Nancy visits a local reservoir where she feeds ducks and other birds. Every time she feeds them she notices that they fight for the best pieces and some do not get any. All living things struggle to get the necessary amount of food, water, and shelter. What is the term for this struggle? A. overproduction
B. natural selection
C. variation
D. competition

Rarefaction is used for which of the following? a. creating a representative sample b. studying how disease impacts populations c. rediscovering species thought to be instinct d. determining which sea creatures live in an area

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.

People with one sickle cell allele are not likely to get malaria. what is this an example of?