VCE Biology- Unit 1

1. VCE Biology- Unit 1 AREA OF STUDY 1 Cells in action allaf.layal.l@edumail.vic.gov.au

2. Studying biology – the practice of science • The importance of observation What do we observe? • They way organisms function • Their interactions with each other and the environment. How do we observe? • Using our senses • A variety of instruments What are some observations that we can make about plants or animals?

3. Flying Blind – LazzaroSpallanzani and Bats

4. The Scientific Method • Hypothesis – Possible explanation (can either be supported or rejected by experiments) • If one hypothesis is supported by all the material then the hypothesis is then given the status THEORY or PRINCIPLE • Science can prove that something is wrong but it can not prove that a theory is correct in every single circumstance! • Experimental hypothesis must be testable, otherwise what’s the point? • You must ask the right question to get the right answer. Once you have a testable and relevant hypothesis then you must test it.

5. Methods and Results • Methodsmust be reliable – that means if someone else repeats it they get the same result. • There must be enough detail in your method so that someone else can repeat your experiment. • When running an experiment one must be objective rather than subjective. • Results for an experiment must be shown clearly and separate from a discussion (so without any interpretation). • In Science experiments must be repeated at least 3 times to make sure you didn’t get your result due to chance alone. • Results are checked using a p-test this tells us if there is less than 5% chance that your results were by chance

6. Experimental Controls • Experimental variables are things that can affect the result. • To eliminate experimental variables we use experimental controls.

7. Conclusions • After you have found your results from your experiment you can make conclusions. • Conclusions must be based on your results and other knowledge. • In the conclusion you only say things that you have shown in your experiment. • Speculation is going beyond the results and having your own explanations, this is fine but not in the conclusion.

8. Limitations • What are some limitations of the Scientific Method? • It can only be applied to hypothesis that can be tested. • It can only be used on questions that can be answered. • It can’t be used to test morality or ethics .

9. Organisms are living things • How do we know that something is living or non-living? • Animals: - respond, move, eat, reproduce • Plants: - grow, reproduce, obtain materials and energy • Mould: - Living and dead can also be used to refer to part of animals and plants.

10. Living or dead

11. Characteristics of organisms • Movement • Respiration • Sensitivity • Growth • Reproduction • Excretion • Nutrition

12. Evolution explain diversity • Evolution is a fundamental principle of biology. • The diversity of living things, their similarities and differences, the richness of the fossil record, the geographic distribution of organisms, the discovery of DNA and the genetic code and the ability to sequence and compare DNA all contribute to the understanding that all living things change and evolve over time. How is the interesting part. • Phylogeny is the study of evolutionary relationships. • Scientific classification is used to categorise animals based on their phylogeny.

13. Organisms are adapted to their environment • Different organisms have special features that help them live in their habitat. • Antarctic ice-fish have anti-freeze in their blood so that their blood doesn’t freeze. • Banksia seedlings are protected by a tough cone that only breaks during fires. • ADAPTATION – over time species become structurally, physiologically and behaviourally adapted to that particular environment. • The result of adaptation is natural selection.

14. Organisms are made up of cells • All living things are made up of cells – cells are very very small and there are many different kinds of cells within living organisms. (skin cells, brain cells, muscle cells) • Cells are the functional unit of all living things – This means that they are where all the action happens, they process food, give structure and many other things.

15. The Cell Theory • All organisms are composed of cells (and the products of cells). • All cells come from pre-existing cells. • The cell is the smallest living organisational unit.

16. Cell Structure • There are many types of cells and each has its own structure and purpose, so each cells has features that help it carry out its purpose. (e.g Nerve cells) • Despite cells having different functions, all cells have some things in common. • Plasma or Cell membrane. • Cytoplasm • DNA- genetic material • Organelles

17. Properties of cells • There are many types of cells and each has its own structure and purpose, so each cells has features that help it carry out its purpose. • Despite cells having different functions, all cells have some things in common. • Plasma or Cell membrane - separates the cell from it’s external environment. • Cytoplasm – Jelly like holds all the organelles, ions, salt, enzymes, nucleus and is 90% water. Cytosol is the fluid part of the cytoplasm. • DNA- genetic material that directs the cell’s activities. • Organelles – Components inside the cells cytoplasm that perform different functions.

18. Flagella and cilia Flagella- whip like tail Cilia- Hair like structures http://www.youtube.com/watch?v=gtIz1u8g1F0&feature=related http://www.youtube.com/watch?v=4GTfq2m-SnY&feature=related

19. Prokaryotes Vs Eukaryotes Eukaryotes (Eu meaning true) • More primitive cells • Lack membrane bound organelles • Smaller than Eukaryotic cells • Complex cells • Have membrane bound specialised organelles • Larger than prokaryotic cells

20. Prokaryotes • Classified in the kingdom Monera • Small and lack membrane bound organelles • Contain a single circular DNA chromosome found in an irregularly shaped region (nucleoid)

21. Eukaryotes • DNA is located inside the nucleus as thread like chromosomes • Specialised organelles each performing a specific function

22. Double Bubble MapComparing and Contrasting • From what you have learnt about Eukaryotes and prokaryotes draw a double bubble map and use it to compare the differences. Prokaryote Eukaryote

23. Organelles

24. Organelles

25. Cells and Microscopes • There are several types of microscopes, each can allow us to view cells differently and to a different degree. Iridium or gold platting

26. Slides and Microscopes experiment • Collect a light microscope and a slide from Layal • Place the slide gently under the microscope and focus in. • Draw an image of the cell you are looking at the highest magnification.

27. Organic and Inorganic compounds • Compounds are organized into 2 types: • Organic compounds – These are complex chemical compounds which contain Carbon and Hydrogen. • Inorganic compounds- These are all non-organic compounds. e.g. water, oxygen, nitrogen.

28. Inorganic components Water- most organisms are 70-90% water • Surface tension • Heat capacity • Cohesiveness Oxygen and carbon dioxide • Oxygen is needed for cells to release energy from food molecules • Carbon is the key molecule in organic molecules. Nitrogen • Nitrogen is needed to make proteins. Minerals • Are needed for the structural part of cells, the body and in enzymes and vitamins

29. Organic molecules Carbohydrates • Important source of energy • Made of carbon, hydrogen and oxygen Lipids • fats and oils important for energy stores and some structures. Proteins • Vital for all sorts of functions! Nucleic Acid • Genetic material for all organisms Vitamins • Required for normal functioning.