According to the video, what are the two key ingredients to natural selection?

a. Predation and the environment
b. Reproduction and predation
c. Reproduction and variation
d. The environment and variation

C. Reproduction and Variation

Explanation:

Reproduction could cause gene and chromosomal mutations in the offspring therefore causing variation. The variation could either helpful or detrimental to the offspring depending on the environment and if it helps them live or not.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.