Biological beginnings

How many genes do you inherit from each parent?

23 from the father and 23 from the mother

Sperm determines the sex

What are dominant and recessive genes?

Dominant: You only need one copy from one parents to display a trait

Recessive: You need two copies to show that trait

How can genetic inheritance affect development?

Dominant-Recessive pattern: where you get a dominant or recessive gene

Sex-linked inheritance: X-linked inheritance, since X chromosomes are more likely to be muted. Males most affected, since they only have one X chromosome

Polygenic inheritance: Traits are affected by many genes and the environment

Chromosomal abnormalities: Have too many or too few chromsomes

How do twin and adoption studies show the contribution of genetics and the environment?

Genes influence IQ: MZ reared-apart

MZ reared-together (the more genes you share, the more similar you are)

Environment influences IQ: MZ reared-together vs reared apart

Gene (heredity) -Environment Transactions (how do genes affect us):

Passive: Correction between your genes and environment. Child doesn’t have a choice in their environment

Active: The individual chooses the environment that fit their genes

Evocative: Your genes evoke a response from your environment

How does influence change along the lifespan?

When you’re younger, passive is more of an influence.

When you’re older, active is more of an influence.

Evocative affects you your whole life

Gene-Environment Interactions

Depending on your environment, a gene is most likely to develop Ex: depression

Environmental Influence on Gene Expression: What is the reaction range?

Range of all possible phenotypes (physical traits) that can result from a given genotype in different environments. The whole range can occur, but their is a limity

Ex: Plants have the same genes, but different ranges occur due to different environments.

your genes set the potential boundaries for a trait, but your environment determines where you fall within that range