CBSE Class 9 Answered

Anabaena is a cyanobacteria, belonging to phylum Monera. It is known for its nitrogen fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. Certain species of Anabaena have been used on rice paddy fields, proving to be an effective natural fertilizer.

Mycoplasma are smallest free-living organisms known to infect humans. Mycoplasma cause a variety of illnesses, especially of the lungs and sexual organs. They are very simple one-celled organisms without an outer membrane. They penetrate and infect individual cells. Most commonly, mycoplasma causes pneumonia.

Appendage is a part or organ, such as an arm, leg, tail, or fin, that is joined to the axis or trunk of a body. It is an external body part, or natural prolongation, that protrudes from an organism's body, such as a vertebrate's limbs. In invertebrate biology, appendage is a general term that covers any of the homologous body parts that may extend from a body segment. These include antennae, mouthparts, wings, walking legs, swimming legs, sexual organs i.e. gonopods, and parts of the tail i.e. uropods. Typically, each body segment carries one pair of appendages.