Intro to ‘Biology’ Biology – the science of life Organism – a “living thing”...

Intro to ‘Biology’

Biology – the science of life

Organism – a “living thing”

Therefore, biology studies organisms

∙ microscopic structure

∙ interaction among many

∙ life history

THEMES of BIOLOGY

• Evolution – change over time• Reproduction & Inheritance – DNA/Genetics

• Structure & Function – examples???

• Energy – required for life

• Ecology – interactions

Science & Society – conservation, bioethics, etc.

What is Life???Think about some of the things you see in your everyday life…

Animals Trees Rocks WaterSoil Buildings Cars

• You probably have an idea about which of these is alive and which are not.

• Scientists use the following characteristics to determine if something is alive or not. In order to qualify, the thing in question much possess all of the characteristics.

The Characteristics of Life:• made of cells• has organization• uses energy• responds to the environment• grows• reproduces

* Try applying these to the list above*

Use the word fragments in your list to figure out the meaning of the following terms:

1. Hydrology 11. Endocytosis

2. Cytology 12. Insecticide

3. Protozoa 13. Anaerobic

4. Epidermis 14. Bilateral

5. Spermatogenesis 15. Endotherm

6. Cytoskeleton 16. Subspecies

7. Abiotic 17. Arthropod

8. Dermatitis 18. Micrometer

9. Hypodermic 19. Hypothermia

10.Hemophilia 20. Photosynthesis

STRUCTURES AND FUNCTIONS

Write the correct term—autotroph or heterotroph—in the space referring to each of the organisms pictured below.

The Scientific Method

What is it used for???• Answering questions about the world around us• It does so in an organized and systematic way

THE STEPS OF THE SCIENTIFIC METHOD• Identify the problem/question• Observe• Form a testable hypothesis• Experiment (collect data)• Analyze data• Draw a conclusion • Repeat!

Experimental Design• Pre-planned series of steps• Goal is to collect (good) data• Most important part of the Scientific Method• “Controlled Experiment”

– Gathers data under controlled conditions– Comparison of two (almost identical) groups

Control Group: Receives the normal (control) treatmentExperimental Group: Receives the experimental treatment

Independent Variable: Only difference between groups“What did I change?”

Dependent Variable: Data gathered during experiment“What did I measure?”

Drawing a Conclusion• Analyze your data by creating charts/tables/graphs

• Look for patterns/trends • Your results should point towards a conclusion...

EITHER:

“the data collected supports… (the hypothesis)”

OR

“the data collected does not support… (the hypothesis)”

• THEORY: A statement widely considered to be true because it has been supported by extensive experimental evidence

Quantitative Data• Numerical information gathered through experimentation• Examples:

- tree branch length- cell count- colony diameter

• It is important for scientists to use a standard system of measurement

SI = international system of measurement (a.k.a. the metric system)

BASE UNITS: Length → meter Mass → gram Volume → liter

Metric Number Line

Metric ConversionsMetric Conversions1) 290,000.

2) 36.

3) 0.00007

4) 9.1

5) 10.6

6) 76.5

7) 104.9

8) 0.019

9) 0.396

10) 140.

11) 0.000025

12) 0.023

13) 0.000214

14) 5160.

15) 1.4

16) 0.2

17) 34.

18) 0.01

19) 27.6

20) 0.314

21) 41.17

22) 8,700.

Metric ConversionsMetric Conversions

23) 0.001

24) 7,100.

25) 0.0004

26) 146,100.

27) 0.0182

28) 22,100.

29) 0.0217

30) 0.0001087

Microscopy• A microscope produces an

enlarged image of an object

* MAGNIFICATION *

COMPOUND LIGHT MICROSCOPE• Used to view small organisms and cells• Thinly sliced specimen

mounted on a glass slide• 2 LENSES:

- Ocular (eyepiece)

- Objective (adjustable)• Total Magnification = ocular × objective

Compound Light Microscope Diagram

Compound Light Microscope Diagram

How to … MICROSCOPES!- If unsure, follow directions in your handout!

Read, read, read!!!- Handle the microscope with one hand on the arm

and the other giving support underneath the base- Always begin viewing under LOW power- Start with the lens as close to the

stage as possible, then pull away with the coarse knob until focused

- Once focused under low, switch to high power- Under HIGH power, only fine focus is needed

Answer all questionsMake 2 sketches for each slide viewed

Other forms of Microscopy

Light microscopes magnify with a beam of light

Electron microscopes do so with a beam of electrons

• TEM – transmission electron microscope• SEM – scanning electron microscope

Pro: Magnify many thousands of times

(instead of hundreds)

Con: Cannot view living specimens

Transmission Electron Microscope

TEM image of bacteria cells(magnified 50,000x)

SEM with opened sample chamber

SEM image of various types of pollen