1 Cells and Organisation The microscope Diffusion Osmosis Active transport Animal cells Plant cells Organisation Cell division

2 The Microscope Mirror Stage Objective lens Eyepiece Focus

3 Diffusion Container filled at the bottom with bromine gas Your teacher may have shown you a container filled with bromine gas, at the bottom, in a fume cupboard. What would you observe after several minutes? What do we call this effect? The bromine gas spreads out to fill the whole container. The effect is known as diffusion. The bromine gas spreads out because the bromine molecules move from regions of high concentration to regions of low concentration.

4 Osmosis Water molecule Semi-permeable membrane Solute molecule High concentration of water molecules Low concentration of water molecules Water molecules diffuse through the semi-permeable membrane to even out the concentrations

5 Active Transport Water molecule Cell membrane Mineral ion High concentration of mineral ions Low concentration of mineral ions Minerals ions move against the concentration gradient as they move from the region of low concentration to the region of high concentration, this process requires energy

6 Plant Nucleus Nucleus Root tip packing cells x200

7 Animal Cells Cell membrane Cytoplasm Nucleus Mitochondria It should be noted that some animal cells do have a small food vacuole

8 Animal Cell Parts Cell membraneCytoplasm Nucleus Mitochondria Where chemical reactions occur controlled by enzymes, a jelly-like substance that is granular in nature Controls the cell, contains the genetic information, in the form of chromosomes, for cell replication Organelles that are found in the cytoplasm of animal cells (and plant cells) that produce energy from food Controls what enters and leaves the cell, it also gives the cell shape and support

9 Plant Cells Cell membrane Nucleus Cell wall Cytoplasm Vacuole Chloroplast

10 Plant Cell Parts Cell membraneCytoplasm Nucleus Cell wall Where chemical reactions occur, a jelly-like substance that is granular in nature Controls the cell, contains the genetic information, in the form of chromosomes, for cell replication Made of cellulose, helps to support the plant Controls what enters and leaves the cell, it also gives the cell shape and support Vacuole Contains cell sap, consisting of water and mineral salts Chloroplast Organelle that absorbs light energy to convert carbon dioxide and water into glucose

11 Cells Cells are the building blocks of life

12 Tissue Cells of the same type working together are known as tissue

13 Several different types of tissue working together to do a specific job are called an organ Organ

14 Organ System Several different organs working together to do a specific job are called an organ system

15 Organism An organism has several organ systems all working together to fulfil the seven life processes

16 Cell Division The type of cell division whereby cells divide and the two daughter cells have both a full set of chromosomes is known as mitosis.

17 Cell Division How do we grow? It is through a process known as cell division. Some cells, known as stem cells, have the ability to ‘become’ any specialised cell in an organism. When a stem cell becomes a specialised cell it loses its ability to undergo cell division. The process of cell division begins with the nucleus dividing into two. Each of these two daughter nuclei has an identical copy of the genetic information held within the parent nucleus. The cell membrane then divides in between the two daughter nuclei to form the two daughter cells.

18 Cell Division Stem cell Cell that will specialise Specialised cell Cell that will specialise Stem cell Specialised cell

19 Where Does Mitosis Occur? Mitosis occurs throughout plants and animals… Red blood cells are replicated in the bone marrow of bones such as the femur Root hair cells are replicated at the tips of roots

20 Exercise 1: Label the Instrument Light 4. ______ 3. ____________ 1. _________ 2. _______ Stage Objective lens Eyepiece Focus What is the name of this optical instrument? __________ Microscope

21 Exercise 2: Link the Boxes Cell membrane Nucleus Cytoplasm Controls what enters and leaves the cell, it also gives the cell shape and support Controls the cell, contains the genetic information, in the form of chromosomes, for cell replication Where chemical reactions occur controlled by enzymes, a jelly-like substance that is granular in nature Mitochondria Organelles that are found in the cytoplasm of animal cells (and plant cells) that produce energy from food

22 Exercise 3: Link the Boxes Cellulose Vacuole Cytoplasm Contains cell sap, consisting of water and mineral salts Organelle that absorbs light energy to convert carbon dioxide and water into glucose Made of cellulose, helps to support the plant

23 Exercise 4: Link the Boxes Diffusion Osmosis Active transport When water molecules move across a semi-permeable membrane from regions of high concentration to regions of low concentration When mineral ions move against the concentration gradient to enter and leave cells When gases and liquids spread out from regions of high concentration to regions of low concentration

24 Exercise 5: Short Questions 1.By what process does carbon dioxide gas enter a leaf through the stoma? 2.By what process does water enter a root hair cell from soil? 3.By what process do mineral salts enter root hair cells from soil? 4. By what process is glucose absorbed in the small intestine? 5. By what process does oxygen gas leave a leaf through the stoma? Diffusion Osmosis Active transport Diffusion

25 Exercise 6: Label the Diagram 2. _____________ 6. _________ 3. ________ 5. ___________ 1. ________ 4. ___________ Cell membrane Cell wall Vacuole Nucleus Cytoplasm Chloroplast

26 Exercise 7: Label the Diagram 2. _____________ 4. _________ 1. __________ 3. _____________ Mitochondria Cytoplasm Nucleus Cell membrane

27 Exercise 8: Animal Cells 1.What is the function of the organelle mitochondria? 2.Where is the genetic information found in a cell? 3.What do we call the jelly-like substance found in cells where most of the chemical reactions? 4. What is the function of the cell membrane? 5. What do we call the process of cell division where each of the daughter nuclei have a full set of genetic information? To release energy from food by respiration The nucleus The cytoplasm To control what substances enter and leave the cell Mitosis

28 Exercise 9: Plant Cells 1.What is the cell wall made from? 2.Which organelles contain the green substance chlorophyll? 3.Where is cell-sap found? 4. What is the function of the cell wall? 5. Give two examples of plant cells that do not contain chloroplasts. Cellulose Chloroplasts In the vacuole To provide support for the plant Epidermis cells (not guard cells) and root hair cells