Explain how scientists have deduced that life on Earth began 3.9 bya

Which class of molecules contains the amino group, nh2 (a) sugars (b) water (c) proteins (d) hydrocarbons

How are mutations continually being generated in a population (what are some of the causes of mutatuions? ) explain

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3: 1. if the allele are designated (r & r) receptively. what is the probable genotypes of the round seeds which produced f 1 ? rr & rr rr only rr & rr rr only rr only