Are the gases essential for life?

Name the organs of humanelemintary canal.

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

Which would be the most useful source of evidence to support mcneill's contention?