Science is the study of the natural world and everything inside of it. Science can study things like plant growth or animal hibernation because it occurs in nature and can be proven multiple times. Science can not study theological or supernatural things because you can not find them in nature or in the natural world and it cannot be proven multiple times.
The basic needs of every living thing are shelter, food, energy, the ability to change, and the ability to reproduce
The frog has many beneficial behaviors and structures. The frog has it's tongue attached to the front of its mouth so it can easily stretch its tongue to catch prey. It is an amphibian so it could escape from predators without having to worry about drowning. It has webbed feet so it can swim faster through water. The male frogs croak so they can attract females and warn males if they are in his territory.
One reason you might use a scientific model is that it is either too big or small to actually study. Another reason to use a model is because you can't study it directly because it could be too dangerous.
A system is a group of things that work together to complete a task. This can be related to the human body because we have several systems that work together to keep us alive.
This is a good representation of a system because there are a whole bunch of different components that work together to create a working computer.
Created with images by NASA-Imagery - "space shuttle lift-off liftoff" • jurvetson - "Keep Out Experiment In Progress — LIGO Gravitational Waves" • pixel2013 - "frog green green frog" • Melissa A. N. (Model) - "The Solar System Planets" • amitp - "New computer"