Amoeba moves and captures food using temporary extensions of its cell body called: MCQ with Answer and Explanation

Explanation:
Auxins produced at the apex suppress the growth of lateral buds, maintaining apical dominance. Gibberellins induce rapid stem elongation or bolting in rosette plants before flowering. Cytokinins actually delay or prevent senescence (aging) of leaves by promoting nutrient mobilization, known as the Richmond-Lang effect. Therefore, statements 1 and 2 are correct, while 3 is false.

Explanation:
The Sinoatrial (SA) node, located in the right atrium, is the natural pacemaker because its cells are autorhythmic; they can spontaneously generate action potentials without external neural input. Crucially, the SA node has the highest intrinsic rate of depolarization (about 70-80 beats per minute) compared to other autorhythmic tissues like the AV node or Purkinje fibers. Therefore, it sets the pace for the entire heart, overriding slower pacemakers.

Explanation:
TMV was discovered by Ivanovsky. Viruses have a capsid. They require host cells to replicate, so 3 is incorrect.