The sliding filament theory explains how these cross-bridges are formed and the subsequent contraction of muscle. The Sliding Filament Theory For a contraction to occur there must first be a stimulation of the muscle in the form of an impulse (action potential) from a motor neuron (nerve that connects to muscle).
A plant scientist is a biologist who focuses on various types of plants, usually those grown as crops for food, fiber, and other purposes. This work can involve field and lab work on a variety of topics, from improving yields to developing more nutritious food plants for the purpose of fighting hunger in underdeveloped nations.
: This scientist studies living organisms and l iving systems. Botanist. : This scientist studies plants. Chief scientist. : This scientist leads other scientists in a particular research area. Ecologist. : This scientist studies the relationship of living things with their living and nonliving. environment. Economist. : This scientist studies economics. Economics is a social science that addresses the production, distribution, and use of goods and services. Fisheries biologist: This scientist studies fish living in the wild, including what they eat, their habitat, and how they interact with their environment.