Week 3 Flashcards
What are genetics?
Genetics is the study of the genetic make-up of an organism and how this influences the organisms’ physical characteristics and behavior.
What is heredity?
Heredity is the study of how genes and traits are passed down through generations
What are genes?
A gene is a sequence of DNA that codes a specific protein; genes can vary widely in size and in importance; Genes are organized into pairs of long strands called chromosomes.
What are proteins?
Proteins can either be structural (building blocks of the body) or they can be enzymes (control the chemistry of the body)
What do DNA, genes and proteins have in common?
They are all influenced by their environment – both nature and nurture are very important.
Are the actions of a gene fixed?
The action of a single gene may not be fixed from the start; it can be influenced by the acts of other genes and/or the environment.
Genotype
Genetic makeup
Phenotype
Physical characteristics
Locus
an area on the chromosome where the gene is found.
Alleles
alternative forms of a gene (I.e. brown or blue eye probability)
Homozygous
two identical genes at the same locus
Heterozygous
two different genes at the same locus
When it is heterozygous what gene will be expressed?
The dominant gene will always be expressed, while the recessive gene will not, yet the allele will be carried.
What is polygenetic?
When multiple genes combine to produce a characteristic.
What are behavior genetics?
The study of genetic variation as it relates to behavior
What is the heritability coefficient and what does the 0-1 range mean?
It is a concept used to measure how much a given trait depends on genetic factors versus environmental factors. The 0-1 range is that 1 the trait is only influenced by genetics and 0 there is no impact of genetics in that trait.
What are popular techniques for studying genetic information?
Adoption studies and twin studies: both identical (monozygotic) and fraternal (dizygotic).
Why are twin studies useful?
Twin studies are useful as they show the difference between nature and nurture as they share similar environments but share the same genetics (monozygotic) or have different genetics (dizygotic).
What is phenotypic plasticity?
Changes in response to the environment.
How does DNA fit into a nucleus?
To fit DNA into a nucleus, sections of it are wrapped tightly around globular proteins called histones, which are then wrapped together to form a nucleosome.
What is the entire DNA/ protein complex called?
Chromatin
What is epigenetics and how do they work?
Epigenetics are when the environmental effect alters the expression of a gene, and they work because genes can turn off and on.
What is DNA methylation, why is it significant and what is the effect of methylation and unmethylation on epigenetics?
Where a methyl group is added to cytosine bases. It is significant because it is how genes are turned off and on in epigenetics where methylation means gene is off and unmethylation means gene is on.
What are examples of epigenetics?
Rat pups are born with a highly methylated and inactive glucocorticoid receptor (GR gene) but when rat mothers lick their pups a lot it induces a demethylation of the GR gene, making it more active. Therefore, pups will be more relaxed in response to stress: GR gene demethylation which increases glucocorticoid receptors.
Decreased DNA methylation increased historic acetylation and increased receptors in the brain.
Conversely, Low licking mothers= higher stress response
Means increased DNA methylation
Decreased historic acetylation
Decreased receptors in the brain
