CELLS AND LIVING THINGS Read pp 388 396

CELLS AND LIVING THINGS

Read pp. 388 -396

CELL Smallest basic functional unit of life All living things are made up of one or more cells

FOUR CHARACTERISTICS COMMON TO LIVING THINGS All living things grow All living things move Movement involves changes to shape and position or can refer to legs and wings! All living things respond to stimuli in their environment Cell number increases and new cells replace old cells A stimulus is anything that causes a living thing to respond A cat hisses; your stomach rumbles All living things reproduce Produce more of their own kind (offspring)

EXAMINING VERY SMALL LIVING THINGS Anything smaller than 0. 1 mm the naked eye can’t see, so you need a microscope The microscope is used by scientists to observe very small unicellular and multicellular living things. Early microscopes were built in the late 1600’s. Anton van Leeuwenhoek was one of the first people to build a microscope. He could magnify up to 250 x, and used it to observe microscopic living things.

COMPOUND MICROSCOPE The compound light microscope has two sets of lenses that magnify an image. When you look through a microscope you see a magnified, inverted and reversed image. Each of the objective lenses has a different magnification power. Low power = 4 x objective Med power = 10 x objective High power = 40 x objective Multiply the objective by the eyepiece for total magnification. Example: High Power = 40 x 10 = 400 x

MICROSCOPE FOLDABLE Distribute a microscope image Add flaps to each part with the definition of each beneath the flap.

MICROSCOPE RESOLVING POWER The ability to distinguish between two dots or objects that are very close together is called resolving power. The human eye has a certain resolving power. You can see the individual dots in diagrams A, B and C. The human eye does not have the resolving power to see the dots in diagram D.

P. 397 Questions 1 -4

CORE LAB – SETTING UP AND USING A MICROSCOPE

Check your understanding Questions 1, 2, 3, 4, 5, 6, 7, and 9 Pause and reflect

Read pp. 402 -406

CELL PARTS An analogy is a way to understand new ideas by making a comparison. A factory can be used as an analogy for the cell. Parts of the cell that allow the cell to survive are called organelles. Organelles take up about 5 to 30 percent of the cell. The rest of the cell consists of water. Read pp. 402 -403 Do activity 10 -2 A, p. 404 (perhaps a class discussion)

THE FUNCTIONS OF CELL ORGANELLES The cell membrane protects the cell and selectively regulates the movement of particles in and out of the cell. Cytoplasm, the jelly-like substance within the cell, contains organelles, water, and other life supporting materials. The nucleus: � � controls all the activities within the cell. contains deoxyribonucleic acid (DNA).

ENERGY IN THE CELL The mitochondria are the organelles that produce energy in the cell. When the cell changes chemical energy, in the food we eat, to energy the cell can use, it is called cellular respiration. The total of all the chemical reactions that take place in our cells is called our metabolism. Cellular Respiration (c) Mc. Graw Hill Ryerson 2007

ORGANELLES FOR ASSEMBLY, TRANSPORT, AND STORAGE Proteins are essential for all life and are assembled by the ribosomes. Proteins then pass through the endoplasmic reticulum and are placed in vesicles by the Golgi body. Vacuoles are temporary storage compartments. Lysosomes break down food particles, cell wastes, and worn-out organelles. See pages 28 -29 (c) Mc. Graw Hill Ryerson 2007

THE DIFFERENCE BETWEEN PLANT AND ANIMAL CELLS Plant cells have two parts that are not found in animal cells: � Cell Wall protects the cell and gives cell shape � Chloroplasts change the Sun’s energy into chemical energy Other key difference is plants have on large vacuole whereas animal cells have several small vacuoles. Locate the cell wall and chloroplast See pages 29 -30 Photosynthesis

QUIZ!!!!

CELL THEORY The cell is the basic unit of life. All organisms are composed of one or more cells. All cells come from other living cells. (c) Mc. Graw Hill Ryerson 2007

PLANT AND ANIMAL ORGANELLES Organelle ~ structures of cells that perform a specific function Create a foldable of an animal and a plant cell Draw a typical plant cell on a large sheet of paper. Create flaps for each organelle with the definition of each underneath

CREATE A 3 D model of a cell (class activity) p. 407

LAB 10 -2 C Plant vs. Animal cells

DIVIDING CELLS Read p. 410 -411 All cells divide during their life cycle When cells divide, one cell becomes 2! Your skin cells divide to replace the cells you rub off or if you scrape yourself. When a cell divides, the genetic material duplicates and then divides into 2 identical sets of chromosomes – this is called mitosis. Each daughter cell (the new cells) gets one set of the duplicated genetic material. See figure 10. 10 Only exception to this type of division is your sperm cell and egg cells (more on this next year)

Checking concepts. . . Questions Test 1 -16