All organisms have dna, which differs only in the number and order of each type of nucleotide. this suggests that all organisms have
a) a common ancestor.
b) the same amount of dna.
c) the same types of proteins.
d) a common reproductive cycle.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.