Chapter 1 Lesson 1

What is Science?

Science:  is an organized way of using evidence to learn about the natural world.

Key Point:

The goal of science is to investigate and understanding the natural world, to explain events in the natural world, and to use those explanations to make useful predictions.

Thinking like a scientist

Scientific thinking usually begins with observation, the process of gathering information about events or processes in a careful, orderly way.

The information gathered from observations is called data.

Explaining and Interpreting Evidence

A hypothesis is a proposed scientific explanation for a set of observation.

Chapter 1 Lesson 2

Forming a Hypothesis

Scholars of the day even gave a name to idea that life could arise from nonliving matter spontaneous generation.

Setting up a Controlled Experiment

   Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled.

   This type of experiment is called a Controlled experiment.

   The variable that is deliberately changed is called the manipulated variable.

   The variable that is observed and that changes in response to manipulated variable is called the responding variable.

How a Theory Develops

   As evidence from numerous investigations builds up a particular hypothesis may become so well supported that scientists consider it a theory.

   In science, the word theory applies to a well-tested explanation that unifies a board range of observations.

Chapter 1 lesson 3

Biology is the science that seeks to understand the living world.

What are the Characteristics of Living Things?

   Living things are made up of units called cells.

   Living things reproduce.

   Living things are based on a universal genetic code.

   Living things grow and develop.

   Living things respond to their environment.

   Living things maintain a stable internal environment.

   Taken as a group, Living things change over time.

   A Cell is a collection of living matter enclosed by a barrier that separates the cell from its surroundings.

In Sexual reproduction, two cells from different parents unite to produce the first cell of the new organism.

In Asexual reproduction the new organisms has a single parent.

   The Combination of Chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes is called metabolism.

   A Stimulus is a Signal to which an organism responds.

   The Process by which they do this is called homeostasis.

   The ability of a group of organisms to change over time is invaluable for survival in a world that is always changing. The process is called evolution.

Levels of Organization

         Biosphere

         Ecosystem

         Community

         Population

         Organism

         Group of cells

         Cells

         Molecules

Chapter 1 lesson 4

The Metric system is a decimal system of measurement whose units are based on certain physical standards and are scaled on multiples of 10.

Microscopes, such as the light microscopes in figures 1-25 are devices that produce magnified images of structures that are too small to see with the unaided eye.

Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magnified images by focusing beams of electrons.

Compound light microscopes allow light to pass through the specimen and use two lenses to form an image.

Electron microscopes is an microscopes that could look at smaller objects that you can’t see with your eyes such as the one shown in figure 1-26 use beams of electrons rather than light, to produce images.

The cell is able is to reproduce so that a group of cells, called a cell culture, develops from the single original cell.

Biologists often use a technique known as cell fractionation to separate the different cell parts.

To refresh your memory please go to your biology book for the figures & pictures.