I. Choose the correct answer for the following questions.

1. Which of the following is not a property of life? 

a. Populations of organisms rarely change over time. 

b. Living things exhibit complex but ordered organization. 

c. Organisms take in energy and use it to perform all of life’s activities. 

d. Organisms reproduce their own kind. 

2.  Which of the following is the correct procedure of scientific method?

a. Experiment conclusion application Question observation

b. Question observation experiment analysis prediction result

c. Observation question hypothesis prediction, experiment results  conclusion 

d. Observation question opinion conclusion hypothesis 

3. Hypothesis in biology is best described as... 

a. possible explanation of an observation. 

b. an observation that supports a theory. 

c. a general principle that explains some aspect of life.

d. an unchanging statement that correctly predicts some aspect of life. 

4. Which of the following is not the correct method of handling chemicals?

a. wearing a disposable respirator mask when handling chemicals that are toxic

b. never allow laboratory chemicals to contact your bare skin 

c. never put chemicals open

d. return and pour the unused (left over) chemicals to its original container

Answer 

1.  A     2. C     3. A      4.  D  

II. Write short answer for the following questions 

5. Write the main difference between light and Electron microscope. 

  • Light microscopes uses a beam of light to view specimens.

  • Electron microscope uses a beam of electrons (instead of a beam of light) and electromagnets (instead of glass lenses) to enlarge the image of an object.

6. Write the function of the following common laboratory tools.

7. Look at the following laboratory safety signs and write their meaning.

8. Why does a microscope have several objective lenses? 

  • Microscope have several objective lenses to facilitate a quick change in the  magnification of a specimen and high power objective lens provides a  higher degree of magnification, which allows to zoom in closer to the object being studied and see more detail and a lower power lens will provide a wider field of vision.

9. What will happen to the field of view in a microscope as you close the diaphragm? Explain your answer. 

  • The diaphragm on the microscope is used to change the amount of light that is being allowed to enter through the slide. 

  • Closing the diaphragm will decrease the amount of illumination of the specimen but increases the amount of contrast. 

  • The light to the field is reduced as the diaphragm is closed. Smaller diameter and therefore lets in less light.

10. Why should you always focus a microscope by moving the objective lens away from the specimen? 

  • In order to focus on an object, one should move the stage away from the objective lenses rather than towards each other in order to prevent crashing the lens into the slide.

11. Explain the importance of adding oil immersion when using high power objective? How? 

  • Oil immersion is a technique used to increase the resolving power of a microscope and improve the image quality. 

  • The oil immersion increase the resolving power by decreases the light refraction (bending of the light), allowing more light to pass through the specimen to the objectives lens. 

  • Oil immersion eliminate any air gaps and loss of light due to refraction and maximizes the amount of light that goes through the objective lens. 

12. List at least three field tools used by biologists. 

  • Insect nets

  • Fishing net

  • GPS(Global positioning system)

Last modified: Kibxata, 30 Fulbaana 2025, 9:43 AM