In the context of human reproduction, the 'Acrosome reaction' in the sperm is triggered when it comes into contact with the: MCQ with Answer and Explanation

Explanation:
Fungi are eukaryotic, mostly multicellular (except yeast), and are heterotrophic by absorption (saprophytic or parasitic). Their cell walls contain chitin. Monera are prokaryotic, Protista are unicellular eukaryotes, Plantae are autotrophic multicellular organisms. Fungi play key roles as decomposers in ecosystems.

Explanation:
Melanin, produced by melanocytes in the epidermis, is the primary pigment determining skin, hair, and eye color. It absorbs UV radiation, protecting DNA from damage. Keratin is a structural protein in hair and nails, collagen provides connective tissue strength, elastin elasticity. Albinism results from melanin deficiency.

Explanation:
Essential fatty acids are polyunsaturated fats that the human body lacks the enzymes to synthesize, so they must be consumed in the diet. The two primary essential fatty acids are linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid). They are precursors for other important lipids like arachidonic acid and are crucial for cell membrane structure and eicosanoid synthesis. Palmitic and stearic are saturated fats.