All animals, either directly or indirectly, depend on plants, sunlight, water, soil and air. All animals, including people, pets and wildlife need food, water, shelter and space in which to live. These things must be present in the quantity and quality required by that particular animal. Because animals need food, water, shelter and space to be available in a way that is suitable to their needs, we say that these things must be available in a suitable “arrangement.”
When the ground is saturated or impermeable to water during heavy rains or snow melts, excess water flows over the surface of land as runoff. Eventually, this water collects in channels such as streams. The land area that drains water into the channels is called the watershed or drainage basin.
The Earth has been called the water planet. Between two-thirds and three-fourths of its surface is water. The Earth’s water can be seen in flowing rivers, ponds, lakes, oceans, locked in the northern and southern ice caps, and drifting through the air as clouds. Water that has seeped into the Earth’s crust (groundwater) is more difficult to see, yet all these forms of water are part of a dynamic, interrelated flow that we call the water cycle.
Much of the waste produced by people ends up in the oceans. Some of it is dumped there, but most of it is washed off the land and into the ocean through our watersheds flowing into creeks and rivers. Because water quality affects which organisms can survive in a body of water, the types of organisms present in a water source indicate the quality of the water. The number of organisms present within an environment is also a good indicator of the quality of the environment in which they live. In good conditions, there should be a diverse and abundant community of macro-invertebrates.
The Earth is made up of several layers. These layers vary in thickness, density and composition. Each layer has specific properties that affect the Earth’s motion and the constant changing properties of our environment.
Many theories have been presented that try to explain the movement of land areas over the Earth. Alfred Wegener presented one of these theories that was widely accepted by scientists over the years. Even though he had a lot of evidence, he was never able to explain the colossal force that would have been needed to push the continents over the surface of the Earth.
Further investigation led to scientists investigating the ocean floor. They found deep ocean trenches that were all linked together. These trenches outlines huge blocks of the Earth’s surface, called plates. Continental crust is made up of granite (which is lighter) and oceanic crust is made up of basalt (which is much heavier). It is believed that these plates carry the continents over the surface of the Earth. This theory states that the Earth’s crust is not stationary. It is constantly in motion. The Earth’s crust is being created and destroyed constantly through the movement of these plates in different directions and at different rates.
The Animal Kingdom
In the 1700’s, a system of classifying organisms was developed. This classification system identified every animal that was known at that time. Scientists use eight basic groups to name all organisms on the Earth. These groups are: kingdom, phylum, sub-phylum, class, order, family, genus and species. All organisms must perform certain activities in order to stay alive.
In order to look at the minute differences that exist between organisms, scientist use magnification devices. These tools allow the observer to see similarities and differences that are important in accurately classifying organisms in our world.
All living things are place into five different groups called kingdoms. These groups are Animalia, Plantae, Fungi, Protista and Monera. Living things that are considered to be animals belong to either the Protista kingdom or the Animalia kingdom. The protista kingdom contains the smallest of all animals, the protests. All other animals belong to the Animalia kingdom. All multi-celled animals can then be placed into two large groups, vertebrates and invertebrates. Vertebrates are animals with a backbone and invertebrates are animals without a backbone. The invertebrates are among the most numerous animals in nature. It has been suggested that 95% of all animal species in the world are invertebrates.
The Human Body
We sill be studying the various systems of the human body. Throughout our studies, we will focus on one system per week or two that will concentrate on the function an dparts of the various system and how all systems work together in order to create a heathy