Chapter 3

Question 1

Genotype:

Answer 1

Genetic endowment that an individual inherits

Question 2

Phenotype:

Answer 2

Ways in which a persons genotype is expressed in observable or measurable characteristics

Question 3

Epigenetics:

Answer 3

Dynamic operation that changes a gene without altering the DNA sequence

Question 4

Conception:

Answer 4

Moment of fertilization, when a sperm penetrates an ovum, forming a zygote

Question 5

Mitosis:

Answer 5

Process in which a cell duplicates its chromosomes and then divides into two genetically identical daughter cells

Question 6

Gonads:

Answer 6

Sexual organs that produce germ cells; testes and ovaries

Question 7

Meiosis:

Answer 7

Process in which a germ cell divides, producing gametes (sperm or ova) that each contain half the parent cell’s original complement of chromosomes; in humans the products of meiosis contain 23 chromosomes

Question 8

Autosomes:

Answer 8

The 22 pairs of human chromosomes that are identical in males and females

Question 9

How do genes promote development?

Answer 9

• Call for production of AAs, which form enzymes + other proteins necessary for formation and function of new cells
• guide cell differentiation
• regulate pace and timing of development

Question 10

What are experience-expectant interactions?

Answer 10

Effects of the external environment that are experienced by all humans

Question 11

What are experience-dependent interactions?

Answer 11

Effects of external environment that are experienced by only some people

Question 12

What are the 3 main patterns of genetic inheritance involving single genes?

Answer 12

• Simple dominant-recessive inheritance
• codominance
• sex-linked inheritance

Question 13

Alleles:

Answer 13

Alternative forms of a gene at a particular site on a chomosone

Question 14

Simple dominant-recessive inheritance:

Answer 14

A pattern of inheritance in which one allele dominates another so that only the dominant phenotype is expressed.

Question 15

Homozygous:

Answer 15

Having inherited 2 alleles for an attribute that are identical in their effects

Question 16

Heterozygous:

Answer 16

Inheriting 2 alleles for an attribute that have different effects

Question 17

Carter:

Answer 17

A heterozygous person who shows no sign of a recessive allele in their own phenotype but can pass this gene to offspring.

Question 18

Codominance:

Answer 18

2 heterozygous but equally powerful alleles produce a phenotype in which both genes are fully & equally expressed

Question 19

Incomplete dominance:

Answer 19

When one of 2 heterozygous alleles is stronger than the other but fails to mask all its effects

Question 20

Sex-linked characteristic:

Answer 20

An attribute determined by a recessive gene that appears on the X chromosome, more likely to characterize males

Question 21

Polygenic trait:

Answer 21

A characteristic that is influenced by the action of many genes, not just a single pair.

(Examples: height, weight, IQ, skin colour, susceptibility to cancer)

Question 22

Methylation:

Answer 22

• One of most common epigenetic processes
  -the addition of 1 carbon and 3 hydrogen molecules to a regulatory region of the DNA
  -usually turns the gene off; obstructing the expression

Question 23

Congenital defects:

Answer 23

Those that are present at birth (though many conditions are not detectable at birth)

Question 24

Trisomy:

Answer 24

• Most common type of autosomal abnormality
• occurs when an abnormal sperm or ovum carrying an extra actosure combines with a normal gamete to form a zygote with 47 chromosomes

Question 25

Dev. Implications of Turner syndrome (XO)

Answer 25

Female; small statues webbed neck; broad deist small, underdeveloped breasts; lack normal sexual development @ puberty; normal verbal intelligence but below average spatial abilities

Question 26

Dev. Implications of poly-x (superfemale) syndrome:

Answer 26

Female; fertile; below average iq; deficits in verbal reasoning; developmental delays become worse the higher the number of extra X chromosomes inherited

Question 27

Dev. Implications of Klinefelter syndrome:

Answer 27

Male, enlarged hips & breasts; very tall; sterile; underdeveloped tested; low in verbal intelligence

Question 28

Dev. Implications of super male syndrome:

Answer 28

Very tall; large teeth; severe acne as a teen; fertile; low sperm counts;

Question 29

Mutation:

Answer 29

Change in the chemical structure or arrangement of one or more genes that has the effect of producing a new phenotype

Question 30

Fragile - x syndrome:

Answer 30

Abnormality of X chromosome caused by a defective gene and associated with mild to severe intellectual disability, particularly when the defective gene is passed from mom to chid.

Question 31

Amniocentesis:

Answer 31

Method of extracting amniotic fluid from a pregnant woman so that fetal body cells within the fluid can be tested

Question 32

Chorionic villus sampling:

Answer 32

Alternative to amniocentesis. Fetal cells are extracted from the placenta for prenatal tests. Can be done earlier in the pregnancy than is possible with amniocentesis.

Question 33

Non-invasive prenatal testing:

Answer 33

Cell-free DNA (cfDNA) from placenta is analyzed, reveals genetic profile of unborn child.

Question 34

PKU:

Answer 34

Phenylketonuria: genetic disease where baby can’t metabolize phenylalanine; if left untreated, soon causes hyperactivity and intellectual disability.

Question 35

Heritability:

Answer 35

The amount of variation in a trait or a class of behaviour, within a specific population, that is attributable to hereditary factors.
(A calculated probability of how common a characteristic is among the population)

Question 36

In a family study, if the attributes of the individuals being compared are heritable, then _____

Answer 36

The similarly between any 2 pairs of individuals who live in the same environment should increase as a function of their kinship - the extent to which they have the same genes

Question 37

Twin design/twin study:

Answer 37

Study in which sets of twins that differ in zygosity (kinship) are compared to determine the heritability of an attribute

Question 38

Concordance rate:

Answer 38

% Of cases in which a particular attribute is present for 1 member of a twin pair if it is present for the other

Question 39

Heritability coefficient:

Answer 39

A numerical estimate, ranging from 0.00 to +1.00, of the amount of variation in an attribute that is attributable to hereditary factors.

Question 40

Non shared environmental influences:

Answer 40

Experienced unique to individual- not shared by other family members. Should make the individuals different from each other.

Question 41

Shared environmental influences:

Answer 41

Environmental influence that people living together share and that makes them similar to one another

Question 42

Canalizations:

Answer 42

Genetic restriction of phenotype to a small # of developmental outcomes; a highly canalized attribute is one for which genes channel development along predetermined pathways, so that the environment has little effect on the phenotype that emerges

Question 43

Range - of -reaction principle:

Answer 43

Genotype sets boundaries on the range of possible phenotypes that one might display to different environments.

Question 44

Evocative genotpe/environment interactions:

Answer 44

The notion that our heritable attributes affect others’ behaviour toward us and thus influence the social environment in which development takes place

Question 45

Passive genotype/ environment interactions:

Answer 45

Notion that the rearing environments that biological parents provide are influenced by the parents’ own genes, and thus are correlated with the child’s own genotype.

Question 46

Active genotype / environment interactions:

Answer 46

Notion that our genotypes affect the types of environment that we prefer and seek out

Question 47

How do genotype/environment interactions influence development?

Answer 47

Passive: important early in life
Active: important as child matures
Evocative: always important