However, human activities generate additional 'greenhouse gases'. Globally, atmospheric concentrations of two of the main greenhouse gases, carbon dioxide (CO2) and methane (CH4) have increased over the last 150 years. Agriculture has played a significant role in this-up to 35% of anthropogenic CH4 comes from animals and their wastes (Monteny et al. 2006).
sperm, sperm cell, spermatozoan, spermatozoon-the male reproductive cell; the male gamete; a sperm is mostly a nucleus surrounded by little other cellular material. egg cell, ovum-the female reproductive cell; the female gamete.
Sex cell are called gametes in biology. Sex cells are special type of cells which reproduce inside reproductive organ in male and female. Male gametes are called sperm and female gametes are called eggs. Jawad Â· 12 months ago. Thumbs up. 2. Thumbs down. 1.