Biology Unit 1Intro to Biology

Unit 1 Objectives1. I can name and describe at least five of the

themes of life.2. I can identify and describe the following

parts of every scientific experiment, including: Control Independent Variable Dependent Variable

3. I can identify the parts of a microscope, and their functions.

4. I can use a microscope properly (including the concepts of magnification and resolution).

Target 1I can name and describe at least five of the themes of life.

Characteristics

•There are many characteristics that all living organisms have in common.

•Can you think of any? Let’s discuss them!

Six Elements!•99% of every single

living organism is composed of these six elements:

•C (Carbon)•H (Hydrogen)•N (Nitrogen)•O (Oxygen)•P (Phosphorus)•S (Sulfur)•Just remember,

CHNOPS!

Composed of Cells

•All organisms are made up of one or more cells.

Example• All the organisms you

see around you are multicellular

• That means they are composed of more than one cell

• Most of the organisms around you that you cannot see are unicellular

• That means they are composed of only one cell

Metabolism

•All living organisms must use energy to maintain their normal life functions.

Example• Living organisms that

make their own energy (from the sun or from chemicals) are autotrophic

• Living organisms that can’t make their energy and therefore must consume other organisms to meet their energy requirements are heterotrophic

Water•Water is essential

for life. Almost all biochemical reactions occur with or in water.

•Living things are made up of mostly water. You and I are about 66% water!

Respond to Stimuli

•All organisms will show a response to different stimuli.

Example #1

•A spider reacts to the vibrations made by a struggling insect in its web.

Example #2:Phototropism/Geotropism

•The leaves of the seedling grow upwards in response to light (phototropism)

•The roots of the seedling grow downwards in response to gravity (geotropism)

Example #3: Killdeer

•Do you know what unusual response it shows to an invader coming near its nest eggs?

•It pretends to have a broken wing, luring predators away from its nest. Then it flies away, returning to the nest at a later time.

Growth and Development

•All organisms grow and develop.

•We often call this their Life Cycle.

•Growth occurs by cell enlargement and/or cell division.

Cottontail Rabbits

Reproduction

•All organisms must reproduce to ensure the survival of the species.

• It often starts with courting…

Do you know what kind of turtle this is?

Snapping Turtle!

Do you know which one mates for life?

Canada Goose!

Adaptations

•A physical trait or behavior that gives an organism an advantage in its environment.

What Ohio animal is this? What adaptations does it have?

Muskrat!

•Webbed feet•Thick fur•Tail is flattened

vertically

Evolution

•Organisms go through changes which are passed on genetically to future generations.

Are the changes experienced by these goslings an example of evolution?

No! It’s an example of growth and development!

The State Fossil of Ohio!

•What is it?•Did this animal

experience significant changes over time?

•What happened to its kind (species)?

The State Fossil of Ohio!

•It’s a trilobite.•They did not

change much over millions of years.

•They are now completely extinct.

How many of the characteristics of living organisms can you remember without looking?!?

Themes of Life (for test!)•Biologists use these characteristics to come

up with the 7 themes of life:1. Cellular Structure and Function2. Metabolism3. Homeostasis4. Reproduction5. Evolution6. Heredity7. Interdependence

The ones not discussed…

•There were three themes on the previous slide that we have yet to discuss.

•Homeostasis: maintaining a stable internal environment.

•Heredity: Traits are passed from generation to generation.

• Interdependence: Different species are dependent on each other to survive.

Homeostasis Example #1

•Crocodiles sun themselves on rocks in the morning to increase their body temperature since they are cold-blooded.

Example #2• Blood sugar levels –

when your blood sugar is too high, it triggers your liver to work harder to process it; if your blood sugar is too low, your brain triggers your body to be “hungry”to increase it.

Heredity Example

•A parent passes on half of its genes to its offspring.

•This is why offspring will look similar to the parents.

Interdependence

•Symbiosis is a great example of interdependence. In symbiosis, different species are using each other to survive.

•There are 3 types: Parasitism, commensalism, and mutualism.

Parasitism

•Parasitism – when one species benefits and the other is harmed. (ex: tapeworm in intestines)

Commensalism

•Commensalism – when one species benefits and the other is neither harmed nor benefitted. (ex: barnacles on whales)

Mutualism

•Mutualism – when both species benefit; they are helping each other. (ex: flowers and their pollinators)

Time for a WS/Activity!What is Life? Lab, Which Theme Is It? WS, The Martian and the Car WS

Target 2I can identify and describe the following parts of every scientific experiment, including:

ControlIndependent VariableDependent Variable

Remember from previous science classes:

•A hypothesis is an educated guess about what will happen in an experiment.

•It is written as an if, then statement.

•Example: If I use a chemical fertilizer, then my plants will grow taller.

The “if” portion…•…refers to the independent variable!• It is what is changed in the setup of the

experiment.•Whatever “treatment” is used.•The one difference in the setup from group

to group.

• In our hypothesis: If I use a chemical fertilizer, then my plants will grow taller.

•So the chemical fertilizer is the independent variable!

The “then” portion…•…is the dependent variable!•It is what is measured in an experiment.•What change does the independent

variable cause?

•In our hypothesis: If I use a chemical fertilizer, then my plants will grow taller.

•So the height of the plants is the dependent variable.

Control Group

•In an experimental setup, the control group is the group that doesn’t receive the “treatment”

•It is used to compare (is my treatment making it better or worse than it would have been without the treatment?)

In an experiment for our hypothesis: If I use a chemical fertilizer, then my plants will grow taller.

•The control group would be the group of plants that didn’t get the chemical fertilizer.

•How do I know if fertilizer makes the plants grow taller if I don’t know how tall they would have gotten without any fertilizer?

Time for a WS and some activities!Practice Identifying Variables WS, Simpson’s Variables WS, Magic Fishy Lab, Surface Tension of Water Lab

Targets 3 and 4I can identify the parts of a microscope, and their functions.

I can use a microscope properly.

body tube

eyepiece (oculars)

revolving nosepiece

low power objective lens

medium power objective lenshigh power objective lens

stage clipsdiaphragm/condenserilluminator

arm

stage

coarse focus knob

fine focus knob

base

Time for some activities!How to Use a Microscope Online Tutorial, Introduction to the Microscope Lab