Homework 1 Microscopes

Transcription

1 Homework 1 Microscopes O NO WRITE ON THE PPER 1. opy and complete the following sentences using the word bank below to help you. clearly, lenses, small, cells, structure, magnification (a) ll living things are made up of basic units called. cell is the simplest that can exist on its own. ells are very and cannot be seen with the naked eye. (b) microscope contains that are used to make cells look larger. This increase in size is called. Stains can also be used to help show up cell structures more. Look at this drawing of a microscope. I H F G E

2 2. opy and complete the table below. Letter Name of part What it does I gets a sharp picture slide clip objective lens magnifies mirror 3. (a) What happens to the slide under the microscope when it is moved to the right. (b) escribe what is meant by the field of view. (c) nna prepared a microscope slide to view her cheek cells. alculate the magnification of the cells if she set up her microscope with the following lenses: (i) eyepiece lens at x10 and objective lens at x4 (ii) eyepiece lens at x10 and objective lens at x10 (d) The eyepiece lens always has a magnification of x10. Which objective lens would nna need to use for her cheek cells to appear 400 times larger? Total 10 2

3 Homework 2 Plant and nimal ells 1. Look at the drawing of an onion cell. E a) Name the stain that is used to show up the structures in onion cells more clearly. b) raw a diagram of the cell in your jotter and label parts to E. (c) What is the function of part? 3. Look at the drawing of a cheek cell. F H G a) Which stain is used to show up the structures in a cheek cell more clearly? b) raw a diagram of the cell in your jotter and label parts F to H. 3

4 4. Which three structures are found in both plant and animal cells? 5. The table below shows the length of five different cell types. Type of cell Length in micrometres (1000 micrometres = 1 mm) red blood cell 7 onion 150 rhubarb 200 cheek 50 white blood cell 12 a) raw a bar chart for the information in the table. b) What is the length of a rhubarb cell in millimetres? Total 12 4

5 Homework 3 Microbes 1. Explain what is meant by the term microbe. 2. Name a microbe which can be useful to man Have you ever had a virus? What about a bacterial infection? iseases can cause us to become ill if dangerous microbes are able to enter the body. There a number of ways in which the body defends itself against disease. 3. Give three examples of how the body defends itself against disease? 4. How do vaccinations help the body to fight off diseases? 5. Some types of bacteria can cause harm to humans. Name 2 types of bacteria and the diseases that they cause. (2) Total 8 Homework 5 Parts of a flower 5

6 Homework 4 Puberty and Reproduction 1. escribe what is meant by the word puberty? 2. List two changes that will take place in a girl when she reaches puberty. 3. List 2 changes that will take place in a boy when he reaches puberty. Use the diagram of the female reproductive system below to answer question 4. E 4. opy and complete the following sentences. a) Letter identifies the ovaries. These are where are produced in a female. Structure is the. This is where from the male is deposited during sexual intercourse. b) The fallopian tubes are represented by letter. Fertilised egg cells move down these tubes to structure, known as the, to develop into a foetus. 6

7 Use the diagram of the male reproductive system to answer question a) Which letter identifies the scrotum? b) In which letter of the diagram are sperm produced? c) What is part? d) What is the function of the structure labelled? (4) 6. The table shows the mass of a baby from birth to one year old. ge (months) Mass (kg) raw a line graph to show the change in mass with age. 7. What effect does alcohol have on the developing embryo. Total 14 7