Answer:
a. disruption of mitotic spindle formation.
Explanation:
Vinblastine is a chemotherapeutic drug which is used to restrict cancer cell proliferation. During metaphase, it binds to microtubular proteins which play a very important role in mitotic spindle formation. If spindles will not form then during anaphase, the sister chromatids will not separate and mitosis will not take place. This is how hyper-proliferative cancerous cells are controlled from dividing and cancer is treated using this drug.
Descriptive and inferential
The answer would be synaptic pruning.
The brain in children will have a much more synaptic connection than adults. This connection is important for learning process in the early stage of life. More synaptic connections allow multiple parts the brain areas to be connected even if there is a damage in one area.
The synapse will be cut down later in a process called synaptic pruning. Only the area that frequently used will be preserved.
When a cell needs energy it gets from the food that we eat and works like as usual.