Genes and Behaviour

Question 1

What do genes produce

Answer 1

protein

Question 2

What are genes

Answer 2

Genes are located on chromosomes (DNA coiled around histones) located in the cell nucleus

Genes are expressed through two linked processes

Question 3

what is gene expression

Answer 3

nscription (RNA transmitted to a protein) + translation

Question 4

Most of the vertebrate genome does not…

Answer 4

code for proteins

Question 5

What animals have more genes than a human

Answer 5

lots including pufferfis

Question 6

what animals have more chromosomes than a human

Answer 6

lots including chicken

Question 7

What % of DNA is shared by human

Answer 7

99.8%

Question 8

What % of human genes are shared w chimpanzees

Answer 8

98%

Question 9

Humans and mice share what % of genes

Answer 9

92%

Question 10

How are eye colours decided

Answer 10

As they are on the same chromosome, they are inherited together.

Question 11

what are diploid organisms

Answer 11

Humans are diploid organisms. This means we have two copies of each chromosome (one from father and one from mother). All vertebrates are diploid.

Question 12

what is homozygous

Answer 12

same alleles. no conflict in gene expression

Question 13

what is heterozygous

Answer 13

different alleles. Brown allele is dominant

Question 14

what is an agouti gene

Answer 14

• involved in coat pattern and shading of mammals
• produces a greyish-brown coat colour
• when upregulated, hair follicle melanocytes switch from making black to yellow pigment

Question 15

what are lethal allels

Answer 15

Lethal alleles lead to death of homozygous recessive offspring.

Homozygous yellow-coated mice die as embryos.
Individuals that have two yellow coat genes will die as embryos.

Question 16

What did Weber et al find

Answer 16

Captive-reared mice placed in sand-filled arena for first time
builds species-typical burrow

F1 offspring of maniculatus × polionotus hybrid
100% escape tunnels

Backcrossed F1 × maniculatus
~50% escape tunnels

A crossbreed of the two mice would build the escape tunnels (100% of the time).
The hybrid was backcrossed against the deer mice. These ¾ deermouse ¼ oldfield, 50% created an escape tunnel.

The simplest explanation of this is that the behaviour is controlled by a gene.

The allele for building an escape tunnel is dominant. In the back cross, half will be homozygous and the other heterozygous which explains why half build the escap tunnel.

single, dominant locus controls building of escape tunnel

Question 17

What does fosB mutation in mice cause

Answer 17

disruption of maternal behaviour: creating a nest, cleaning the pups, retrieving them to the nest, crouching over them for warmth and nursing

Question 18

what effect do mutations have

Answer 18

Most mutations are harmful or neutral in their effects; only rarely are mutations beneficial

Question 19

what percent of alleles are wild type

Answer 19

Alleles at >1% frequency termed wild-type

Question 20

what percent of alleles are mutant

Answer 20

Alleles at <1% frequency termed mutant

Question 21

what is Gene with one wild-type allele

Answer 21

monomorphic

Question 22

what is Gene with >1 wild-type allele

Answer 22

polymorphic

Question 23

what increases mutation rate above spontaneous level

Answer 23

Mutagens and radiation