Lab Safety Rules
0 See handout from yesterday
0 Check out this rap
What is Biology?
0 Biology is the science that seeks to understand the
living world.
How can we define “life”?
Characteristics of Living
Things
0 Made up of units called cells
0 Can reproduce
0 Are based upon a universal genetic code
0 Can grow and develop
0 Obtain and use nutrients and energy
0 Respond to their environment
0 Maintain a stable internal environment
0 Change over time (as a group)
Made of Cells
0 Cell: collection of matter enclosed by a
barrier that separates the cell from its
surroundings
0 Unicellular: made of one cell
0 Multicellular: made of more than one cell
Reproduction
0 Produce new organisms
0 Sexual reproduction: cells from 2
different parents unite to form offspring
(meiosis)
0 Asexual reproduction: offspring has as
single parent (mitosis)
Universal Genetic Code
0 Asexual reproduction—offspring and parent
have same traits
0 Sexual reproduction—offspring differ from
parents in some ways
0 Genetic code=DNA
0 All living organisms follow this code
0 Determines your inherited traits
Growth and
Development
0 Can lead to an increase in size,
a change in form, or an increase in #
Obtain Nutrients and Energy
0 Metabolism: (sum of an organism’s life processes)
0 The combination of chemical reactions through which
an organism builds up or breaks down materials as it
carries out its life processes
0 Autotrophs: obtain energy directly from sunlight
0 photosynthesis
0 Heterotrophs: obtain energy by consuming other
organisms
0 respiration
Respond to Environment
0 Detect and respond to stimuli from their environment
0 Stimuli: a signal to which an organism responds
0 i.e. switching classes when the bell rings,
0 pulling hand off a hot stove,
0 asking for a mint when you hear a computer restart
0 Stimuli may be internal or external
0 Internal—regulating blood sugar
0 External—seeds germinating when soil is moist
Maintain a stable internal
environment
0 Homeostasis: process by which organisms maintain a
stable internal environment
0 Usually involves feedback mechanisms
0 Such as the blood sugar example
0 sweating
0 Think of a thermostat
Maintain a stable internal
environment
0 This is the Regulation in RRREGENTS
0 Body systems included:
0 Endocrine system—hormones
0 Nervous system—uses nerve cells
Concept Map
0 Work in groups to connect the words into a web that
all stems from “Biology”
Quick Lab
0 Materials: hand lens, unknown objects (dry), same objects
soaked in water
0 Procedure:
0 1. Examine the dry unknown object in jar A. Record your
observations.
0 2. Predict what you expect to see when the same object is
soaked in water
0 3. Examine the object that has been soaking in water for a
period of time in jar C. Record your observations. Wash your
hands.
0 Conclusion: Which of these objects were alive?
15 minutes
Levels of Organization
Viruses, Bacteria, Prions,
Ribosomes, and Cells
0 Read the brief passage about each of these, and
characterize each as living or non-living.
(15-20 minutes)