Year 7 Science 7B1: Microscopes, Cells and Plant Reproduction PPA Challenge

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1 Year 7 Science 7B1: Microscopes, Cells and Plant Reproduction PPA Challenge Name: Form:

2 Task Sheet 1 (Bronze Challenge): What parts does a microscope have? Use the words in the boxes below to label the parts of the microscope.

3 Task Sheet 2 (Bronze Challenge): How are plant and animal cells different? Animal Cell Plant Cell Key: = cell membrane = cell wall = cytoplasm = vacuole = nucleus = chloroplast Choose six colours; one for each part of the cell (organelle). Use these colours to colour code the parts of the cells above and the key. Complete the table below. Cell organelles that are found in plant AND animal cells Cell organelles that are ONLY found in plant cells

4 Task Sheet 3 (Bronze Challenge): What do the organelles of a cell do? Match the names of the cell organelles to their function (job). nucleus This surrounds the cell and controls what goes in and out. cell membrane This is liquid. It is where the chemical reactions take place. cytoplasm This controls everything that happens in the cell. cell wall This is green and absorbs sunlight to help plant cells make food. vacuole This is a tough layer that helps to support the cell. chloroplast This is a liquid and is only found in plant cells.

5 Task Sheet 4 (Bronze Challenge): The Structure of a Flower 1. Use words from the box to label the parts of the flower. 2. Colour the female parts of the flower one colour and the male parts of the flower another colour. Make sure you colour in the key to show which is which. Key: = female parts of the flower = male parts of the flower Words: petal sepal stamen stigma style anther filament nectary ovule ovary carpel

6 Task Sheet 5 (Bronze Challenge): Specialised Cells Link the image of the specialised cell to its name and function. sperm cell Absorbs light which the plant uses to make food. ovum (egg) cell Absorbs water and mineral ions from the soil. root hair cell Fertilises an egg cell. palisade cell Carries oxygen to the cells that need it. cilia cell Joins with a sperm cell and provides food for the new cell which forms, red blood cell Have tiny hairs that help to sweep mucus and particles out of the respiratory system.

7 Task Sheet 6 (Silver Challenge): Euglena Plant or Animal Cell? You are going to use the evidence to decide whether the single cell organism Euglena is a plant cell, an animal cell, both or neither. Read the statements below and decide whether each one is evidence for Euglena being a plant cell, an animal cell, both or neither write each statement into the appropriate column in the table on the next page. Make a decision as to which category Euglena best fits into and write an argument to justify your decision using the suggested sentence starters. Don t forget to write in full sentences, use persuasive language and punctuation. Evidence: Euglena has two outer layers. Euglena contains cytoplasm. There are more than two classification groups. Euglena confused early scientists. Euglena contains chloroplasts. Euglena can change its shape. Euglena has a nucleus. Euglena live in ponds and puddles. Euglena is a single cell. Euglena can swim through water. Euglena can absorb food from its surroundings. Euglena can make its own food. Euglena is normally green. Euglena has a vacuole. A vacuole controls the amount of liquid in a cell. Chloroplasts enable a cell to photosynthesise. Euglena is light sensitive. Euglena is temperature sensitive. The nucleus contains DNA and controls the cell activities.

8 Evidence that suggests Euglena is a plant cell Evidence that suggests Euglena is an animal cell Evidence that suggests Euglena is either a plant or an animal cell Evidence that suggests Euglena is neither a plant nor an animal cell

9 I think that Euglena is. The evidence to support my decision is The evidence to refute my decision is However, I think the evidence to support my decision is stronger because In conclusion,

10 Task Sheet 7 (Silver Challenge): Investigating Pollen Tube Growth Katie and Roisin decided to find out what effect the concentration of sugar solution would have on the length that pollen tubes grow to. Their results are shown in the table below. Concentration of sugar solution / % Average length of pollen tube / mm Use the data in the table to draw a line graph of average length of pollen tube (yaxis) against concentration of sugar solution (x-axis) on the graph paper on the next page. Remember to use pencil and ruler, label both axes with a quantity and a unit and draw a line of best fit through the plotted points. 2. At which concentration did the pollen tubes grow best? 3. Katie and Roisin s teacher said that these results were not enough to say which concentration of sugar produced the most growth. What should Katie and Roisin do to be certain of their conclusion? 4. What do you think the average length of the pollen tube would be if the sugar solution had a concentration of 45%?

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12 Task Sheet 8 (Gold Challenge): The Journey of a Seed You are going to write a short story about the journey of a seed. You need to imagine that you are the seed and describe the journey you took. Use the information below to help you plan and write your story on the lined paper following these instructions. If you run out of space you can use extra lined paper. You can also type it on the computer if you prefer. Choose one of the following seeds to write about: Top Tips: sycamore seed burdock seed pond iris seeds 1. You should write in the first person; so use words such as I, me, mine and my. 2. Write in the past tense as you are describing a journey that happened in the past. 3. Try to include as much detail as possible. 4. Use as many key words from the glossary at the back of the booklet as possible. The sections you should use are flowers, plant reproduction and seed dispersal. You must include descriptions of: How you (the seed) were produced so describe what happened during pollination and fertilisation in the flower that made you. Consider What is pollination? Describe it. Was the flower pollinated by an insect, the wind or by some other means? If it was insect pollinated, what was the insect? What attracted it to the flower - colour, scent or something else? If it was wind pollinated, how was the flower adapted for this? What is fertilisation? Describe it. How and where did you (the seed) form? How you (the seed) were dispersed to a different location. How you (the seed) developed into a new plant.

13 Some suggested sentence starters (you can use some, all or none of these it is up to you!): I was created when a bee landed on a flower. The bee was searching for nectar and was attracted to the flower because When the bee landed on the flower pollen grains from the anthers got stuck to Next the bee moved to another flower and After pollination a pollen tube grew from the pollen down the During fertilisation the Once I had become a seed Finally I Connectives you might like to use: firstly secondly next then also in addition while gradually consequently simultaneously finally My Story: I am a seed. I am going to tell you about my journey.

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15 Task Sheet 9 (Gold Challenge): How Big? When we use a microscope the object we are looking at is magnified. The magnification depends on which lens we use. The eyepiece lens has a magnification of x10. So if we just looked through this lens the object would look ten times bigger. There are three objective lenses; these also magnify the object. So the object is first magnified by the objective lens and then by the eyepiece lens. The total magnification is the two multiplied together. 1. Complete the table below to show the total magnification. Magnification of eyepiece lens Magnification of objective lens Total magnification x 10 x 4 x 40 x 10 x 10 x 10 x Complete the gaps in the table below. Use a calculator to help you. Object being observed under the microscope Real size / mm Magnification of eyepiece lens Magnification of objective lens Total magnification Size object appears / mm Amoeba 0.74 x 10 x 4 x Bacteria x 10 x 40 Human hair (thickness) 0.02 x 10 x 10 Red blood cell x 10 x 100 White blood cell x 10 x 400 Fruit fly x 10 x Sperm cell x 10 x Egg cell x 10 x 40 4

16 Microscopes and Cells: Key Words Glossary microscope magnification nucleus cell membrane cytoplasm chloroplast vacuole cell wall mitochondria respiration cell tissue organ organ system Specialised Cells: sperm cell ovum (egg) cell nerve cell palisade cell root hair cell

17 cilia cell epithelial cell red blood cell Human Organ Systems: excretory system circulatory system digestive system respiratory system reproductive system nervous system endocrine system skeletal system muscle system Unicellular Organisms: unicellular amoeba euglena flagellum Diffusion: diffusion concentration particles

18 Flowers: petal sepal stamen anther filament carpel stigma ovary Plant Reproduction: pollination fertilisation seed germination tropism external stimuli Seed dispersal: seed dispersal wind dispersal animal dispersal water dispersal explosive

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