Unit 9 Photosynthesis in Green Plants

Science Interactive LTD Multimedia CD-ROM for PC is a collection of 38 units totalling over 1150 PowerPoint slides matched to current single and double Science GCSE syllabuses. Each unit covers a wide range of different delivery and learning styles, offering an exciting way to involve your pupils during lessons or revision sessions. All styles of teaching and learning are supported through use of high quality images, graphics, challenging exercises and questions. Units can be used in the classroom via an interactive whiteboard , data projector or used during individual study via a PC or school network. Full users’ licence is available under our ‘ comprehensive package ’ or lessons can be purchased separately. Science Interactive LTD. PO BOX 50764 LONDON NW6 9AT email: sales@science-interactive.co.uk web: www:science-interactive.co.uk GCSE SCIENCE OCR EDEXCEL AQA Science Interactive LTD Copyright 2005 Unit 19: The Transitional Metals Unit 18: Metals and their Properties Unit 17: The Alkali Metals Unit 16: The Periodic Table and its Elements Unit 15: Genetic Engineering Unit 14: Evolution and Human Impact Unit 13: Inheritance and Selection Unit 12: Mitosis and Meiosis Unit 11: Flow of Energy and Elements through the Environment Unit 10: Water Transport in Plants Unit 9: Photosynthesis in Green Plants Unit 8: Drugs and Bad Body Maintenance Unit 7: Hormones and the Endocrine System Unit 6: Human Homeostasis Unit 5: Nervous System and the Senses Unit 4: The Respiratory System Unit 3: Healthy Body and Immunity Unit 2: The Circulatory System Unit 1: The Digestive System Unit 38: Cells, Tissue, Organs and Organs systems Unit 37: Natural Forces Unit 36: Sound and Hearing Unit 35: The Alkaline Earth Metals Unit 34: The Earth and Plate Tectonics Unit 33: Earth and Space Unit 32: Newton's Forces and the Effects of Forces Unit 31: Radioactivity Unit 30: Light and the Electromagnetic Spectrum Unit 29: Electricity Unit 28: Generating Electricity and its Domestic Use Unit 27: Energy Unit 26: Rates of Reaction Unit 25: The Noble Gases, their Properties and Uses Unit 24: The Halogens, their Uses and Compounds Unit 23: Ionic and Covalent Compounds Unit 22: Elements, Molecules and Compounds Unit 21: Rock Cycle Unit 20: Crude Oil and its Products

Unit 9

Photosynthesis in Green Plants

The anatomy and cell parts of the common plant cell.

The role of the chloroplast and mitochondria during photosynthesis and respiration.

The role of the leaf and the palisade cell during photosynthesis.

That the substrates for photosynthesis are water and carbon dioxide.

That the products of photosynthesis are glucose and oxygen.

That light energy is essential for photosynthesis to occur.

That the overall rate of photosynthesis is determined by limiting factors including carbon dioxide, light intensity, light colour and temperature.

That plants use glucose to make other molecules.

That plants can respond to stimuli like light, gravity and moisture.

Leaf, Tissue, Organ, Cell, Palisade, Photosynthesis, Substrates, Water, Carbon dioxide, Products, Glucose, Oxygen, Light, Energy, Intensity, Limiting, Factors, Light, Temperature, Colour, Rate, Tropism & Stimuli. Unit 9: Photosynthesis in Green Plants web: www.science-interactive.co.uk email: sales@science-interactive.co.uk Science Interactive LTD PO BOX 50764 LONDON NW6 9AT Click mouse to begin Science Interactive LTD Copyright 2005 Understand: Keywords:

Levels of organisation in plants In plants, as in animals, similar cells performing similar f__________ are organised into tissues. Leaf palisade tissue consists of identical palisade cells functioning together to enable photosynthesis to occur. Other tissues found in green l________ also support photosynthesis. A leaf is an organ made up of many different tissues. Different organs work together as part of the entire plant organism. There are four distinct organs in a typical plant: The root system, the stem system, the leaf system and the reproductive system. Name the function of each of the four organ systems found in green plants ? Cells, tissues, organs and organ systems in plants: Science Interactive LTD Copyright 2005 Word bank: functions leaves Organs are a collection of tissues like the leaf. Many separate organs build an organ system. List 3 organs in the plant ? Organs The are four organ systems that support life in plants. All perform specific roles. Which of these systems does not support photosynthesis ? Tissues like the palisade layer or stomata tissue are a collection of cells working together to perform specific tasks in the plant. Cells are highly specialised and are designed to do their job within the plant. List 3 specialised cells found in green plants ? Notes Diagram Cells Tissues Organism

Plant leaf system A number of cells and tissues within the plant leaf play a role during photosynthesis, whereby water and carbon dioxide combine during photosynthesis to form g_______ and o_________. Palisade cells containing chloroplast are the main site of glucose production. Xylem tissue supplies water from the root and phloem tissue transports glucose made during photosynthesis around the plant. Gaseous exchange during photosynthesis and respiration is controlled by the stomata cells . Why are the stomata cells found only on the underside of the leaf ? Plant leaf system: A B C D E Science Interactive LTD Copyright 2005 Word bank: glucose oxygen The leaf is a collection of tissues: A: Upper epidermis B: Palisade layer C: Spongy mesophyll D: Lower epidermis E: Stomata Plant leaf The leaf system is a collection of leaves that work together producing glucose and oxygen from water and carbon dioxide using the energy from the sun during daylight hours. The xylem tissue transports water and minerals like nitrates from the root system to the leaf system via the plant stem. Phloem tubes transport sugary sap all around the plant. Stomata found on the underside of the plant leaf allows gaseous exchange and water transpiration. They open during the day and remain closed during the night. Notes Diagram Stomata cells Xylem tissue Leaf system

Specialised cells in plants Like animals, plants have many different s____________ cells performing different functions. Green plants have many examples of specialised cells that are designed for functions like photosynthesis, growth, reproduction, taking in w______ and minerals from the soil. The leaf palisade cell is a good example of a specialised cell in plants. It is well designed for photosynthesis, for example it contains many chloroplasts organelles, rich in chlorophyll. Where is the palisade tissue located in the plant ? Specialised cells: Science Interactive LTD Copyright 2005 Word bank: specialised water The stomata cells controls the exchange of CO 2 and oxygen during photosynthesis. They close during the night. At what time during the day does CO 2 enter the leaf ? Stomata cell Pollen cells, normally transferred to the female carpel by bees and other insects carry genetic information to create a new plant when it fuses with the female ovule. The root hair cell has a large surface area to volume ratio, so that it can absorb water and minerals from the soil . Name two of these mineral salts found dissolved in water ? Green leaves contain many palisade cells which are rich in chloroplasts that enable photosynthesis to occur. Why do root cells not have these cell parts ? Notes Diagram Palisade cell Root hair cell Pollen cell

The common plant cell Plant cells, like animals cells are made from many cell parts or organelles, each with a specific function. The common plant cell has some similarities and some differences to animal cells. This reflects differences in the way plants and animals feed and support themselves. The most important cell part is green c____________ containing chlorophyll which allows photosynthesis to occur. Common plant cell: Science Interactive LTD Copyright 2005 Word bank: chloroplast Lysosome Mitochondria Chloroplast Cell wall Vacuole Membrane Cytoplasm Nucleus Cell part _______________________ ? _______________________ ? _______________________ ? _______________________ ? _______________________ ? _______________________ ? _______________________ ? Control cells activities and contains DNA Function (complete)

Mitochondria and chloroplast organelles If you view plant and animals cells under a microscope, you can see tiny dots in the cytoplasm. These are the mitochondria. Cellular r____________ occurs in the mitochondria, releasing energy from glucose molecules. Plants also have green c____________ containing chlorophyll where water and carbon dioxide are combined to form glucose and o_________ during photosynthesis. Why do muscle cells contain more mitochondria than skin cells ? Mitochondria and chloroplast: Membrane Membrane Matrix Matrix Science Interactive LTD Copyright 2005 Word bank: respiration chloroplast oxygen Plant only Animal and plant Animal or plant 6H 2 O + 6CO 2 _____ + _____ C 6 H 12 O 6 + 6O 2 6H 2 O + 6CO 2 Equation To produce glucose using CO 2 and water. All green plants have these organelles. To respire glucose with oxygen providing cell energy. All living cells have these organelles. Function in the cell Diagram Mitochondria Chloroplast

Plants as producers one Plants are called producers because they produce all the World’s biomass via a process called photosynthesis. Plants use energy from the s_____ to combine carbon dioxide and w________ to form g__________ and oxygen. This reaction produces millions of tonnes of living matter that nourishes all other living organisms in the animal kingdom. The oxygen that plants release into the atmosphere is used in cellular r_____________ by all living organisms. How can we determine the biomass of a plant ? Plants as producers: Science Interactive LTD Copyright 2005 Word bank: sun water glucose respiration Plant yield: (kg per hectare) 14000 10000 6000 2000 <1000 C 6 H 12 O 6 6O 2 6CO 2 6H 2 O Plant cells Chloroplast Energy Glucose Plants only use a small fraction of the sunlight energy, they receive every year. Despite this, sugarcane produces up to 200 tonnes of glucose per year per hectare. The most productive areas are the equatorial regions that receive the most sunlight energy. Plant yield Green chlorophyll contained in palisade chloroplasts are able to use light energy to enable carbon dioxide and water to combine to form glucose and oxygen. Notes Diagram Photosynthesis in action

Plants as producers two The glucose produced during photosynthesis in green plants is used to make plant c____________, lipids and proteins. Every year over 70,000,000 kJ of sunlight energy falls on every metre squared of land. Plants only use about 90,000 kJ/m 2 / year of l_______ energy during photosynthesis, however they produce over 132 billion tonnes per annum of biomass. Overall plant yields depend on a number of factors including light availability, soil quality, rainfall levels and competition. How could you determine the yields of different crops over time ? Plant yield and biomass: Science Interactive LTD Copyright 2005 Word bank: carbohydrates light Rice, rich in carbo-hydrates can produce a yield of up to 3000 kg per acre Rice Wheat, rich in carbo-hydrates and sugars can produce a yield of up to 2500 kg per acre. Corn, rich in proteins and carbohydrates can produce a yield of up to 5500 kg per acre. Sugarcane, rich in glucose can produce a yield of up to 9000 kg per acre. Notes Diagram Crop Sugarcane Corn Wheat

Plants as producers three Plants are extremely efficient at transforming the energy carried by light to chemical energy trapped in glucose molecules, which are produced during p_____________. Their efficiency is about 80%, far higher than typical values for herbivores and carnivores. Only a small fraction of the c__________ energy they produce in the form of glucose is lost through respiration or waste. How could you determine the amount of glucose that is used during cellular respiration in plants ? Plants using light energy : 1 1 2 2 3 3 Biomass Waste Respiration Biomass: Energy contained in the tissues of the plant (available for the next level.) Waste: Energy contained in the waste materials found in leaves. Respiration: Energy used in cellular respiration by all plant cells. 8,000 kJ 1,500 kJ 500 kJ Light energy 10,000kJ Science Interactive LTD Copyright 2005 Word bank: photosynthesis chemical Only a very small fraction of energy is used for respiration or lost as waste. Plants are almost 80% efficient as producers. The transfer of energy from the sun’s rays to the glucose found in plant leaves is achieved during photosynthesis. Plants are highly adapted and efficient at transforming light energy to chemical energy. Over 132 billions tonnes of plant biomass is produced globally every year. Notes Diagram Plants use of light energy Process

Plants as producers four Plant leaves contain many palisade cells containing green c___________. Palisade cells use e______ from sunlight during photosynthesis to make g________ and oxygen. This palisade cell layer is found near to the surface of the leaf. Here it can absorb all the sunlight that falls on the leaf’s surface. How could you design an experiment to show that light is an essential factor for photosynthesis ? Plants using light energy: A B C D E F G Science Interactive LTD Copyright 2005 Word bank: chloroplasts energy glucose Only a very small fraction of energy is used for respiration or lost as waste. Plants are almost 80% efficient as producers. The transfer of energy from the sun’s rays to the glucose found in plant leaves is achieved during photosynthesis. Plants are highly adapted and efficient at transforming light energy to chemical energy. Over 132 billions tonnes of plant biomass is produced globally every year. Notes Diagram Anatomy of the plant leaf A: Upper epidermis B: Palisade layer C: Spongy mesophyll D: Lower epidermis E: Stomata F: Xylem G: Phloem Give a function of the leaf tissue. Say how each part helps photosynthesis ? Process

Plants as producers five Every tissue found in green leaves, supports the production of glucose during photosynthesis. Palisade cells containing green c___________ have enzymes which use light energy to combine water and carbon dioxide forming glucose and oxygen. The xylem transports w______ from the root. Phloem tubes transport glucose to the rest of the plant. Stomata cells allows carbon dioxide from the atmosphere and promote transpiration. The spongy mesophyll allows carbon dioxide to diffuse quickly to the palisade cells. Why are the palisade cells filled with chloroplast found in the upper part of the leaf ? Plants leaf structure and anatomy: Science Interactive LTD Copyright 2005 Word bank: chloroplast water Cuticle Upper epidermis Palisade layer Spongy mesophyll Lower epidermis Stomata Guard cells Xylem Phloem Give a function for each tissue found in green leaves. Say how each part helps photosynthesis ? Parts of the leaf

Photosynthesis, the process whereby l______ energy is used by palisade cells found in green leaves to combine carbon dioxide and water to produce glucose and oxygen. This is the equation for the whole process.

From the equation we can see there are three requirements:

Light

Chlorophyll

Substrates: Carbon dioxide and water

Requirements for photosynthesis:

Photosynthesis and its equation one Carbon dioxide + Water Glucose + Oxygen Light and chlorophyll Science Interactive LTD Copyright 2005 Word bank: light Carbon dioxide Water Carbon dioxide, absorbed by the leaf and water absorbed by the root hair cells are essential substrates that are used during photosynthesis making glucose and oxygen. Green chlorophyll found in the leaf palisade layers uses light energy to form glucose and oxygen. It contains a very complicated series of enzymes that act as catalysts. Light is used to provide the energy required during photosynthesis to combine water and carbon dioxide producing glucose and oxygen. Notes Carbon dioxide and water Diagram Light Chlorophyll

Photosynthesis and its equation two From the equation for photosynthesis, we can determine the raw materials required during photosynthesis. Glucose production in green leaves will only occur if w_______ and carbon dioxide are supplied to the chloroplasts inside leaf palisade cells. 6CO 2 + 6H 2 0 C 6 H 12 O 6 + 6O 2 Carbon dioxide water light and chlorophyll Glucose Oxygen Raw materials and photosynthetic products: 6 molecules of CO 2 6 molecules of H 2 O 1 molecule of glucose 6 molecules of O 2 Science Interactive LTD Copyright 2005 Word bank: water Glucose produced during photosynthesis is transported by the phloem to all parts of the plant. Glucose Oxygen is taken out through the leaf during daylight hours and released into the atmosphere. Water is taken from the soil by the root hair cells, through the xylem and into the leaf space. Carbon dioxide is taken in during day light hours through the leaf stomata cells from the atmosphere. Notes Diagram Oxygen Water Carbon dioxide Substrate

Reactions that take in energy from their surroundings in the form of heat or light are called endothermic reactions . Although these types of reactions are not as common as exothermic reactions, there are several examples. An important example of an endothermic reaction is photosynthesis , whereby light e_________ is used to combine water and carbon dioxide to form glucose and oxygen. Energy changes during photosynthesis: Products Substrates C 6 H 12 O 6 6O 2 6H 2 O 6CO 2 Activation energy Net energy taken in during reaction Photosynthesis and its equation three Science Interactive LTD Copyright 2005 Word bank: energy Progress of reaction Potential energy O 2 H 2 O CO 2 C 6 H 12 O 6 In this reaction H 2 O and CO 2 substrates are combined in the plant leaf cells using light energy to produce glucose (C 6 H 12 O 6 ) and O 2 . Key Photosynthesis in green plants

Sunlight, carbon dioxide, water and g______ chlorophyll are all essential for photosynthesis to take place inside a green leaf. Proving that these are essential, however requires experimentation. A series of experiments were carried out and are summarised in the table below. In brief, plants with no access over 48 hours to sunlight, chlorophyll or carbon dioxide were tested for starch in their l________. For each experiment, complete the results and give an explanation ? Factors required for photosynthesis: Complete Complete Photosynthesis and its equation four Science Interactive LTD Copyright 2005 Word bank: green leaves _______________________________________________________________________? _______________________________________________________________________ ? Starch is shown by a blue - black colour when in contact with iodine. What does this experiment prove ? Explanation 3: No carbon dioxide Results Show leaf after testing with iodine solution. Diagram 1: No light 2: No chlorophyll

Limiting factors for photosynthesis From the equation for photosynthesis, we can also determine the limiting factors affecting the r_______ of glucose production in green leaves. The rate of photosynthesis speeds up as light intensity increases, but only up to a point. The overall rate may also be limited by the concentration of carbon dioxide, the temperature or even the colour of light. Factors that can affect the rate of photosynthesis are called limiting factors . Limiting factors: 6CO 2 + 6H 2 0 C 6 H 12 O 6 + 6O 2 Carbon dioxide water light and chlorophyll Glucose Oxygen Science Interactive LTD Copyright 2005 Word bank: rate Red and blue light are absorbed by plants, whereas green light is reflected and not used during photosynthesis. The greater the concentration of CO 2 the greater the rate of photosynthesis in green plants. The higher the temperature the more often H 2 O and CO 2 molecules collide into each other. Light from the sun is used to provide the energy required to combine H 2 O and CO 2 during photosynthesis. Notes CO 2 Concentration Equation Diagram Light intensity Temperature Colour of light

Limiting factors light intensity one During photosynthesis, molecules of water and carbon dioxide collide, form new chemical bonds producing glucose and oxygen. The energy required to form these new bonds in glucose is provided by light energy. The rate of p____________ increases when the amount of light energy increases, but only up to a point. Other factors, like carbon dioxide concentration and temperature also affect the overall rate of photosynthesis. These are called limiting f__________. The factor in shortest supply will always be the limiting factor . Affect of light intensity on the rate of photosynthesis : 0.1m 0.2m 0.3m Science Interactive LTD Copyright 2005 Word bank: photosynthesis factors 1: Plot a graph of distance (m) versus rate of oxygen production ? 2: Is there a relationship between light intensity and rate of photosynthesis ? 3: What is this relationship ? 4: What are the other limiting factors in this experiment ? 5: How could you test out you answer for question 4 ? 6: Why is important to control the temperature of the water ? 45 134 269 300 42 123 245 270 37 109 210 240 32 88 189 210 27 76 157 180 22 65 134 150 17 45 109 120 12 32 67 90 7 22 45 60 3 11 23 30 Oxygen bubbles at 0.3m Oxygen bubbles at 0.2m Oxygen bubbles at 0.1m Time (seconds) Diagram 0.3m 0.2m 0.1m Distance (m) 3 2 1 Experiment

Closed Open Closed Limiting factors light intensity two During the night, no photosynthesis takes place, just plant respiration. At dusk and dawn when the light intensity is low, the rate of respiration and photosynthesis are roughly the same. During the day, when there is greatest l______ energy, there is a net production of glucose and oxygen. The stomata cells, found on the underside of the leaf open during daylight hours when photosynthesis occurs and partially close during the night. Stomata are opened and closed by the guard cells changing shape. These guard cells contain chloroplasts, which provide the energy for stomata opening and closing. Affect of light intensity on stomata opening and closing : Science Interactive LTD Copyright 2005 Word bank: light Notes Diagram

Limiting factors CO 2 concentration The rate of photosynthesis increases when the concentration of carbon dioxide increases, but only up to a point. Other factors, like l______ intensity and temperature also affect the overall rate of photosynthesis in green plants. These are called limiting factors. The factor in shortest supply will always be the limiting factor . Affect of CO 2 concentration on the rate of photosynthesis: 0.1% CO 2 0.25% CO 2 0.5% CO 2 0.1m 0.1m 0.1m Science Interactive LTD Copyright 2005 Word bank: light 1 :Plot a graph of CO 2 concentration (%) versus rate of oxygen production ? 2: Is there a relationship between CO 2 (%) concentration and the rate of photosynthesis ? 3: What is this relationship ? 4: What are the other limiting factors for this experiment ? Diagram 0.5% 0.25% 0.1% CO 2 (%) 3 2 1 Experiment 702 595 323 300 645 545 298 270 578 489 256 240 498 430 230 210 378 324 180 180 256 223 140 150 201 167 102 120 134 101 68 90 65 54 38 60 43 31 19 30 Oxygen bubbles at 0.5% CO 2 Oxygen bubbles at 0.25% CO 2 Oxygen bubbles at 0.1% CO 2 Time (seconds)

Limiting factors temperature 25 o C 35 o C 45 o C 0.1m 0.1m 0.1m The rate of photosynthesis in green plants increases when temperature is increased, but only up to a point, due to other limiting factors like carbon dioxide concentration and light intensity . This is because the two substrates; water and carbon dioxide have a higher kinetic energy, therefore colliding more often and with greater f_______ inside the palisade cell chloroplasts. Very high temperatures stop photosynthesis altogether. This is because, like other enzyme catalysed processes, plant enzymes are denatured when subjected to very high temperatures. Affect of temperature on the rate of photosynthesis: Science Interactive LTD Copyright 2005 Word bank: force 1: Plot a graph of temperature ( o C) versus rate of oxygen production ? 2: Is there a relationship between temperature and rate of photosynthesis ? 3: What is this relationship ? 4: What are the other limiting factors ? 5: Why, when the temperature was increased to 45 o C in expt 3, was the rate of photosynthesis very low ? Diagram 45 o C 35 o C 25 o C Temp ( o C) 3 2 1 Experiment 32 689 323 300 25 615 298 270 22 502 256 240 19 456 230 210 15 356 180 180 11 287 140 150 7 189 102 120 4 128 68 90 3 70 38 60 2 38 19 30 Oxygen bubbles at 45 o C Oxygen bubbles at 35 o C Oxygen bubbles at 25 o C Time (seconds)

Limiting factors colour of light The rate of photosynthesis can also be affected by the colour of light. This is because green chlorophyll absorbs r____ and b_____ light and reflects green. When green light is reflected, the light energy is not available to the chloroplasts during the formation of g__________ and oxygen from carbon dioxide and water. Why are many of the seaweeds found deep below the water’s surface red ? Affect of light colour on the rate of photosynthesis: Green Red Blue White Science Interactive LTD Copyright 2005 Word bank: red blue glucose 1: Plot a graph of colour of light versus rate of oxygen production ? 2: Is there a relationship between colour of light and rate of photosynthesis ? 3: What is this relationship ? 4: What are the other limiting factors ? 5: Why is the rate of photosynthesis not zero for green light ? 6: Show in a diagram using a green plant leaf, what colours are absorbed and reflected during photosynthesis ? 323 298 256 230 180 140 102 68 38 19 White light at 25 o C 42 35 30 24 19 16 12 10 6 4 Green light at 25 o C 134 159 300 123 140 270 99 130 240 89 120 210 60 100 180 48 67 150 35 49 120 24 34 90 11 20 60 5 10 30 Red light at 25 o C Blue light at 25 o C Time (seconds) Green 3 Diagram Red Blue White Colour of light 4 2 1 Expt.

Plant use of glucose general overview During photosynthesis in green plants, only glucose (C 6 H 12 O 6 ) is manufactured. This glucose is then used by green plants for a number of uses including respiration, fruit production, g________ and repair. Plants are able to take a simple molecule like glucose and manufacture all the other types of molecules, including enzymes, l________, proteins and carbohydrates. They really are food factories and essential to all other animal life. Why is the word producers a good term to use when describing plants ? Affect of light intensity on the rate of photosynthesis : Science Interactive LTD Copyright 2005 Word bank: growth lipids During the day there is a net production of glucose and oxygen by plants as the result of photosynthesis. This glucose is then used during respiration or assimilated and used in the manufacture all the other molecules like proteins, carbohydrates and lipids. Notes Diagram

Pollination is the transfer of pollen, the male sex cells from the a_________ of the stamen by b____ or insects to the surface of the female c_________. Once the pollen sex cells have landed on the female carpel, pollination has been achieved. Flowering plants contain both female and male reproductive organs and can either self or cross pollinate. Following fertilisation, where the ovule and pollen cell fuse, the seed begins to develop surrounded by the swollen ovule which forms the f_______. It is the function of the fruit to disperse the seed. What is this organ’s role in the plant life cycle ? Plant reproductive system: Plant use of glucose reproduction Science Interactive LTD Copyright 2005 Word bank: anther bees carpel fruit The stamen is the plant male reproductive organ which contains many millions of microscopic pollen cells. Male anther Flowering plants have both male and female reproductive organs. Plants can self or cross pollinate. The egg cells or ovules contain the maternal genes and are held in the ovule, part of the female carpel. Pollen, the male sex cells contain the paternal genes and are held on the anther which is part of the male stamen. Notes Diagram Pollen cells Female carpel Reproductive system

Plant use of glucose fruits and tubers It is the function of the fruit to disperse the seed. Fleshy fruits like apples, pears, oranges and tomatoes contain lots of sugar as a reward for a_________ and insects. These animals and insects, by eating fruit containing seeds, help spread the seeds prior to g_____________ during the following spring. Also roots tubers swollen with carbohydrates, like those found in carrots, turnips and potatoes act as a food reserve for new growth in the following spring. The sugar or carbohydrates contained in the fruit or root tubers is made during photosynthesis and is transported by the phloem tubes from the leaf. Plant fruits and tubers: Science Interactive LTD Copyright 2005 Word bank: animals germination Potatoes Fruits, root vegetables and nuts all contain sugar or carbohydrates made from sugar produced during photosynthesis. These plant products all contain stored chemical energy which animals then eat, digest and assimilated into their own bodies. Without plants, there would be no food chains and no oxygen, another product of photosynthesis. Notes Diagram Apples Oranges Carrots

Tropisms in plants one Plants can respond to environmental stimuli like light, gravity and water. Unlike humans and other animals, plants cannot move themselves because they lack a skeletal m________ system. Plants can, however grow towards or away from a light source. Plant shoots grow towards the light, whereas plant roots grow towards gravity and moisture. If you germinated a seed in space with zero gravity, what would the growth response of the root be like ? Plant reproductive system: Auxin accumulates on the dark side of the shoot causing cell elongation and the subsequent bending of the shoot towards the light source Science Interactive LTD Copyright 2005 Word bank: muscle In the picture above, the tree clearly grows towards the primary source of light. Plants respond to light by using a hormone called auxin. Auxin causes cell elongation and is broken down by sun light. The non-illuminated side therefore elongates bending the shoot towards the sunlight. If the sun is overhead, the shoot continues to grow in an upwards direction. Why do we germinate seeds in the dark ? Growing towards the light Response to light in plant shoots

Tropisms in plants two Plants must grow in one direction or another to respond to stimuli like light, moisture or even gravity. They can’t simply m_______ because thy don’t have a nervous or muscle system. The following experiments help us understand the role auxin plays in controlling a plant’s response. Look at the three different scenarios and predict where auxin is found and how this affects plant growth ? Plant reproductive system: Science Interactive LTD Copyright 2005 Word bank: move The bottom of the shoot is covered. The tip of the shoot where auxin is found is still able to respond to the light stimulus, by growing towards it. The tip of the shoot is covered with foil. Auxin is present on both sides and in equal amounts. The shoot continues to grow upwards. The shoot responds to the light by growing towards the light. Auxin is found on the dark side (right hand side) and causes cell elongation. Notes Diagram Scenario two Scenario three Scenario one

1: Define the following terms: Photosynthesis, Substrates, Products, Glucose, Oxygen, Limiting factors & Rate-limiting-factors. 2: Look at the diagram of the three types of leaf tissue. Complete the table. 3: Answer the following: a) How does water and carbon dioxide arrive at the palisade cell for photosynthesis. b) How is sugar transported around the plant. c) Sugar is also used by all plant cells during respiration to produce energy for life processes in the plant. Compare photosynthesis and respiration. d) During the day do plants respire. e) How could you prove your answers in part (c) by performing an experiment. Explain all the steps. f) Explain why the leaf cuticle is transparent. What other role does the cuticle play. Extension questions and homework Xylem tubes Palisade cells Stomata Science Interactive LTD Copyright 2005 How is it specialised Palisade cells Xylem Stomata Function the in the green leaf Tissue

4: Look at the information in the table below. It shows the diameter of the stomata cells over a 24hr period: a) Explain why the diameter changes over this 24hr period b) At midday the light intensity is strongest. How do the stomata cells react to this. c) At dawn and dusk, is the rate of respiration and photosynthesis the same. 5: a) Other than water and carbon dioxide, plants also need minerals (e.g. phosphates, nitrates and potassium) what are these minerals used for and how do the plants obtain them. b) Show how a specialised root hair cell takes in minerals like nitrates from the soil. c) Do the minerals given in part (a) give any energy value to the plant. d) Compare those minerals that plants require for healthy growth to the minerals and vitamins we require in our own diet. e) Somebody observed that wheat grows taller and gives a higher yield when the field is closer to a coal burning power station. Suggest a reason for this. f) Explain why grass doesn’t need cutting during the winter months when the average daily temperature is below 6 o C. 6: Complete the following: Plants produce ____________ and oxygen during photosynthesis. This all takes place in the chloroplast found in the _______________ cells. The active chemical in the chloroplast is called _____________. It is able to use light energy to form new chemical bonds between water and carbon dioxide. Science Interactive LTD Copyright 2005 0.01 0.10 0.20 0.25 0.40 0.40 0.25 0.15 0.1 0.01 Diameter (cm) 22.00 20.00 18.00 16.00 14.00 12.00 10.00 08.00 06.00 00.00 Time (hr)

7: a) Plants and crops need mineral salts for healthy growth. Give the name of three of these mineral salts. b) A farmer wants to increase his crop yield by using fertilisers. The able below shows how mass of crop produced from a field depends on the quantity of nitrogen used. (i) What is the maximum mass of crop that could be produced using nitrogen fertilisers. (ii) Explain why using 700kg/hectare of fertilisers actually decreases crop yield compared to your answer in part (i). (iii) Large amounts of fertilisers dissolve in water. When it rains fertilisers can accumulate in rivers and ponds. Explain why this is a problem. (iv) Some consumers prefer organically grown crops. State two advantages and disadvantages of eating organically grown crops. 8: a) Explain the difference between ‘peat culture’ and ‘nutrient film’ hydroponics. b) What are the benefits of intensive farming to the (i) farmer and (ii) consumer. c) What are the disadvantages of intensive farming to (i) the consumer (ii) biodiversity (iii) the environment. 9: Complete the following: Water passes into the root hair cell by ___________. Mineral salts like _____________ potassium and phosphate are taken up by active transport. A root hair cell has a ____________ surface area to help water and mineral salt uptake. Water is then transported through the ___________ tubes by capillary action to the leaf tissue. Palisade cells require water during photosynthesis to manufacture glucose. Water is lost through the leaves thorough the _____________. They are opened during the day and close at night when no p______________ takes place. Internet: Go to google.co.uk and find out about fertilizers and how they provide essential minerals for healthy plant growth. Look at how the fertilizers are rated (N:P:K value) and what role each mineral plays in healthy plant growth. Science Interactive LTD Copyright 2005 7.5 100 14 300 13 700 16 500 15.5 400 15 12 6 Crop yield (tonnes/hectare) 600 200 0 Amount of nitrogen (kg)