The functional unit of the human kidney is the: MCQ with Answer and Explanation

Explanation:
Smooth endoplasmic reticulum (SER) lacks ribosomes and is the site of lipid synthesis, including phospholipids and steroids. It also detoxifies drugs and poisons. Rough ER synthesizes proteins, Golgi modifies and packages molecules, lysosomes degrade waste. SER is abundant in cells producing steroid hormones.

Explanation:
Chromosomes consist of DNA wrapped around histone proteins. Somatic cells have 46 chromosomes (23 pairs), gametes 23. A karyotype is a picture of chromosomes, not sequence.

Explanation:
Charles Darwin, an English naturalist, proposed the theory of evolution by natural selection in his seminal book 'On the Origin of Species' (1859). His theory, based on observations from his voyage on the HMS Beagle (especially the Galapagos finches), states that species evolve over time through the process of natural selection, where individuals with advantageous traits are more likely to survive and reproduce.