Free Biology powerpoints

Free powerpoint presentations on Biology.

These powerpoint presentations have been made by teachers and experts for different topics of Biology. Please feel free to download and use.

Definition of Biology: 

Biology is the natural science that studies living organisms. DNA is the building block of life. Cells are formed from the cascade of events that occur such as transcription and synthesis of proteins from which the cells are built from. Single cell organisms exist, but multicellular organisms have evolved over millions of years. These animals and plants can be classified into many categories and humans are one of these. Like all more advanced lifeforms, humans have a complex range of bodily functions to regulate them. Energy is generated from ingesting food  which is broken down by enzymes to release this form of energy. Plants on the other hand use the power of the sun to capture the energy using photosynthesis. 

Fungi are distinct to both animals and plants. They exist as both multicellular organisms and single cell organisms (yeast). Cell wall composition is different to plants and animals. They contain chitin, a hard substance also found in the hard exoskeleton of some insects. When people think of fungi, they will usually think of the multicellular mushrooms we commonly see and buy from supermarkets. There are three major groups of fungi. 

Multicellular filamentous moulds, macroscopic filamentous fungi often referred to as mushrooms, and single celled mircroscopic yeasts. The ability of single cell organisms to assemble into multicellular organisms is a key characteristic of some fungi.