traits bedsides intelligence

• bright rats tended to be less emotional

Question 22

What did Cooper and Zubeck (1958) find in relation to Tyron’s study?

Answer 22

• Environment in which the rats were raised had an influence on their level of learning
• in a restricted environment, both sets of rats made a large number of errors
• in an enriched environment, both sets of rats made considerably less mistakes
• Interaction of environment and genes

Question 23

Plomin and DeFries (1998)

Answer 23

Compared twins on a range of cognitive tasks

• On all tasks, the twins ability was more similar if they were monozygotic compared with those that were dizygotic