Questions

In a plant, photosynthesis generally occurs in the leaves part as leaves have chlorophyll which is used for making food using sunlight.

Stokely Carmichael, a civil rights leader, used the term 'Black Power' to promote solidarity among African-Americans.

A rainbow is a natural spectrum appearing in the sky after a rain shower. It is caused by dispersion of sunlight by tiny water droplets, present in the atmosphere. A rainbow is always formed in a direction opposite to that of the Sun. The water droplets act like small prisms. They refract and disperse the incident sunlight, then reflect it internally, and finally refract it again when it comes out of the raindrops.

Auto-immune disease :: Sometimes, due to genetic and other unknown reasons, the body attack self-cells. This results in damage to the body and is called auto-immune disease.

From the options,

-> Rheumatoid arthritis is an autoimmune disorder in which antibodies are produced against the synovial membrane and cartilage.

-> Vitiligo causes white patches on skin also characterised as autoimmune disorder.

-> Psoriasis is a skin disease that causes itchy or sore patches of thick red skin and is also autoimmune.

-> Alzheimer's disease is a chronic neurodegenerative disease. Alzheimer's disease is due to deficiency of neurotransmitter acetylcholine.

Hence, Alzheimer's is not the auto-immune disease.