Cell Organisation and Microscopy PDF

.  Do Now ( 3 minutes) Write at least 10 keywords from last lesson. Learning Objectives:- Define the terms tissue, organ and organ systems, with examples. To understand the terms magnification and resolution and calculate magnification.  Success Criteria define and differe...

.  Do Now ( 3 minutes) Write at least 10 keywords from last lesson. Learning Objectives:- Define the terms tissue, organ and organ systems, with examples. To understand the terms magnification and resolution and calculate magnification.  Success Criteria define and differentiate between a tissue, organ, and organ system with clear examples. Understand how different tissues form organs and how organs function in an organ system. Can explain the concept of magnification and resolution. Accurately calculate magnification using the given formula. Levels of organisation I do activity cell tissue organ organ organism systems nerve cell nervous brain nervous Homo sapiens tissue system smallest largest A tissue is a group of cells of similar structure that perform a shared function Tissues found in the leaf Animal tissues: muscle tissue upper epidermal tissue palisade mesophyll tissue spongy mesophyll nervous tissue tissue lower epidermal tissue Cross-section of a leaf An organ is a structure made of a group of tissues working together to perform specific functions heart lungs liver stomach brain kidneys Plant organs include the stem and the leaves An organ system is a group of organs that coordinate to perform related functions lymphatic digestive reproductive skeletal endocrine system system system system system respiratory excretory muscular nervous circulatory system system system system system In plants the shoot is an organ system consisting of leaves and the stem Now write down everything you remember from the presentation Don’t refer to your text book straight away, see what information you have retained. Check the notes you have made by checking your book.  Microscopes and magnification LO : To understand the terms magnification and resolution and calculate magnification. STARTER: What are microscopes used for and how do they work? Key words: Microscope Eyepiece Stage Focus Resolution Magnification  Recap Each of the following sentences has at least one mistake in it. Rewrite each one, correcting the mistakes: A) The vacuole contains a substance called cytoplasm B) Animal cells have a cell wall, a nucleus and cytoplasm C) Chloroform is a green substance found in chloroplasts D) A cell is held together by a cell surface counterpane E) The cell wall is used for storage F) The cytoplasm controls the cell What do these objects have in common? Why do we use them?  Microscopes Microscopes are used to magnify an image (make it larger). When do you think the first microscope invented?  The early microscope In 1665, Robert Hooke used an early microscope to look at cork. He called what he saw ‘cells’. Why do you think he called them cells? How have microscopes have changed since then?  Light microscopes Light (or optical) microscopes are often used in biology. Light passes through the specimen (sample) and through a set of lenses which magnify the image. Parts of a microscope- We do activity A E B C F D G  Parts of a microscope Eyepiece Coarse Objective focus lens Stage Fine focus Slide Light  Some key terms Magnification is how many times larger an image is, than the real size of the object. Resolution is how detailed an image is - how well it can distinguish between two separate points. Same magnification, different resolutions. How do these images show magnification and resolution?  The electron microscope Invented in the 1930s. Instead of light, beams of electrons pass through a specimen. They have a much better magnification and resolution. What do you think could be seen using an electron microscope?  Onion Cell Light Microscope Electron Microscope Magnification up to 2000 times; Magnification up to Resolution 200 nm. 2,000,000 times; Resolution 0.1 nm. Question: Why can you only see the organelles of the onion cell by using an electron microscope?  Units kilometre metre centimet millimetr micrometr nanometre (km) (m) re (cm) e (mm) e (mm) (nm) x 1000m 1 x 0.01m x x x or 10 m 3 or 10- 0.001m 0.000,001 0.000,000,001 2 m or 10- m or 10-6m m or 10-9m 3 m  Units of length In biology length is expressed in metres, or fractions/ multiples of a metre. Multiple or fraction Symb Name of unit of a metre ol So …..... kilometre 10 3 km 1 km = 1000 m metre 1 m 1m = 100cm centimetre 10 -2 cm 1000 mm 1000,000 millmetre 10 -3 mm µm micrometre 10 -6 µm nanometre 10 -9 nm 1000,000,000 nm  Starting unit Convert to Calculation Example 1: How many nm is there in 2m? Kilometre (km) Metre (m) X 1000 Use the table to get the correct conversion factor. In this case we need to convert metres into nanometres. Metre (m) Kilometre (km) ÷ 1000 Ans: 2m x 1,000,000,000 = 2,000,000,000 nm Centimetre (cm) Metre (m) ÷ 100 Metre (m) Centimetre (cm) X 100 Example 2: How many m is there in 60m? Millimetre (mm) Metre (m) ÷ 1000 Use the table to get the correct conversion factor. Metre (m) Millimetre X 1000 In this case we need to convert micrometres into metres. (mm) Ans: 60m ÷ 1,000,000 Micrometre Metre (m) ÷ 1,000,000 = 0.00006m (mm) Metre (m) Micrometre X 1,000,000 (mm) Question: How many cm is there in 2.5m? Nanometre (nm) Metre (m) ÷ 1,000,000,000 Ans: 2.5m x 100 = 2500cm Metre (m) Nanometre X 1,000,000,000 (nm)  Calculating actual size You may need to calculate the actual size of an object Actual size Image size = Magnificatio n Task: Rearrange the equation to find… Remember: the 1. Image size = Actual size x units for actual Magnification Image size size and image 2. Magnification = size must be Actual size the same! L4+ I can calculate magnification with same units. WE DO ACTIVITY 20 ÷ 10 ÷ Easier – Same units of measurement 0.002 = 0.006 = x10,000 Object Image Size Actual size x1,666.67 300 ÷ Magnification 0.01 = E Coli 20mm 0.002mm x x30,000 Yeast Cell 10mm 0.006mm x Blood cell 300mm 0.01mm x 40 ÷ 0.5 Pollen Grain 40mm 0.5mm x = x80 6 ÷ 3.5 = Hair 6cm 3.5cm x1.7 x 15mm ÷ Difficult – Different units of 0.003mm measurement = x50 Object Image Size Actual size Magnification Salmonella 1.5cm 0.003mm x 30mm ÷ Crystal 3cm 0.05mm x 0.05mm = x600 White Cell 20mm 20µm x Dust 25mm 0.1cm x 20,000µ ÷ Finger Nail 5mm 1.5cm x 2020µm 5mm ÷ 2015mm 25mm ÷ = x1000 m 201mmm = x0.3 = x25 HPL PIT POINT Write down one thing that has helped you be successful in today's lesson Write down one thing that you need to do to improve  Reflection Assess yourself / your partner – how far have you come on your learning journey ? Write which of the following you have done in today’s lesson. define and differentiate between a tissue, organ, and organ system with clear examples. Understand how different tissues form organs and how organs function in an organ system. Can explain the concept of magnification and resolution. Accurately calculate magnification using the given formula. Not happy with this. OK with this. Very happy with this.  Home work Questions 1. What magnification would make an image 48 μm wide from an object 6 nm wide? 2. An image is 50 mm wide when viewed under 25x magnification. How big is the object? 3. If magnification is 20x and the object is 2 mm wide, how wide is the image? 4. An image of a cell has a diameter of 8 mm and the actual cell has a diameter of 20 μm. What is the magnification?  Challenge: standard form Standard form is useful when writing down very large (or very small) numbers. Write the following out as a normal number. a) 9.92 x 106 = b) 7 x 100 = c) 7 x 105 = d) 5.255 x 102 = 9920000 7 700000 525.5