What important idea from thomas malthus inspired darwin?

Not 100%, But in my biology class we discussed this at the beginning of the year. Darwin believed in survival of the fittest. Thomas Malthus believed that there are a lack of resources (food) because of over population.

The name of the instrument that the scientist uses is called a microscope.a microscope is used to view objects which is not visible to the naked eyes

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.