Structure and Function of Plant and Animal Cells

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1 Science 14 Unit C: From Life to Lifestyle Chapter 8 Structure and Function of Plant and Animal Cells WORKBOOK Name:

8.1 A Closer Look pp. 158-164 Read pp. 158-159 Before the invention of microscope technology, scientific studies were rudimentary. Much of the work was based on trial and error.

and focus it on one spot, much like a magnifying glass o Originally able to view objects 30 times their actual size (Figure 8.1 p. 158) o saw beasties (bacteria) when magnified 200 times (Figure 8.

2 8.1 A Closer Look pp Read pp Before the invention of microscope technology, scientific studies were rudimentary. Much of the work was based on trial and error. The development of microscopes allowed scientists to see organisms that were previously invisible to the naked eye o Early microscopes were pieces of curved glass (convex lens) that could bend light and focus it on one spot, much like a magnifying glass o Originally able to view objects 30 times their actual size (Figure 8.1 p. 158) o saw beasties (bacteria) when magnified 200 times (Figure 8.3 p. 158) Modern compound microscopes have a stronger magnification than earlier devices and use light to illuminate objects being viewed. (Figure 8.5 p. 160) o magnifies objects 400 to 1000 times their actual size There are two types of electron microscopes that magnify more than times by relying on a beam of electrons rather than light o Object or specimen must be dead and covered in chemicals to observe using a transmission electron microscope (TEM) o living organisms are examined with a scanning electron microscope (SEM) where electrons pass over the specimen to produce a 3D image o see microscopic images on Figure 8.4 p

3 Contrast and Staining o Scientists learned that staining cells improved the contrast between internal cell parts. o Unstained cells are virtually colorless with little contrast between parts. o Manipulating the light source (diaphragm) allows you to alter the contrast of different structures in a cell. Properly Handling a Microscope o Be Careful!! o Carry it with 2 HANDS: one on the arm and the other on the base o Clean only with a soft cloth/tissue o Make sure it s on a flat surface o Don t bump it Using a Microscope o Start on the lowest magnification and use the course adjustment knob to focus. o Never use the coarse adjustment knob on high magnification you ll break the slide!! o Increase the magnification and only use the fine adjustment to focus on medium and high power. What scientists learned from their observations, and the questions they continued to ask about cells, have led to many technological advances that depend on knowledge from microscopy. The development of the microscope was a great boost for science. It allowed scientists who studied cells (referred to as cytologists) to observe details in plant and animal cells. These observations allowed them to develop greater understanding of the living world. Such advances include: o blood work to identify disease mechanisms o urine analyses to detect various substances (Example: sugar) that are indicators of disease (Example: diabetes) o the development of hybrid plants that have defenses against certain plant diseases and parasites o genetic developments, such as cloning 2

4 Discuss Figure 8.5 p. 160 Use the following diagram to label the parts of a compound microscope. hand lens curved glass for magnifying dissecting scopes microscope consisting of two eye pieces, a low power lens, and a medium power lens 3

5 Calculating Magnification Practice BLM 8-3 p. 163 Eyepiece magnification multiplied by magnification of the objective lens indicates the total magnification of an object under a microscope. Total Magnification = Ocular Lens x Objective Lens Example: Magnification of eyepiece: 5X Magnification of objective lens: 4X Total magnification: 5 x 4 = 20X Complete the following chart for practice. Use the information to determine the magnification of the specimens you are observing. Eyepiece Objective Lens Show Your Calculations Total Magnification (a) 5X 4X 5 x 4 = 20 20X (b) 5X (c) 5X (d) 10X (e) 10X (f) 10X (g) 20X (h) 20X (i) 20X 10X 40X 4X 10X 40X 4X 10X 40X 4

6 Microscope Word Challenge BLM Clues 1. equipment used to examine specimens at 100X or more 2. often used to study the internal organs of lab specimens 3. improved by two Canadians named Prebus and Hillier 4. a magnifying device used in most schools 5. earliest form of the microscope The letters in the boxes spell the name of a piece of magnifying equipment. What is it? Piece of magnifying equipment: Discuss CYU p. 164 #1-3 5

unit of life; the building block of all living organisms from the Latin word cella, meaning small room Tissue cells combined to perform a specific task or function Organ two or more tissues combined

7 Organization of Life (cell hierarchy) 8.2 Cell Theory pp Atom smallest unit of matter for both living and non living Molecules atoms grouped together form molecules Organelle part of a cell that carries out a specific function or role Cell smallest unit of life; the building block of all living organisms from the Latin word cella, meaning small room Tissue cells combined to perform a specific task or function Organ two or more tissues combined work together to do a specialized role System any group of organs working together to perform a specialized role Organism any living thing that carries out all 7 activities necessary to survive Cell Theory accepted explanation supported by repeated experimental results 1. Cells are responsible for function and structure in all organisms. 2. All living things are made up of cells. 3. All cells reproduce from other living things. i.e. cells are the smallest unit of life and come from other cells Bacteria and amoebas are made of one cell Humans are multi-cellular organisms Discuss CYU p. 165 #1-4 6

8 Word Scramble BLM 8-12 Unscramble the letters to discover these key terms from your study of cell theory. Use the definitions as clues to help you along. Definition Scrambled Word Answer a) when life processes are present, an organism is called this V I G L I N b) tissues combined to perform a specialized role G R O A N c) activities necessary in order to survive F I L E S P E C S O R E S d) part of a cell that carries out a particular function or role L E G L A N O R E e) cells combined to perform a specific task or function S U T I E S f) the smallest unit of life L C E L g) life processes are not present in this kind of object h) an explanation supported by repeated experimental results G I N V I N L O N H E R T O Y i) made up of organs working together M E S S Y T j) may consist of only one cell, or many cells S N A R G I O M 7

9 8.3 Plant & Animal Cell Structures pp A) Cell Membrane separates inner cell from surrounding environment semi-permeable (allows some materials in and keeps harmful materials out) B) Cytoplasm jellylike fluid holds organelles in place Animal C) Nucleus brain or control centre directs overall cell activity contains DNA D) Vacuole stores food, water, and waste materials looks like an empty sac E) Endoplasmic Reticulum (ER) transports food, water, and waste materials F) Mitochondrion powerhouse releases energy in the cell uses oxygen and digested food for energy Organelles G) Golgi Apparatus holds waste products until cell removes it packages and transports proteins specialized part of the ER H) Cell Wall (only in plant cells) protection and strength for cell. non-living. I.) Chloroplast (only in plant cells) contains chlorophyll (green color) helps collect sunlight for photosynthesis. Plant Discuss CYU p. 173 #1-4 8

Parts of the Cell BLM 8-13 Complete the chart by placing the missing information in the correct box. Identify whether you were using the plant or animal cell, and which letter identifies the part.

10 Parts of the Cell BLM 8-13 Complete the chart by placing the missing information in the correct box. Identify whether you were using the plant or animal cell, and which letter identifies the part. Use the list of cell parts to label the diagrams below. Cell Part Diagram Letter Function cytoplasm chloroplast mitochondrion Golgi Apparatus vacuole outer covering of a plant cell outer covering of an animal cell transportation system inside the cell control centre of the cell Plant Animal 9

11 Read pp Discuss CYU p. 175 #1-4 Organelle Crossword BLM 8-17 Across 1. semi-permeable; separates contents of cell from surrounding environment 4. collects sunlight; found only in plants 5. stores food, water, and waste 7. the powerhouse ; releases energy in cell Down 1. jelly-like substance 2. transports materials; known by initials 3. non-living; provides protection and strength 6. the control centre 10

12 Word Search BLM 8-18 Complete the word search puzzle by finding the 23 key terms listed below. Circle the words as you find them. Hint: The words may be hidden in any direction, but they will always be in a straight line. microscope organelle theory vacuole compound microscope living organism ER electron microscope non-living life processes cell membrane hand lens tissue nucleus cell wall dissecting scope organ cytoplasm chloroplast cell system mitochondrion 11

13 Chapter 8 Review Questions 1. Who played a leading role in the development of the microscope? (8.1) 2. Sketch a microscope. Label its parts. (8.1) 3. State the cell theory. (8.2) 4. List the life processes of all living things. (8.2) 5. Use a chart to show the difference between living and non-living things. (8.2) 6. Identify the parts of an animal cell. (8.3) 7. Identify the parts of a plant cell that are not part of an animal cell. (8.3) 8. What two parts of the cell handle transportation of materials? (8.3) 9. How are the functions of a cell similar to the functions of a city? (8.4) 12

14 Complete Chapter 8 Review Questions p. 176 #1-8 Please record your answers below or on an attached sheet of loose leaf. 13

Microscope History Robert Hooke

1 Microscope History Robert Hooke First described cells in 1665. He viewed thin slices of cork and compared the boxy partitions he observed to the cells (small rooms) in a monastery. (1635 1702) 2 Microscope