Biology is the Study of All Forms of Life

“…from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. — Charles Darwin Dr James Rosindell, Imperial College London,

Two Main Groups of Life: Eukaryotes Prokaryotes Prokaryotes: single-celled mostly bacteria Eukaryotes: animals plants fungi protists Earth Has Amazing Biodiversity

All Life and the Places Where It Lives are called the Biosphere The biosphere includes many environments. The biosphere interacts with all other spheres: atmosphere, hydrosphere, lithosphere

Biodiversity is the collection of all life on Earth

Biodiversity increases from the equator to the poles Tropical rainforests have many species of plants and animals Temperate forests have less species than tropics Polar areas have only a few species

Heat map of the latitudinal biodiversity gradient terrestrial vertebrate species. Red colors indicate high biodiversity. Blue colors indicate low biodiversity. Source: Mannion et al. (2014), based on work by Clinton Jenkins. biodiversity-gradient/

What is a Species? A species is a single, particular kind of organism that can reproduce fertile copies of its same kind. It is estimated there are 8.7 million species on Earth. So far, only about 1.3 million have been identified and named. Psychedelic frogfish (Indonesia, 1999) Caqueta titi monkey (Southern Columbia, 2010) Yeti crab (2006) Blossom Bat (New Guinea)

What are Organisms? Organisms are individuals of a species. They are any single living thing. Examples of organisms: – person, shrimp, bacterium, squirrel, bee, plant All organisms have one or more cells – Many bacteria are single-celled – All animals, plants, and fungi have many cells

All organisms share four common characteristics (according to our textbook) 1.They are made of one or more cells. 2.They all require energy for metabolism. 3.They all respond to or interact with their environment. 4.They all contain DNA that they pass on to their offspring.

All organisms are made of cells Some organisms (like bacteria) are made of only one cell: unicellular Many more types of organisms are made up of many cells: multicellular In multicellular organisms, cells have different functions, e.g. muscle cells, skin cells, lung cells, etc. Cells are organized into tissues and organs with different structures for different functions

All cells need energy All living things use chemical energy Plants collect energy from the sun and use it to make their own chemical energy (sugars) Animals get energy from eating plants or other animals and breaking them down to derive chemical energy Energy is required for metabolism: the chemical processes that make or break down materials.

All organisms respond to their environment Respond to stimuli such as light, temperature, touch Organisms may do different things in response to changes in their environment Non-living things (e.g. rocks, chopped wood) don’t respond to their environment

All organisms reproduce and go through stages of development Unicellular organisms reproduce when one cell divides into two Multicellular organisms by either – asexual reproduction (one individual forms another) – sexual reproduction (two individuals combine genetic information to produce offspring) All reproduction involves passing on an organisms DNA to its offspring

All organisms share four common characteristics 1.They are made of one or more cells. 2.They all require energy for metabolism. 3.They all respond to or interact with their environment. 4.They all contain DNA that they pass on to their offspring.