L3

Question 1

DNA

Answer 1

2 strands of a sequence of 4 chemical bases (adenine, thymine, cytosine, guanine) arranged in complementary pairs

Question 2

Heredity

Answer 2

the transmission of genetic information across generations and how it translates to differences in physical characteristics and behavior

Question 3

Heritability

Answer 3

an estimate of the variability in the expression of a trait in a population that is attributable to genetic differences among those individuals

closer to 1 = genes account for variability

Question 4

Genes

Answer 4

sections of DNA that code for specific proteins

Question 5

Regulatory DNA

Answer 5

• regulates genes (on/off switch throughout life that can be built-in or influenced by the environment)
• malfunction can lead to regulator-gene defects

Question 6

Chromosomes

Answer 6

23 pairs (22 pairs of autosomes and a pair of sex chromosomes) which contain our DNA

Question 7

3 genetic processes that contribute to diversity

Answer 7

random assortment, crossing over, mutation

Question 8

Random assortment

Answer 8

one of each of the 23 pairs of chromosomes randomly goes to a new egg or sperm during meiosis, resulting in new combinations of chromosomes in offspring

Question 9

Crossing over

Answer 9

two members of a pair of chromosomes can swap sections of DNA during meiosis prior to random assortment

Question 10

Main difference between random assortment and crossing over

Answer 10

• diversity at the level of whole chromosomes
• diversity within chromosomes

Question 11

Mutations

Answer 11

random changes in genes within DNA

Question 12

Alleles

Answer 12

different variants of the same gene that we inherit from each of our parents (one on each chromosome)

e.g. eye color and blood type

Question 13

Autosomal dominant vs autosomal recessive

Answer 13

• only one allele is needed to express the trait in the phenotype
• both parents must pass the recessive allele for the child to express the trait

Question 14

Codominant alleles vs incomplete dominance alleles

Answer 14

• both are expressed (e.g. AB blood type)
• blend of alleles (e.g. curly hair from a combination of straight and wavy)

Question 15

Genotype vs phenotype

Answer 15

• unique genetic makeup of an individual (e.g. alleles)
• the way your genotype is expressed as influenced by the environment, or observable characteristics (e.g. height, IQ, personality)

Question 16

Norm of reaction

Answer 16

all the phenotypes that could theoretically occur from a given genotype across all possible environments

Question 17

Outcome of gene-environment correlations

Answer 17

kids become more like their genes due to their environments

Question 18

Passive gene-environment correlations

Answer 18

child’s genotype is reinforced by the environment created by the parents who share the same genotype

Question 19

Evocative gene-environment correlations

Answer 19

characteristics of the child elicit or evoke environments that support their genetic traits

Question 20

Active gene-environment correlations

Answer 20

child seeks out environments or experiences that support their genetic traits

a process called “niche-picking”

Question 21

Gene-environmental interactions

Answer 21

one’s genes make them particularly sensitive or susceptible to particular environments (e.g. PKU, MAOA)

Question 22

MAOA

Answer 22

• X-linked gene known to inhibit brain chemicals associated with aggression
• high MAOA activity = less aggression

Question 23

Methylation

Answer 23

epigenetic process wherein a methyl molecule binds to DNA and impacts (typically reduces) gene expression