Chapter 2 - Biological Beginnings

Question 1

Evolutionary Psychology

Answer 1

Branch of psychology that emphasizes the importance of adaptation, reproduction and “survival of the fittest” in shaping behaviour

Question 2

Chromosomes

Answer 2

Threadlike structures that come in 23 pairs, with one member of each pair coming from each parent. Chromosomes contain the genetic substance DNA.

Question 3

DNA

Answer 3

A complex molecule that contains genetic information.

Has a double helix shape (like a spiral staircase)

Question 4

Genes

Answer 4

Units of hereditary information, are short segments of DNA

Question 5

Mitosis

Answer 5

Cellular reproduction in which the cell’s nucleus duplicates itself with two new cells being formed, each containing the same DNA as the parent cell, arranged in the same 23 pairs of the chromosomes

Question 6

Meiosis

Answer 6

A specialized form of cell division that forms eggs and sperm (gametes)

A cell of the testes or ovaries duplicates its chromosomes but then divides twice, forming 4 cells, each of which has only half of the genetic material of the parent cell. By the end of meiosis, each egg/sperm has 23 unpaired chromosomes

Question 7

Fertilization

Answer 7

A stage in reproduction during which an egg and a sperm fuse to create a single cell, called a zygote

Question 8

Zygote

Answer 8

A single cell formed through fertilization

Question 9

Genotype

Answer 9

A person’s genetic heritage; the actual genetic material present in each cell

All of a person’s genetic material makes up their genotype

Question 10

Phenotype

Answer 10

The way an individual’s genotype is expressed in observed and measurable characteristics

Consists of observable characteristics

Include physical characteristics (height, weight, hair colour) and psychological characteristics (personality, intelligence)

Question 11

4 genetic principles

Answer 11

Dominant-recessive gene principle, sex-linked genes, genetic imprinting, and polygenic inheritance

Question 12

Dominant-Recessive Gene Principle

Answer 12

One gene of a pair always exerts its effects; it is dominant, overriding the potential influence of the other gene, called the recessive gene

A recessive gene only exerts its influence if the 2 genes of a pair are both recessive

Question 13

Sex-Linked Genes

Answer 13

Most mutated genes are recessive. When a mutated gene is carried on the X chromosome, the result is called X-linked inheritance.

The implications for males may be different than those for females

Question 14

Genetic Imprinting

Answer 14

Occurs when genes have differing effects depending on whether they are inherited from the mother or the father

A chemical process “silences” one member of the gene pair

Example: only the maternally derived copy of a gene might be active, while the paternally derived copy of the same gene is silenced

Question 15

Polygenic Inheritance

Answer 15

When one characteristic is controlled by many 2+ genes

Few characteristics reflect the influence of only a single gene or pair of genes

Most characteristics are determined by the interaction of many different genes; they are said to be polygenically determined. Even simple characteristics, such as height, reflect the interaction of many genes, as well as the influence of the environment.

Question 16

Down syndrome

Answer 16

A chromosomal transmitted form of intellectual disability, caused by the presence of an extra copy of chromosome 21

Question 17

Klinefelter Syndrome

Answer 17

Chromosomal disorder in which males have an extra Y chromosome, making them XYY instead of XY

Question 18

Fragile X Syndrome

Answer 18

A genetic disorder involving an abnormality in the X chromosome, which becomes constricted and often breaks

Question 19

Turner Syndrome

Answer 19

A chromosome disorder in females in which either an X chromosome is missing, making the person XO instead of XX, or the second X chromosome is partially deleted

Question 20

Phenylketonuria

Answer 20

A genetic disorder in which an individual cannot properly metabolize an amino acid.

If left untreated results in intellectual disability and hyperactivity

Question 21

Sickle-Cell Anemia

Answer 21

A genetic disorder that affects the red blood cells and occurs most often in people of African descent

Question 22

Chorionic Villus Sampling

Answer 22

A prenatal medical procedure in which a small sample of the placenta is removed

Used to detect genetic defects

Question 23

What are some prenatal diagnostic tests?

Answer 23

• Ultrasound
• Fetal MRI
• Amniocentesis
• Chorionic villus sampling
• Maternal blood sampling
• Noninvasive prenatal diagnosis

Question 24

Ultrasound Sonography

Answer 24

Prenatal medical procedure where sound waves are directed into the woman’s abdomen

Echo from sound transforms into visual representation of the fetus’ inner structures

Question 25

Fetal MRI

Answer 25

Uses a magnet and radio images to generate detailed images of the body’s organs and structure

Question 26

Amniocentesis

Answer 26

Sample of amniotic fluid is withdrawn by a syringe and tested for chromosomal or metabolic disorders

Question 27

Behaviour Genetics

Answer 27

Field that seeks to discover the influence of heredity and environment on individual differences in human traits and development

Try to figure out what is responsible for the differences among people - to what extent people vary because of differences in genes, environment, or combination.

Behaviour geneticist’s often use twin or adoption situations

Question 28

Twin Study

Answer 28

The behavioural similarity of identical twins is compared with fraternal twins

Question 29

Adoption Studies

Answer 29

Investigators seek to discover whether, in behaviour and psychological characteristics, adopted children are more like their adoptive parents, who provided a home environment, or more like their biological parents, who contributed their heredity.

Can also compare adoptive and biological siblings

Question 30

3 Hereditary Environment Correlations

Answer 30

Passive, evocative, active (niche-picking)

Question 31

Passive Genotype-Environment Correlations

Answer 31

Correlations that exist when the natural parents who are genetically related to the child, provide a rearing environment for the child

Question 32

Evocative Genotype-Environment Correlations

Answer 32

Correlations that exist when the child’s genetically influenced characteristics elicit certain types of environments

EX: active, smiling children receive more social stimulation than passive, quiet children

Question 33

Active (niche-picking) Genotype-Environment Correlations

Answer 33

Correlations that exist when children seek out environments they find compatible and stimulating

Finding a setting that is suited to one’s genetically influenced abilities

EX: outgoing children seek out social contexts, shy children don’t

Question 34

Shared Environmental Experiences

Answer 34

Siblings’ common environment experiences, such as their parents’ personalities and intellectual orientation, the families economic status, and the neighbourhood in which they live

Question 35

Nonshared Environmental Experiences

Answer 35

The child’s own unique experiences, both within the family and outside the family, that are not shared by another sibling

Question 36

Epigenetic View

Answer 36

Theory that development is the result of an ongoing, bidirectional interchange between heredity and environment

Question 37

Gene X Environmental (G X E) Interaction

Answer 37

The interaction of a specific, measured variation in the DNA and a specific, measured aspect of the environment