Biology Chapter 1.1 The Study of Life

What is Biology?  Biology is the science of life. Biologist study all forms of living things, not just humans.

What do biologists do?  Work in labs.  Study animals and their natural environment.  Research diseases  Develop new medicines.  Develop new technology.  Solve problems.  Develop new plants.

Characteristics of Life All living things have certain characteristics. What makes something living? We call anything that is living or was alive an organism. The characteristics of life are: – Made of one of more cells – Displays organization – Grows and develops – Reproduces – Responds to stimuli – Requires energy – Maintains homeostasis – Adaptations evolve over time

Cell Structure  Cells are the basic units of life  Unicellular: made up of only one cell.  Multicellular: made up of many cells.  The type of cell is related to its function. For example heart cells make up a human heart.

How are living things organized Each cell is made up of atoms and molecules. Cells form tissue. Tissue forms organs. Organ systems work together to support an organism. For example, heart cells form heart tissue, heart tissue forms a heart, and the heart is part of the circulatory system that pumps blood through your body.

Growth and Development  Grow means to get bigger.  Development is the natural changes that take place during the life of an organism.  You are bigger at age 2 than age 1. That is growth.  You can talk and climb on things at age 2 when you could only walk and babble at age 1. That is development.

Reproduction  Reproduction is the production of offspring.  A species is a group of organisms that can breed with one another.  To continue to survive a species will have to reproduce.

Responding to stimuli  Stimuli is anything that is part of either environment that causes some reaction by an organism. You touch a hot stove, you scream. The hot stove is the stimuli that caused you to scream.  Response: the reaction to a stimulus.

Obtaining energy  All organisms must get energy to survive.  Living things get their energy from food.  Most plants and some unicellular organisms get their energy from the sun to make their own food.  Organisms that can not make their own food get their energy by consuming other organisms.

Homeostasis  Homeostasis is the regulation of an organism’s internal conditions to maintain life.  If an organism is upset processes to restore the organism to homeostasis occur or the organism may die.

Adaptation  Adaptation is any inherited characteristic that results from changes to a species over time.  Species change to make them better suited for their environment and more likely to survive.