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.
Every cell of the human body that has a nucleus has ____ chromâ¦. Sperm cells and egg cells are called: Gametes contain only ______ chromosomes each. When a sperm cell and an egg cell join (fertilization) they coâ¦. 46. Every cell of the human body that has a nucleus has ____ chromâ¦. Gametes. Sperm cells and egg cells are called: 18 terms.