1. Biology 111
Holyoke Walsh

2. What is Science??? Science
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3. Science is…
A body of knowledge that uses evidence to learn about the natural world.

4. What is Biology?
Biology is the branch of Science that deals with living organisms.

5. Copyright Pearson Prentice Hall
A Few Branches of Biology
Zoologists
Botanists
Paleontologists
Cell Biologists
Geneticists
Microbiologists
Ecologists
Copyright Pearson Prentice Hall 5

6. Scientific Inquiry
Biologists (like all scientists) make observations, ask questions and then try to answer them through research and experimentation.
What is the primary tool used by Biologists?

7. Scientific Method Ask questions, make observations Gather information
Form a hypothesis (If…then)
Set up a controlled experiment
Manipulated variable - the variable that is deliberately changed (aka independent variable) Responding variable is variable that is observed (aka dependent variable)
5)Record and analyze results
6)Draw a conclusion
7)Repeat & share findings
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8. HOMEWORK: Read Pages & Sections 1-1 and 1-2 and for Section 1-2 make notes on the various experiments outlined!

9. SpongeBob HWK
You are now going to work in partners if you wish to complete the worksheet on the scientific method.

10. Fill & Chill: 8 Characteristics of Living Things: Textbook 1-3 (page 15-17)
1) Life is Cellular- smallest unit of life unicellular = single celled (bacteria) multicellular = many cells (human)

11. 2. REPRODUCTION: Organisms Reproduce to Pass on their Genetic Traits

12. Two Types of Reproduction
Sexual Reproduction
Involves 2 parents
Egg (n) fertilized by sperm (n) to make a zygote (2n)
Offspring DIFFERENT from parents 12 12

13. Two Types of Reproduction
Asexual Reproduction
Involves a single organism or cell (2n)
Cell divides
Offspring IDENTICAL to parent (2n) 13 13

14. 3. Cells Have a Genetic Code (DNA/RNA)
copyright cmassengale 14 14

15. All organisms contain DNA
DNA (deoxyribose nucleic acid) carries the genetic code for all organisms
All organisms contain DNA
DNA codes for the proteins that make up cells & do all the work 15 15

16. 4. Organisms Grow & Develop16 16

17. 4. Growth & Development
Organisms grow by producing MORE CELLS & by cell ENLARGEMENT
Organisms develop as they mature into an adult organism 17 17

18. 5. Cells Require Food & Energy18 18

19. Food Requirements Autotrophs can make their own food
Photoautotrophs use sunlight to make food (photosynthesis) – ex?
Chemoautotrophs use chemicals such as iron & sulfur as their energy – ex? 19 19

20. Food Requirements Types of Heterotrophs: (cannot make own food)
Holozoic nutrition: Complex food is taken into a specialist digestive system and broken down into small pieces to be absorbed. This consists of 5 stages, ingestion, digestion, absorption, assimilation and elimination. ….includes herbivores/carnivores/omnivores
Saprozoic/Saprobes: Organisms feed on dead organic remains of other organisms.
Parasitism: Organisms obtain food from other living organisms (the host), with the host receiving no benefit from the parasite.
Mutualism: A symbiotic relationship between organisms, with each contributing and benefiting from each other. 20 20

21. Metabolism Sum of all the chemical reactions in an organism
All require energy
Sunlight is the ultimate energy for life on Earth 21 21

22. Metabolism Cellular Respiration
Cells releasing the chemical energy stored in foods
6O2 + C6H12O CO2 + 6H2O 22 22

23. 6. Organisms Respond to Stimuli
Organisms Respond to stimuli (Temperature, Water, Food Supplies, etc.) In Order To Survive & Reproduce 23 23

24. 7. Homeostasis
Keeping The Internal Environment of The Cell or Organism Within a balance necessary for life
Often called “equilibrium”
Stable internal conditions of pH, temperature, water balance, etc. 24 24

25. 8. Living Things Evolve
Groups Of Organisms (Not Individuals) Change Over Time In Order To Survive Changing Environments.
Fossil records show changes in groups of organisms 25

26. Biological Equipment
What is the most common tool used by biologists???

27. Leeuwenhoek
Father of Microbiology…made many imporvements in microscopy
made a simple microscope (mid 1600’s)
magnified 270X
Early microscope lenses made images larger but the image was not clear

28. MODERN MICROSCOPES
A microscope is simple or compound depending on how many lenses it contains
A lens makes an enlarged image & directs light towards you eye

29. A simple microscope has one lens
Similar to a magnifying glass
Magnification is the change in apparent size produced by a microscope

30. COMPOUND MICROSCOPE A compound microscope has multiple lenses
(ocular & objective lenses)

31. Do You Know The Parts? http://www.biologycorner.com/microquiz/#
Do you know how to focus a scope??
Make a dry/wet mount??
Put it away properly??

32. STEREOMICROSCOPE aka: dissecting microscope
creates a 3D image

33. TOTAL MAGNIFICATION
Powers of the eyepiece (10X) multiplied by objective lenses determine total magnification.

34. ELECTRON MICROSCOPES More powerful; some can magnify up to 1,000,000X
Use a magnetic field in a vacuum to bend beams of electrons
Images must be photographed or produced electronically

35. Scanning Electron Microscope (SEM)
Electron microscope image of a spider
produces realistic 3D image
only the surface of specimen can be observed
Electron microscope image of a fly foot

36. SEM cont…

37. Guess?
Toilet Paper

38. Guess??
Staple going through paper

39. Guess??
Mascara Brush

40. Guess??
Mosquito Head

41. Transmission Electron Microscope (TEM)
produces 2D image of thinly sliced specimen
detailed cell parts (only inside a cell) can be observed