Opener #1 Science of Biology
1. What are the two types of data and
explain the difference?
2. What are the steps in the scientific
method?
3. What are the characteristics of life?
4. What is the process of maintaining a
stable internal environment called?
5. What is metabolism?
Unit 1: The Nature of Life
Chapter 1
The Science of Biology
What is Science
The goal of science is to investigate and
understand the natural world, to explain
events in the natural world, and to use
those explanations to make useful
predictions
Science is an organized way of using
evidence to learn about the natural world.
Scientific Thinking
Scientific thinking usually begins with
OBSERVATION – gathering information
about events and processes…the
information gathered is called DATA
There are 2 main types of data: quantitative
data are expressed as numbers (resulting
from measuring or counting), and
qualitative data are descriptive and
involve characteristics that can’t be
counted or measured
Scientific Method
1. Ask a Question
2. Formulate a Hypothesis
3. Experiment
4. Recording and Analyzing Results
5. Draw and report conclusions
Theory
As evidence from numerous
investigations builds up, a particular
hypothesis may become so well
supported that scientists consider it
theory
A THEORY is a well-tested explanation
that unifies a broad range of
observations
Biology – the study of life
Characteristics of Living Things:
Living things…
1. Made up of units called cells
2. Reproduce
3. Are based on a universal genetic code
4. Grow and develop
5. Obtain and use materials and energy
6. Respond to their environment
7. Maintain a stable internal environment
8. Taken as a group, living things change over time
Made Up of Cells
Organisms are made up of small, selfcontained units called cells.
A cell is a collection of living matter
enclosed by a barrier that separates
the cell from its surroundings
Cells are the smallest units of an
organism that can be considered
alive
Reproduction
All organisms produce new organisms through a
process called reproduction
Two types of basic reproduction
1) Sexual Reproduction (Most Common) – cells
from two different parents unite to produce the
first new cell of the new organisms
2) Asexual Reproduction – the new organism has a
single parent. In some forms of asexual
reproduction, a single-celled organism divides in
half to form 2 new organisms
Based on a Genetic Code
Offspring usually resemble their parents.
With asexual reproduction, offspring and
their parents will have the same traits
With sexual reproduction, offspring differ
from their parents in some ways but there
are limits
The genetic code is carried by a molecule
called deoxyribonucleic acid, or DNA
Growth and Development
All living things grow during at least part of
their lives…for single-celled organisms
growth is mostly a simple increase in size;
while multi-cellular organisms typically go
through a process called development.
Need for Materials and Energy
An organism uses energy and a constant
supply of materials to grow, develop, and
reproduce. Organisms also need materials
and energy just to stay alive. 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.
Response to the Environment
Organisms detect and respond to stimuli
from their environment.
A stimulus is a signal to which an organism
responds
External stimuli, which come from
environment outside an organism (light,
temp, etc)
Internal stimuli come from within an
organism . (hunger, thirst, etc)
Maintaining Internal Balance
Even though conditions in the external
environment may vary widely, most
organisms must keep internal conditions,
such as temperature and water content,
fairly constant to survive.
The process by which they do this is called
HOMEOSTASIS.
Homeostasis often involves internal
feedback mechanisms that work in much
the same way as a thermostat.
Evolution
Although individual organisms experience
many changes during their lives, the basic
traits they inherited from their parents do
not change. As a group, however, any
given kind of organism can evolve, or
change over time. THIS TAKES A LOT OF
TIME!
Levels of Organization of Organisms
From least to most organized…
1. Molecules – group of atoms
2. Cells – smallest functional unit of life
3. Group of Cells - tissues, organs, etc
4. Organism – individual living thing
5. Population – group of organisms of one type living
together
6. Community – populations living in same area
7. Ecosystem – community and its non-living
surroundings
8. Biosphere – the part of Earth that contains all
ecosystems