LIFE SCIENCES GRADE 10 CAPS STRUCTURED CLEAR PRACTICAL

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LIFE SCIENCES GRADE 10 CAPS: STRUCTURED, CLEAR, PRACTICAL HELPING TEACHERS UNLOCK THE POWER OF

LIFE SCIENCES GRADE 10 CAPS: STRUCTURED, CLEAR, PRACTICAL HELPING TEACHERS UNLOCK THE POWER OF NCS KNOWLEDGE AREA: Life at the molecular, cellular and tissue level Topic 1: Chemistry of life Cell structure and function: the roles of organelles

CAPS SPECIFIC AIMS 1. Knowing Life Sciences 2. Investigating Phenomena in Life Sciences 3.

CAPS SPECIFIC AIMS 1. Knowing Life Sciences 2. Investigating Phenomena in Life Sciences 3. Appreciating and Understanding the History, Importance and Applications of Life Sciences in Society

SPECIFIC SKILLS � Access information � Select key ideas Recall information Describe knowledge of

SPECIFIC SKILLS � Access information � Select key ideas Recall information Describe knowledge of NS Build a conceptual framework Organise or reorganise knowledge Write summaries Develop flow charts and mind maps Recognise patterns and trends � � � � Apply knowledge in new contexts Use knowledge in a new way Analyse information/data Critically evaluate scientific information Recognise relationships between existing knowledge and new ideas Identify assumptions Categorise information

SUMMARY OF PRESENTATION Organization Differences in size, shape and structure of cells. Structure of

SUMMARY OF PRESENTATION Organization Differences in size, shape and structure of cells. Structure of each cell component

ORGANIZATION � Cells are made up of many of the organic compounds we discussed

ORGANIZATION � Cells are made up of many of the organic compounds we discussed earlier. � They are made up of proteins, lipids and carbohydrates. � There are small structures within the cell that carry out various functions. � These structures are called organelles. � Cells are organized in such a way that they form very efficient and complex organisms.

ORGANIZATION CELLS These are the basic unit of life TISSUES Are a group of

ORGANIZATION CELLS These are the basic unit of life TISSUES Are a group of similar cells that work together to carry a common function. Different tissues form organs SYSTEMS Various organs work together to carry out a single function. All these organs together form a system ORGANISM Different systems function together to form an organism

SOMETHING TO DO: � Can 1. 2. 3. 4. you give some examples of:

SOMETHING TO DO: � Can 1. 2. 3. 4. you give some examples of: Cells Tissues Organs systems

SOLUTION: 1. 2. 3. 4. Plant cell and animal cell Parenchyma, xylem and muscle,

SOLUTION: 1. 2. 3. 4. Plant cell and animal cell Parenchyma, xylem and muscle, bone Leaf, flower, root and heart, brain and lung. Transport, digestive and reproductive system

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS � Different cells have different sizes.

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS � Different cells have different sizes. � Some cells are microscopic while others are macroscopic. � Microscopic cells are so small they cannot be seen with the naked eye. � They can only be viewed under the microscope. � Some examples of microscopic cells are plant cell, animal cell and bacteria. � Macroscopic cells are large enough to be seen with the naked eye. This means that you do not need the microscope. � Examples of macroscopic cells are the human egg which is as big as the full stop at the end of this sentence and the ostrich egg cell.

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS � Since cells are so small

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS � Since cells are so small the normal units of measurement are too large to use. � Therefore different units of measurement are used. � These units are smaller than centimeters and even millimeters. � The units of measurement used here are microns and � In nanometers. order for us to understand how small these units really are we compare it to a unit of measurement that you are familiar with, that is millimeters

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS RELATIONSHIP BETWEEN MICRONS AND NANOMETERS �A

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS RELATIONSHIP BETWEEN MICRONS AND NANOMETERS �A micron is represent by the symbol μm. � A nanometer is represented by the symbol nm. � The relationship between the micron and nanometer is shown below… a. 1 mm = 1000 μm b. 1 μm = 1000 nm � This information can be used to convert from nm/ μm to mm or even cm. � Some examples of the sizes of cells are a. The human egg is 0. 1 mm or 100 μm b. Red blood cell is 0. 007 mm

SOMETHING FOR YOU TO DO Express the size of the red blood cell in

SOMETHING FOR YOU TO DO Express the size of the red blood cell in microns. Show all working.

SOLUTION � 0. 007 mm = 0. 007 X 1000 = 7 μm Since

SOLUTION � 0. 007 mm = 0. 007 X 1000 = 7 μm Since 1 000 μm = 1 mm So to convert form mm to μm we multiply by 1000 and To convert from μm to mm we divide by 1000.

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS- SHAPES AND STRUCTURES � Cells have

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS- SHAPES AND STRUCTURES � Cells have many different shapes and structures. � For example some cells have a regular shape while others have an irregular shape. � A regular shape means that it as a shape that can be named, circle, square or rectangle etc. � An irregular shape is one that cannot be named and maybe changing, like the amoeba. � The shape of the cells has to do with the function it performs.

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS- SHAPES AND STRUCTURES � The table

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS- SHAPES AND STRUCTURES � The table below shows the relationship between cell shape and function. Cell Shape/size Reason for shape/size Human nerve cells elongated So that they are able to transmit impulses over great distances Spongy mesophyll cells Irregular shape This shape means that the cells cannot fit closely togetherefore large spaces are formed between the cells. These spaces are used for transport of gases and water.

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS- SHAPES AND STRUCTURES Cell Shape/size Reason

DIFFERENCE IN SIZE, SHAPE AND STRUCTURE OF CELLS- SHAPES AND STRUCTURES Cell Shape/size Reason for shape/size Red blood cell Biconcave discs This shape allows the cell to fit in the blood vessels and therefore allows for easy movement. Parenchyma cells Irregular Allows for large spaces between the cells that allow for the movement of substances from one part of the organ to another.

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE PLANT CELL �A generalized plant cell

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE PLANT CELL �A generalized plant cell is made up of a cell wall and the protoplasm. � The protoplasm is all the living part of the cell. � The cell wall surrounds the protoplasm. � The protoplasm is made up of the cytoplasm and the nucleus as shown in the diagram alongside.

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE PLANT CELL The cytoplasm is surrounded

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE PLANT CELL The cytoplasm is surrounded by the cell membrane. � The cell membrane may also be called the plasma membrane. � The cytoplasm contains many small structures. � These structures maybe called organelles or cytoplasmic inclusions. � Examples of the organelles in the plant cells are the mitochondria; plastids; ribosomes; vacuole; dictyosomes and the endoplasmic reticulum (ER). � Examples of cytoplasmic inclusions are pigments and lipids � In the plant cell the nucleus has a nuclear membrane, nuclearplasm, nucleoli and the chromatin network. �

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE PLANT CELL

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE PLANT CELL

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE ANIMAL CELL � � � In

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE ANIMAL CELL � � � In the animal there is no cell wall. Therefore there is only a protoplasm. The protoplasm is made up of the cytoplasm and nucleus. The cytoplasm contains the following organelles cell membrane, mitochondria, ER, dictyosomes and ribosome. The nucleus is the same as the one in the plant cell. The most important thing about the nucleus is that it is bound by the nuclear membrane.

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE ANIMAL CELL

THE RELATIONSHIP AMONG THE MAIN COMPONENTS OF THE ANIMAL CELL

PLANT AND ANIMAL CELL

PLANT AND ANIMAL CELL

SOMETHING FOR YOU TO DO � Look at the previous slide and tabulate 4

SOMETHING FOR YOU TO DO � Look at the previous slide and tabulate 4 visible differences between plant and animal cells.

SOLUTION � Differences between plant and animal cell(√) Plant cell Animal Cell (√) 1.

SOLUTION � Differences between plant and animal cell(√) Plant cell Animal Cell (√) 1. Outermost boundary is the cell wall 1. Outermost boundary is the cell membrane (√) 2. Has a regular shape 2. Has an irregular shape (√) 3. Chloroplast present 3. No chloroplast present (√) 4. Has a single large vacuole 5. Small vacuole. (√)

STRUCTURE OF EACH CELL COMPONENT CELL WALL � The cell wall is made up

STRUCTURE OF EACH CELL COMPONENT CELL WALL � The cell wall is made up of � These 3 parts. three parts are the: a. b. c. The middle lamella Primary wall Secondary wall

STRUCTURE OF EACH CELL COMPONENT CELL WALL-STRUCTURE � The middle lamella is a thin

STRUCTURE OF EACH CELL COMPONENT CELL WALL-STRUCTURE � The middle lamella is a thin membranous layer. � It is found between two plant cells. � The primary cell wall is found on the inside of the middle lamella. � The primary cell wall is made up of cellulose. � All mature tissue contain the primary cell wall. � The secondary cell wall develops on the inside of the primary cell wall. � The secondary cell wall is found in only in some specialized cells. � It can be made up of lignin or suberin.

STRUCTURE OF EACH CELL COMPONENT CELL WALLFUNCTIONS � Since it is found on the

STRUCTURE OF EACH CELL COMPONENT CELL WALLFUNCTIONS � Since it is found on the outside one of its most important is protection. It provides all the contents of the cell with protection. � It encloses cell. � Gives the cell shape. � Provides a framework and support for the cell. � The middle lamella binds the cells together. � The cell wall is permeable, so it is involved in transport, allow most substances to pass through.

THE PROTOPLASM � The protoplasm is all the living parts of the cell. �

THE PROTOPLASM � The protoplasm is all the living parts of the cell. � It is made up of the cytoplasm and the nucleus. � Also includes all the organelles and inclusions found in the cytoplasm. � Parts of the protoplasm is shown in the diagram alongside.

THE CYTOPLASM � The cytoplasm includes the cell membrane, the sol, the gel, inclusions

THE CYTOPLASM � The cytoplasm includes the cell membrane, the sol, the gel, inclusions and organelles. � The organelles are membrane bound structures that have specific functions. � Some of these organelles are plastids, mitochondria and ER. � We shall look at some of the structures of the cytoplasm.

THE CELL MEMBRANE � The cell membrane may also be called the plasma membrane

THE CELL MEMBRANE � The cell membrane may also be called the plasma membrane or the plasma lemma. � It is the outermost boundary of the cytoplasm. � No one has seen the cell membrane, because it is so thin that it cannot be seen even with the most powerful electron microscope. � Scientist however have studied the cell membrane, studying its behavior under various conditions and used these result to come up with theories or models on the structure of the cell membrane.

FLUID MOSAIC MODEL � One such model or theory is called the fluid mosaic

FLUID MOSAIC MODEL � One such model or theory is called the fluid mosaic model. � This model was put forward in 1972 by Singer and Nicholson. � According to this model the cell membrane is made up of lipids and proteins.

FLUID MOSAIC MODEL These lipids and proteins are arranged in the following way: There

FLUID MOSAIC MODEL These lipids and proteins are arranged in the following way: There are two layers of phospholipids that are stuck together. The protein molecules are arranged throughout these two layers. Some the protein molecules go right through the two layers , while some only go partly through the two layers. There are small openings found at regular intervals. These openings are called pores and they are about 1 nm in size. They allow only some substances to pass through.

CELL MEMBRANE- FUNCTION � In an animal cell the cell membrane functions to protect

CELL MEMBRANE- FUNCTION � In an animal cell the cell membrane functions to protect the contents of the cell because it is the outermost layer. � The most important function of the cell membrane is that it controls the entry and exit of certain substances only. � Unlike the cell wall it does not allow all substances to enter or leave the cytoplasm. It selects the substances that are allowed to enter or leave the cell membrane. Therefore the cell membrane can also be called the selectively permeable membrane.

MOVEMENT ACROSS MEMBRANES � Substances need to enter and leave the cell in order

MOVEMENT ACROSS MEMBRANES � Substances need to enter and leave the cell in order for the cell to carry out its functions. � For example waste substances like carbon dioxide need to leave the cell and glucose need to enter the cell for cellular respiration. � These substances need to move across the membranes of the cell in order for them to enter and leave a cell. � There 3 ways in which substances can enter and leave the cell. � These 3 ways are: 1. Diffusion 2. Osmosis 3. Active transport.

DIFFUSION is the movement of liquid or gas particles from a region of high

DIFFUSION is the movement of liquid or gas particles from a region of high concentration to a region of low concentration until equilibrium is reached. � These particles are able to move because of their kinetic energy. � Therefore the rate of diffusion can be altered by increasing or decreasing the kinetic energy of these particles. � Diffusion

IMPORTANCE OF DIFFUSION TO PLANT AND ANIMAL CELLS. � Gases enter and leave the

IMPORTANCE OF DIFFUSION TO PLANT AND ANIMAL CELLS. � Gases enter and leave the cells through diffusion. Oxygen enters the cells and alveoli of the lung by diffusion and carbon dioxide leaves the cells and the alveoli of the lung by diffusion. � Glucose and amino acids leaves the intestines and enters the cells by diffusion.

OSMOSIS � Osmosis is the movement of a liquid from a region of high

OSMOSIS � Osmosis is the movement of a liquid from a region of high concentration to a region of low concentration across a differentially permeable membrane until equilibrium is reached. � Another way of say this is the movement of a liquid from a dilute to a concentrated solution across a differentially permeable membrane until equilibrium has been reached. � Water usually moves into and out of a cell by osmosis. � When water enters a cell by osmosis then endosmosis has occurred. � When water leaves a cell by osmosis then exosmosis has occurred.

IMPORTANCE OF OSMOSIS TO PLANTS AND ANIMALS � Water enters and leaves plant and

IMPORTANCE OF OSMOSIS TO PLANTS AND ANIMALS � Water enters and leaves plant and animal cells by osmosis. � This water carries useful substances such as nutrients with it as it enters the cell. � It also carries waste substances out with , it as it leaves a cell.

ACTIVE TRANSPORT � Substances usually move or are moved from a region of high

ACTIVE TRANSPORT � Substances usually move or are moved from a region of high concentration to a region of low concentration. � Sometimes it is necessary to move in the opposite direction, that is from a low to high concentration. � When this occurs we say that they are moving or being moved or absorbed against a concentration gradient. � This type of transport is called active transport. � This transport needs energy in order for it to occur.

CYTOPLASM ORGANELLES AND INCLUSIONS MITOCHONDRIA � Mitochondria are found in the cytoplasm of both

CYTOPLASM ORGANELLES AND INCLUSIONS MITOCHONDRIA � Mitochondria are found in the cytoplasm of both plant and animal cells. � Their numbers vary in the different cells. � The more active the cell the larger the number of mitochondria present. � Therefore a muscle cell will have many more mitochondria than say for example the skin cell or the amoeba.

MITOCHONDRIA STRUCTURE � The mitochondrion has a cigar or elongated shape. � They can

MITOCHONDRIA STRUCTURE � The mitochondrion has a cigar or elongated shape. � They can also be spherical or threadlike in shape. � It is surrounded by a double membrane. � The double membrane is made up of an outer membrane and an inner membrane.

MITOCHONDRIA STRUCTURE � The inner membrane is folded into finger like structures. � These

MITOCHONDRIA STRUCTURE � The inner membrane is folded into finger like structures. � These structures are called the cristae. � The inner membrane encloses a ground substance.

MITOCHONDRIA STRUCTURE � The ground substance is called the matrix. � The DNA, RNA

MITOCHONDRIA STRUCTURE � The ground substance is called the matrix. � The DNA, RNA and the ribosomes are found in the matrix. � The diagram below is of the mitochondria. � This diagram is called a micrograph. � Try to identify the different parts of the mitochondria in the micrograph.

MITOCHONDRIA FUNCTION � The mitochondria is the site of cellular respiration. � Cellular respiration

MITOCHONDRIA FUNCTION � The mitochondria is the site of cellular respiration. � Cellular respiration is the process during which energy is released. � Since they are responsible for the release of energy they are often called the powerhouse of the cell.

PLASTIDS � Plastids are found in plant cells only. � They are small in

PLASTIDS � Plastids are found in plant cells only. � They are small in size. � They may be disc-shaped, ovoid or irregularly shaped organelles. � There are plastids. 3 types of

PLASTIDS-CHLOROPLAST � These a) � � � 1. 2. are the: Chloroplast These are

PLASTIDS-CHLOROPLAST � These a) � � � 1. 2. are the: Chloroplast These are green organelles. They are green in colour because they contain the pigment chlorophyll. Chlorophyll has two important functions: Gives parts of the plant their green colour. It traps sunlight for photosynthesis.

PLASTIDS CHROMOPLAST b) Chromoplast � These are plastid have an irregular shape They maybe

PLASTIDS CHROMOPLAST b) Chromoplast � These are plastid have an irregular shape They maybe coloured red, orange or yellow. The pigments carotenes and xanthophylls are responsible for this colour. They give colour to fruit, flowers and leaves � � �

PLASTIDS LEUCOPLAST c) Leucoplast � These are colourless plastids. These plastids are found in

PLASTIDS LEUCOPLAST c) Leucoplast � These are colourless plastids. These plastids are found in the parts of the plant not exposed to sunlight. Their function is to store foods in different forms e. g. starch, lipids and proteins. � �

PLASTID STRUCTURE OF CHLOROPLAST � The chloroplast is a disc shaped organelle. � It

PLASTID STRUCTURE OF CHLOROPLAST � The chloroplast is a disc shaped organelle. � It is surrounded by a double membrane, an inner and outer membrane � A ground substance is found within the double membrane.

PLASTID STRUCTURE OF CHLOROPLAST � The ground substance is called the stroma. � Found

PLASTID STRUCTURE OF CHLOROPLAST � The ground substance is called the stroma. � Found in the stroma are stacks of coin likes structures. � Each stack is called the granum

PLASTID STRUCTURE OF CHLOROPLAST � Each granum is made up of many coin like

PLASTID STRUCTURE OF CHLOROPLAST � Each granum is made up of many coin like structures. � Each coin like structure is called the thylakoid. � Each thylakoid is made up of membranes called lamella.

PLASTID STRUCTURE OF CHLOROPLAST � The chlorophyll is found within each thylakoid. � One

PLASTID STRUCTURE OF CHLOROPLAST � The chlorophyll is found within each thylakoid. � One granum is joined to another by the intergranal lamella. � Also found in the stroma are starch granules and ribosome. Intergranal lamella

PLASTID STRUCTURE OF CHLOROPLAST � The starch granules are used to store starch �

PLASTID STRUCTURE OF CHLOROPLAST � The starch granules are used to store starch � The ribosomes are used during the manufacture of enzymes that are used for the process of photosynthesis.

MICROGRAPHS CHLOROPLAST � Carefully study the micrograph below.

MICROGRAPHS CHLOROPLAST � Carefully study the micrograph below.

MICROGRAPHS CHLOROPLAST

MICROGRAPHS CHLOROPLAST

SOMETHING FOR YOU TO DO � Study the micrograph below and answer the questions

SOMETHING FOR YOU TO DO � Study the micrograph below and answer the questions that follow: 1. 2. 3. Identify the organelle shown. Give two visible reasons for you answer. Make a labelled drawing of the above micrograph.

SOLUTION 1. 2. 3. Chloroplast Presence of starch granule and grana Your teacher will

SOLUTION 1. 2. 3. Chloroplast Presence of starch granule and grana Your teacher will draw the diagram on the board for you.

ENDOPLASMIC RETICULUM ER � These are a system of tubes that are enclosed by

ENDOPLASMIC RETICULUM ER � These are a system of tubes that are enclosed by membranes.

ENDOPLASMIC RETICULUM ER � They are found in both plant and animal cells. �

ENDOPLASMIC RETICULUM ER � They are found in both plant and animal cells. � They seem to be continuous with the cell membranes and nuclear membrane. � There are two types of ER.

ENDOPLASMIC RETICULUM ER � These � The are the smooth ER and the rough

ENDOPLASMIC RETICULUM ER � These � The are the smooth ER and the rough ER has ribosomes attached to it to give it the rough appearance, while the smooth ER has no ribosomes.

GOLGI APPARATUS � The Golgi apparatus is also called the dictyosomes. � It was

GOLGI APPARATUS � The Golgi apparatus is also called the dictyosomes. � It was first identified in 1898 in the brain cells by Camillo Golgi. � They occur in both plant and animal cells. � They occur in larger numbers and are bigger in size in secretory cells. � They are well developed in the goblet cells in the alimentary canal. � Therefore it is thought that they have a secretory function.

GOLGI APPARATUS

GOLGI APPARATUS

RIBOSOME � These are small, grain-like substances. � They are found in the cytoplasm,

RIBOSOME � These are small, grain-like substances. � They are found in the cytoplasm, or on the ER, in the plastids and even in the mitochondria. � Each ribosome is made up of two parts, protein and ribosomal RNA (r. RNA). � The ribosome is the site of protein synthesis. � This means that it is the place on which proteins are made.

VACUOLES � The vacuoles are fluid filled organelles � Each vacuole is surrounded by

VACUOLES � The vacuoles are fluid filled organelles � Each vacuole is surrounded by a membrane. � This membrane is called the tonoplast. � The tonoplast encloses a liquid. � This liquid is called the cell sap. � The cell sap is a solution of water and dissolved substances. � Some of these dissolved substances are salts, sugar and protein.

VACUOLES � Vacuoles also have a type of pigment called anthocyanins. � These anthocyanin

VACUOLES � Vacuoles also have a type of pigment called anthocyanins. � These anthocyanin are responsible for the blue, violet, dark red or scarlet colour of certain parts of the plant. � The cell sap also creates pressure within the cell. � This pressure is called turgor pressure. � Turgor pressure maintains the shape of the cell. � Vacuoles are found in both plant and animal cells.

LYSOSOMES � These are more or less round vesicles. � They are mostly found

LYSOSOMES � These are more or less round vesicles. � They are mostly found in animal cells. � They are surrounded by a single membrane. � The lysosome contain digestive enzymes. � Lysosmes fuse with the food vacuole and the digestive enzymes are released into the food vacuole. � These enzymes digest the food. � This type of digestion is called intracellular digestion.

INTRACELLULAR AND INTERCELLULAR �Intra means within � Therefore intracellular means within the cell. �Inter

INTRACELLULAR AND INTERCELLULAR �Intra means within � Therefore intracellular means within the cell. �Inter means between. � Therefore intercellular means between the cells. Can you explain what intracellular digestion means?

ANSWER Intracellular digestion is when digestion occurs inside the cell.

ANSWER Intracellular digestion is when digestion occurs inside the cell.

CENTROSOMES � The centrosome is an area of the cell. � They contain cylindrical

CENTROSOMES � The centrosome is an area of the cell. � They contain cylindrical structures called the centrioles as shown below:

CENTROSOMES � The centrioles are made up of small tubular bodies or microtubules. �

CENTROSOMES � The centrioles are made up of small tubular bodies or microtubules. � The exact function is unknown. � However during cell division in animal cells, the centrioles move towards the ends of the cells. � These ends are called the poles. � At the poles centrioles are responsible forming the spindle fibers.

NUCLEUS-LOCATION � The nucleus is a large, darkly stained body found in both plant

NUCLEUS-LOCATION � The nucleus is a large, darkly stained body found in both plant and animal cells. � In animal cells they are found in the centre of the cell in plant cells they are not found in the centre because of the large vacuole.

NUCLEUS STRUCTURE � The nucleus is bound by a double membrane called the nuclear

NUCLEUS STRUCTURE � The nucleus is bound by a double membrane called the nuclear membrane. � The nuclear has pores on it. These pores are called nuclear pores. These pores allow substances to enter and leave the nucleus. � Within the nuclear membrane there is a ground substance called the nucleoplasm.

NUCLEUS STRUCTURE important structures are embedded in the nucleoplasm. � These two substances are

NUCLEUS STRUCTURE important structures are embedded in the nucleoplasm. � These two substances are the nucleolus and chromatin network. � The chromatin network is a tangled mass of thread like structures. � These thread-like structures are called chromosomes � Each chromosome is made up of two parts. � Two � These two parts are the chromatids and centromere.

NUCLEUS STRUCTURE �A single chromosome is made up of two chromatids that are held

NUCLEUS STRUCTURE �A single chromosome is made up of two chromatids that are held together by a centromere. � The nucleolus is a darkly stained body found at the centre of the nucleoplasm.

NUCLEUS FUNCTION � The 1. 2. 3. functions of the nucleus are as follows:

NUCLEUS FUNCTION � The 1. 2. 3. functions of the nucleus are as follows: It controls all activities of the cell. It controls the production of enzymes. It is responsible for the transmission of hereditary characteristics from parent to offspring.

TERMINOLOGY � Cells: These are the basic unit of life � Tissues: Are a

TERMINOLOGY � Cells: These are the basic unit of life � Tissues: Are a group of similar cells that work together to carry a common function � Microscopic cells: are so small they cannot be seen with the naked eye. � Macroscopic cells: are large enough to be seen with the naked eye. � Protoplasm: is all the living part of the cell.

TERMINOLOGY � Diffusion is the movement of liquid or gas particles from a region

TERMINOLOGY � Diffusion is the movement of liquid or gas particles from a region of high concentration to a region of low concentration until equilibrium is reached � Osmosis is the movement of a liquid from a region of high concentration to a region of low concentration across a differentially permeable membrane until equilibrium is reached. � Endosmosis is when water enters a cell by osmosis. � Exosmosis is when water leaves a cell by osmosis.

TERMINOLOGY � Active transport is when a substance is moved or absorbed against a

TERMINOLOGY � Active transport is when a substance is moved or absorbed against a concentration gradient and it requires energy. � Cellular respiration is the process during which energy is released. � Intra means within � Intracellular means within the cell. � Inter means between. � Intercellular means between the cells. � Intracellular digestion is digestion that occurs within the cell.

The basic unit of life is a … A. B. C. D. Cell Tissue

The basic unit of life is a … A. B. C. D. Cell Tissue Organ System

Similar cells that work together to perform a common function is the… A. B.

Similar cells that work together to perform a common function is the… A. B. C. D. Cell Tissue Organ System

Cells that are too small to be seen with the naked eye are called…

Cells that are too small to be seen with the naked eye are called… A. B. C. D. Macroscopic Microscopic Nanometic None of the above.

The protoplasm… A. is all the living part of the cell. B. includes the

The protoplasm… A. is all the living part of the cell. B. includes the cytoplasm and nucleus. C. A only D. Both A and B.

The function of the cell wall is… A. B. C. D. To enclose the

The function of the cell wall is… A. B. C. D. To enclose the cell Control all activities of the cell. Give the plant its green colour To trap sunlight

The cell membrane is made up of … A. B. C. D. Fatty acids

The cell membrane is made up of … A. B. C. D. Fatty acids and glycerol Lipids and carbohydrates Proteins and lipids

The middle lamella is a part of the… A. B. C. D. Cell membrane

The middle lamella is a part of the… A. B. C. D. Cell membrane Cell wall Nuclear membrane Tonoplast

The cell component that is not involved in osmosis is… A. Chloroplast B. Mitochondrion

The cell component that is not involved in osmosis is… A. Chloroplast B. Mitochondrion C. Cell membrane D. Cell wall

The semi-permeable membrane that encloses the animal cell is… A. B. C. D. Cell

The semi-permeable membrane that encloses the animal cell is… A. B. C. D. Cell wall Cell membrane Tonoplast Nuclear membrane

The micrograph is of… A. B. C. D. Chloroplast Mitochondria ER Golgi apparatus

The micrograph is of… A. B. C. D. Chloroplast Mitochondria ER Golgi apparatus

The micrograph is of the… A. Chloroplast B. Mitochondria C. ER D. Golgi apparatus

The micrograph is of the… A. Chloroplast B. Mitochondria C. ER D. Golgi apparatus

The micrograph shows the … A. Chloroplast B. Mitochondria C. ER D. Golgi apparatus

The micrograph shows the … A. Chloroplast B. Mitochondria C. ER D. Golgi apparatus

The organelle shown is the… A. Chloroplast B. Mitochondria C. ER D. Golgi apparatus

The organelle shown is the… A. Chloroplast B. Mitochondria C. ER D. Golgi apparatus

Small disc shaped, pigment containing organelles found in plant cells only are… A. B.

Small disc shaped, pigment containing organelles found in plant cells only are… A. B. C. D. Plastids Mitochondria ER Golgi apparatus

The powerhouse of the cell is the… A. B. C. D. Chloroplast Mitochondria ER

The powerhouse of the cell is the… A. B. C. D. Chloroplast Mitochondria ER Golgi apparatus

The darkly stained body in a cell is the… A. B. C. D. Chloroplast

The darkly stained body in a cell is the… A. B. C. D. Chloroplast Mitochondria Nucleus Golgi apparatus

The projections on the inner membrane of the mitochondria is the… A. B. C.

The projections on the inner membrane of the mitochondria is the… A. B. C. D. Golgi apparatus Leucoplast Cristae Grana

The membranous vesicles which have a secretory in function is… A. Golgi apparatus B.

The membranous vesicles which have a secretory in function is… A. Golgi apparatus B. Leucoplast C. Cristae D. Grana

The colourless plastid… A. B. C. D. Golgi apparatus Leucoplast Cristae Grana

The colourless plastid… A. B. C. D. Golgi apparatus Leucoplast Cristae Grana

The following are characteristics of plant cells only: A. Many small vacuoles, chloroplasts, no

The following are characteristics of plant cells only: A. Many small vacuoles, chloroplasts, no cell wall. B. No vacuoles, cell membrane outer most membrane, no plastids C. Cell wall and cell membrane, large central vacuole, plastids present. D. Cell membrane only, large central vacuole, plastids present

SOLUTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. A B C

SOLUTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. A B C D A D B A

11. 12. 13. 14. 15. 16. 17. 18. 19. 20. D C B A

11. 12. 13. 14. 15. 16. 17. 18. 19. 20. D C B A B C C A B C