Genetics & Evolution

Life Science

where is the genetic code for an organism stored?

in its deoxyribonucleic acid (or DNA)

organisms will always display a ________, but may sometimes carry a gene for a _____.

dominant trait; recessive trait

ie dominant brown eyes

what do Punnett squares do?

predict genotypes of offspring

What do capital and lowercase letters on Punnett squares represent?

capital: dominant gene

lower: recessive gene

Darwin’s Theory of Evolution

organisms have changed overtime to adapt to the unique and varied demands of their changing environments

Variants:

offspring with different traits from their parents

Traits can be

advantageous or disadvantageos

supporting evidence includes

fossil records, comparative anatomy and DNA sequences

Natural Selection

over time, beneficial traits are propagated and detrimental traits are eliminated

Accommodations

non-genetic changes, allowing individual organisms to respond to temporary changes in the environment

ex: when it’s cold outside, blood vessels contract to conserve heat, when it gets warmer, they will expand again, increasing blood flow.

Adaptations

changes at the genetic level, allowing a population to respond to long-term changes in the environment.

ex: trees get taller, giraffes necks get longer