Assertion (A): Cilia and flagella are involved in cell movement. Reason (R): They contain microtubules arranged in a 9+2 pattern. MCQ with Answer and Explanation

Explanation:
Robert Hooke, in 1665, observed thin slices of cork under a compound microscope and saw box-like structures he named 'cells'. Leeuwenhoek observed live cells, Brown discovered the nucleus, Virchow proposed cells arise from cells.

Explanation:
Earthworm (Pheretima) belongs to phylum Annelida, characterized by metameric segmentation (body divided into segments), a closed circulatory system, and setae for locomotion. Tapeworm is a platyhelminth (flatworm), roundworm is nematode (Ascaris), Planaria is a free-living platyhelminth. Annelids include polychaetes (Nereis), oligochaetes (earthworm), and hirudinea (leech).

Explanation:
Dendrites are branched extensions of the neuron cell body that receive synaptic inputs from other neurons and transmit graded potentials towards the soma. The axon conducts action potentials away from the soma to the terminals, which then synapse with other cells. Dendrites have receptor sites for neurotransmitters.