The Characteristics of Life Cellular Organization Reproduction Heredity Metabolism Homeostasis Responsiveness Growth and Development

Cellular Organization All life is made up of one or more cells. A bacteria is made up of one cell, but plants and animals have even more. How many cells do humans have? 10 to 50 trillion cells! Each cell in the body does a special job, and working together they make an organism.

What kinds of cells are there?

Reproduction All organisms need a way to make more of themselves. There are a variety of different ways that organisms reproduce. Sexual Reproduction Eggs Live Birth Broadcast Spawning Asexual Reproduction Binary Fission Mitosis Fragmentation

Heredity All organisms pass traits on to their offspring. Your father’s nose, your mother’s hair are all traits that you have inherited from your parents. These traits are passed on through DNA. Every organism we know of in the world uses DNA to pass on it’s genetic code.

Metabolism Metabolism is a sum of all the chemical reactions in an organism. Metabolism is broken into two parts. Catabolism breaks down molecules and releases energy. Anabolism creates new molecules and uses energy. Anabolic steroids help build proteins which are added to muscles. All organisms require energy to do pretty much anything.

Homeostasis From greek, Homeo – the same, and Stasis – standing still. Homeostasis is a stable state of conditions in an organism’s body that are necessary for life. Body Temperature Water balance Blood pH

Responsiveness All organisms respond to things in their environment. We call these thing that organisms respond to stimuli. Light Temperature Odor Sound Gravity Heat Pressure

Growth and Development All organisms grow and develop. Development is a change in the physical or physiological make-up of an organism. Without growth, each generation would get smaller and smaller. Metabolism helps create the energy that fuels growth and development.

The Unifying Themes of Biology Cellular Structure and Function Homeostasis Metabolism Reproduction Heredity Evolution Interdependence

Evolution Evolution is the changes in the genetic makeup of a population over time. Every species undergoes evolution, however, some do it faster than others. Evolution acts on whole species, not on individual organisms. What is a species? A species is a group of organisms that are capable of interbreeding and can produce fertile offspring of both sexes.

What about hybrids?

Interdependence All organisms depend on other for survival. Or, as Elton John put it, there is a circle of life and it moves us all. The study of this interdependence between organisms and the environments in which they live is called ecology. This is one of the reasons environmental protection is so important, just like all other animals and life, humans rely on other organisms to live and thrive.