Physiology is the study of an organisms parts and functions.

A physiologist would study how the human arm moves when throwing a ball.

A fellow worker, mainly in the professional work environment.

Discipline with this context is used to describe the general outline of a person's study.

Deposition, in science, is the addition or building up of a substance.

Perturbation is the act of an object or subject being "pushed" off of it's normal path. A small setback and/or a sudden change of plan.

An example of perturbation in a biological setting would be a limb being torn off of a tree.

To do something profligately is to do spend something fast and unwisely. An example of doing something profligately is to spend large amounts of money on luxury: while being fun, you may regret it at a later time.

A detritivore is an organism that feeds off of the dead remains of another organism. The most common example of a detritivore is worm.

A permeable object allows the flow of liquids and gases, such as oxygen.

A less permeable leaf would restrict the flow of oxygen and carbon dioxide greatly.

An ecologist is a person who studies the environment and all organisms living in it. They also study the relations between the environment and the organisms.

Photosynthesis is the process of turning sunlight into glucose. This process is used by almost all plants as means to store energy.