Genetics Flashcards
1
Q
models of nature vs. nurture relationship
A
- all nature/all nurture
- additive model
- interactive model
- transactional model
2
Q
all nature/all nurture model
A
can’t use these models -> every physical psychological and physical trait have some influence from both nature or nurture
3
Q
additive model
A
- each trait is sum of nature vs. Nurture
- this lacks complexity -> it looks at nature vs. Nurture one time and assumes they’re binary (either low or high)
- simple and linear
4
Q
interactive model
A
- nature and nurture exist on a spectrum and interact together to create outcomes
- however, this focuses on one time only
- non-linear (like plants growing at different heights)
5
Q
transactional model
A
- recognizes that nature and nurture interact constantly throughout the lifespan
- nature and nurture influence each other
- spectral
6
Q
genotype
A
- genetic material an individual inherits; constant across the lifespan
- Genetics can change, but the code/genotype itself cannot
7
Q
phenotype
A
- observable characteristics of the genotype, including physical and behavioural characteristics
- Ex. Eye colour, outgoing behaviour
8
Q
environment
A
every aspect of the individual and her experiences other than the genes themselves
9
Q
epigenome
A
- heritable chemical changes to gene expression
- Epigenome tells genome when/how to work -> tells our cells which cells they should be (hair, heart, etc.) by turning them on/off
10
Q
chromosomes
A
- 46 chromosomes -> 23 pairs
- One chromosome from each pair comes from each parent
11
Q
DNA
A
- Genetic info made of long strings of DNA -> building blocks of genetic material
- DNA made of base pairs
- Every cell in your body has the same DNA
12
Q
if every cell in your body has the same DNA, why aren’t all your cells the same?
A
- Some genes are turned on/off at different points in development or at different locations to create different cell types, etc.
- Ex. Genes that are responsible for secondary sex characteristics are present throughout the life time, but aren’t turned on until puberty
- Ex. Genes that are responsible for red blood cells are never turned on in hair cells
13
Q
5 types of nature/nurture interactions
A
- Parent’s genotype -> child’s genotype
- Child’s genotype -> child’s phenotype
- Child’s environment -> child’s phenotype
- Child’s phenotype -> child’s environment
- Child’s environment -> child’s genotype
14
Q
Parent’s genotype -> child’s genotype
A
- Variations in genetics amongst children from the same parents
- due to random assortment, crossing over, and/or mutations
15
Q
random assortment
A
- You only get 1 chromosome for each pair from each parent, and whichever one you get is random
- Chromosomes are shuffled in the process of gamete (egg and sperm) formation
- Unlike all our other cells, gametes only have 23 chromosomes
- Results in 2^23 possible combinations -> chances are genetically 0 that two sperms/eggs will be the exact same
16
Q
crossing over
A
Division of germ cells in embryonic development results in shuffling of DNA sections
17
Q
mutations
A
- Errors in DNA transcription
- Some mutations are invisible, but some create inviable gametes/fetuses (resulting in fetal death), or maladaptive characteristics
- A minority of mutations are adaptive rather than maladaptive -> result in gradual evolution of the species
18
Q
Child’s genotype -> child’s phenotype
A
- Although every cell in the body contains all of an individual’s genetic material, only some of those genes are expressed at a given time
- Some are switched on during cell differentiation (eg. To form limbs, brain cells, blood cells)
- Activated/deactivated by regulator genes
- Some recessive genes are never expressed at all
- Most of the differences between humans are due to gene expression, not genetic differences (1-1.5% variation in the population)
19
Q
Child’s environment -> child’s phenotype
A
- Norm of reaction: the range of all phenotypes that could theoretically result from one given genome
- Growing up in a rich vs. Impoverished environment can influence the expression of genes
- Ex. Genetic predisposition to be taller than average, but undernourished as an infant -> end up at average height
- Ex. Genetic predisposition to be extroverted, but experience trauma as an infant -> introverted
Genetic experiences put you in a certain range, but your experiences move you up or down in the range
20
Q
Child’s phenotype -> child’s environment
A
- Reflects the active child theme
- Children change their own environments based on their phenotypes
- Ex. A child with a predisposition for low sustained attention may choose activities that require less attention
- Ex. Choosing to be active and play outside rather than sitting in once place and reading a book
21
Q
Child’s environment -> child’s genotype
A
- Environment can cause changes in gene expression
- Epigenetics
- Gene silencing: methylation (addition of methyl group to DNA) prevents transcription
- While one’s genome is constant throughout lifespan, the epigenome changes
22
Q
shared genome in humans
A
- Humans share 99% of the human genome
- Gene expression is what changes in order to make us different from each other
- Allows us to have genetic similarities but phenotypic differences
23
Q
epigenetics
A
- The fifth type of nature-nurture interaction (child’s environment – child’s genotype)
- Experience mother has affects genetic expression in offspring, and that epigenetic change is inheritable by the next generation
- Genetic expression = turning on/off
- Can change during critical periods (ie. Pregnancy, puberty)
