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Flashcards in Chapter 3 Deck (26):

List and describe the 3 main arguments in Darwin's theory of evolution.

1. There is genetic variation in species.
2. Some genes aid adaptation more than others do.
3. Genes that aid their bearers in adapting to their environment will be passed to future generations more frequently than genes that do not.


For natural selection to work and for a species to evolve, what must be true of the genetic makeup of a species?

The genetic makeup must help the individual adapt to their environment in order to survive, reproduce and continue on their genes.


Complete this statement - "Genes do not determine anything..."

rather genes and environment interact and co-act to influence gene expression and in turn development and behavior throughout the life span.


Describe and give examples of the major mechanisms of inheritance.

Single gene pair - Each of thousands of human characteristics are influenced by only 1 pair of genes (one from mother, one from father).
Sex-linked - A characteristic is influenced by a single gene located on the sex chromosone. Example: red/green color blindness caused by recessive gene on X chromosone.
Polygenic inheritance - human characteristics influenced by multiple pairs of genes interacting with multiple environmental factors. Examples: height, weight


What happens to gene expression when a dominant gene is paired with a recessive gene?

The dominant gene will be prominent.


What is the most likely outcome for a zygote with the wrong number of chromosones?

Most likely outcome is spontaneous abortion. If the case of 3 chromosone 21, Down syndrome.


Review twin studies, adoption studies and family studies.

Important to review information on pages 73-75


What are concordance rates and what do they tell us about the trait being studied?

The percentage of pairs of people studied (i.e. identical twins) in which if one member of a pair displays the trait, the other does to. If concordance rate is high, the trait is heritable.


Describe molecular genetics and explain what molecular genetics studies tell us that behavioral genetics studies cannot.

Molecular genetics is the analysis of particular genes and their effects. Allows researchers to study the effects of specific genes in combinations with the effects of specific environmental influences.


Compare the heritability of intelligence and temperment and personality.

Genes contribute to individual differences in temperment and personality and heritability of intelligence.


Describe and give an example of passive gene-environment.

The environment the child is exposed to correlates with their genotype. Example: child receives "sociable" gene and lives in a household where parent's entertain often.


Describe and give an example of evocative gene environment.

Child's genotype evokes certain reactions from others. Example: Smiling and cooing baby elicits smiles.


Describe and give an example of active gene environment.

Child's genotype influences the type of environment they seek out. Example: Extrovert genotype is likely to party and be more socially involved.


Explain what epigenetic effects are and what they say about the relationship between genes and environment.

These are ways in which environmental factors influence the expression of particular genes in particular cells.


Explain why genetic research and behavioral genetic research are controversial.

Can lead to more pregnancy terminations in order to achieve a "super baby".


Species hereditary

The genetic endowment that members of a species have in common especially genes that influence development and aging processes.


Crossing over

A quirk of meiosis before chromosones separate.


Incomplete dominance

Results in a blend of traits



The beginning of a human; conception



The proportion of all the variability in the trait within a large sample of people that can be linked to genetic differences among them.


Identical twin

Results when one fertilized ovum divides to form 2 or more genetically identical individuals.


Fraternal twin

Results when two ovums are released at the same time and are fertilized by a different sperm



The genetic makeup a person inherits



The characteristic or trait that the person eventually has


Gene environment interaction

The effects of our genes depend on what kind of environment we experience and how we responde to the environment depends on what genes we have.


Gene environment correlation

The ways in which a person's genes and his environment or experiences are interrelated - active, passive, evocative.