OBJECTIVE: INTRODUCE BIOLOGY AND REVIEW SOME PAST KNOWLEDGE. Lesson 1
ON THE WHITEBOARDS! Brainstorm about what you remember about cells What you know about them (choose a colour) What you sort of remember about them (choose a different colour) What questions you have about them. (choose a different colour) We share in 5 minutes!
SOME QUESTIONS FOR YOU How is our blood replaced if we get a cut and it starts to bleed? How does our skin heal a wound?
CELL THEORY The answer to these questions lies within all of us. Cell Theory All living organisms are composed of one or more cells Cells are the basic unit of structure and function in all living organisms All cells come from previously existing cells
SO HOW BIG? HOW MUCH? Cells are small, but not as little as the atoms we have previously learned. Although we can t see cells with our naked eye, the use of a microscope will allow us to view them Our body has over 35 trillion cells! This poses a pretty serious question. Why so small? And why so many?
Think about how hard it would be to replace one giant cell all at once rather than a couple of small cells at a time. WHY SO SMALL? WHY SO MANY? What do you think? Back to your whiteboards and brainstorm We need different cells for different functions The bigger the cell, the harder it is to control It is easier to replace small cells repeatedly than large ones
CELL PARTS FOR EUKARYOTIC CELLS There are two very broad categories of cells: Eukaryotic cells, and Prokaryotic cells. Eukaryotic cells are like you and me, plants and animals. They are complex organisms Prokaryotic cells are single celled organisms. Bacteria are prokaryotic cells In Grade 9 we will only talk about Eukaryotic cells since these are the cells that make up most of what we know for living organisms in the world. But later on, in Biology, you will learn more about Prokaryotic cells. For the rest of Grade 9 Science you can assume we are only talking about Eukaryotic cells
CELL STRUCTURE Within cells, there are many different parts that contribute to how cells function and operate. This is similar to our bodies how we have organs that help us function properly and carry out tasks so we can eat, sleep, think, etc. The cells have a version of organs within them called Organelles which means little organs The organelles have special functions that allows a cell to perform tasks and to survive Depending on what a cell does it might have more or fewer specific organelles. Some cells have special organelles that no other types of cells have. This is the big difference between an Animal cell and a Plant cell
TO THE WHITEBOARDS! Based on the next picture, write down what you think each number is representing. Bonus if you can remember what the organelles job is or make up a nickname for it!
6 1 5 3 2 Write down what you think each number is representing! 5 4 3 2 1 8 6 Bonus if you can remember the purpose or give a nickname for it! 4 7
THE ORGANELLES Nucleus The brain of the cell Controls all the cell functions and growth Houses chromosomes Cytoplasm Jelly like substance that holds all the organelles in place Allows the transport of nutrients and materials within the cell Chromosome Made up of DNA (deoxyribonucleic acid) Contains genetic information for the organism
ORGANELLES CONT Cell Membrane The outer covering of the cell Separates the contents inside the cell from the surroundings Controls the materials going in and out of the cell Vacuole Bigger in the plant cell (called Central Vacuole) Stores waste for the cell Cell Wall Only exists in the Plant cell Rigid outer layer outside the cell membrane Gives structure and support
DIFFERENCE BETWEEN ANIMAL AND PLANT CELL?
CELLULAR RESPIRATION Mitochondria in plant and animal cells absorb oxygen gas and use it to break down food for energy. FOOD + O 2 CO 2 + H 2 O Cells break down food and harvest the energy in it. They then give off Carbon dioxide gas and water as waste. Both plant and animal cells do this!
PHOTOSYNTHESIS Chloroplasts absorb the energy from light and use it to make a sugar molecule (glucose): CO 2 + H 2 O glucose + O 2 Plant cells manufacture sugar (glucose) so that they can store it away to use for energy later.
YOUR TASK Outcome Question #1 Definitions 1 4 can be filled out Why (when?) would Plant Cells use cellular respiration when they have photosynthesis available to produce energy for them? 5 point writing!***