Which of the following is a role of lymph nodes?
they return lymph to circulation.
they produce lymph.
they filter lymph.
they produce red blood cells.

They filter lymph.

Explanation: Lymph nodes filter lymph, a fluid that comes from the blood plasma and passes through the lymph nodes; small structures that consist of immune cells. Their function is to engulf foreign parcticles. They prevent these foreign matters from circulating in the blood stream, playing a very important role in the immune system.

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.