Grade 9 Life Science Skills Notes

Ecology, Health, Microbiology, Structural Genetics, Immunology, and Genomics

Topics are interdisciplinary, including living nanotechnology and biocontrol monitoring.
Life sciences include the study of physiology, ethology, and psychology, with fields related to animals, technology, and organisms.
Disciplines include biology, neuroscience, immunotherapy, human medicine aspects, pharmacology, imaging, and science.
Research areas are in biotechnology and biomaterials.
Teachers: Ms. S. Rosa & Ms. H. Jali

Developing Scientific Skills

How to Draw a Scientific Drawing

No artistic ability is needed, only accurate observation skills.
Required materials: sharpener, HB pencil, soft eraser, and ruler.
Diagrams must have a detailed heading below the drawing, including object name, source, and magnification (if relevant).
Diagrams should be centered on the page and be of reasonable size (at least half a page).
Use smooth, continuous, clear lines.
Do not shade, color, or sketch.
Dense areas should be stippled (dotted).
Label lines should be in pencil, pointing to the actual part, not crossing each other, and ending at the same point.
Labels can be in pen or pencil, neatly written on the right side, one below the other.

Laboratory Apparatus

You should know the name of each piece and its basic use.

Test Tube Rack: To hold test tubes during experimental procedures.
Pipette: For exact measurements of small amounts of liquid.
Test Tube Holder: To hold test tubes while heating.
Erlenmeyer Flask: Used to contain reaction solutions.
Thermometer: For measurement of temperature.
Test Tube: Reaction vessel for small volumes.
Beaker: Used to contain reactions.
Stirring Rod: For stirring chemicals.
Dropper: For measuring out very small volumes of liquid.
Volumetric Flask: For accurately measuring large volumes of liquid.
Funnel: To easily transfer liquids and for filtration.
Graduated Cylinder: For accurately measuring volumes of liquid.
Bunsen Burner: Used for heating chemicals.
Evaporating Dish: Used for evaporation of liquids.
Watch Glass: Used to cover beakers.
Gas Collecting Bottle: To collect gases.
Safety Goggles: To protect your eyes in the lab.
Rubber Stoppers: Used to seal flasks.
Spot Plate: For microscale reactions.
Crucible: For heating to very high temperatures.
Mortar and Pestle: For grinding solids into fine powder.
Test Tube Brush: Used to clean test tubes.
Spatula: Used to transfer solid chemicals.

Laboratory Safety Rules

Access

No student is allowed in the lab without a teacher.
The laboratory storeroom is off-limits to students.

Equipment + Chemicals

Do not touch taps, gas taps, equipment, or chemicals without permission.
This includes smelling, tasting, or mixing chemicals.
Report all breakages to the teacher immediately.
Do not leave fragments in the sink, on the bench, or on the floor.

Procedures

Always listen carefully to instructions before starting an experiment.
Follow instructions precisely.
Never breathe in deeply when smelling a chemical; waft the gases towards you with your hand.

Waste Disposal

Never throw solid substances into the sink; place them in the waste beaker or dustbin.
Do not throw hot or burning substances into the rubbish bin.
Do not wash liquid substances down the drain unless permission is given.

General Safety

Notify the teacher immediately in case of burns, injuries, or allergic reactions.
Running or boisterous behavior is not allowed in the laboratory.
No eating or drinking is permitted.
Notify the teacher of any spillages or substances left on the bench before touching or attempting to clean up.
Clean up after yourself and wash your hands thoroughly before leaving the laboratory.

Specimen

All living specimens are to be treated with care and respect.

Important Terms

Independent variable: (Definition not provided in the text.)
Dependent variable: (Definition not provided in the text.)

How to Draw a Table

A table must have a heading that includes both independent and dependent variables (placed above the table).
Columns and rows must be headed, with units included in the headings.
No units appear in the body of the table.
The table must be neatly drawn with a ruler and fully ruled off.
Example: Table to compare the percentage of final results between male and female students in Grade 9. Results Percentage (%)

How to Draw Graphs

A graph must have a heading that includes both the independent and dependent variables (placed above the graph).
The horizontal axis (X-axis) shows the values of the independent variable.
The vertical axis (Y-axis) shows the values of the dependent variable.
Each axis must be labeled with the variable and unit (e.g., Time (minutes)). This needs to be underlined.
Draw a line along each axis and draw an arrowhead at the end of each.
If necessary, supply a key.
Color may be used to plot and draw lines. (Do NOT use highlighters, only sharp pencil crayons may be used to color in and fine liners to do patterns / draw a line graph or outline a bar graph.)
You must choose a scale which is simple and easy to use – both your x and y axes scales need to be consecutive respectively.

Types of Graphs

Line Graph

Has a continuous sequence of information on both sets of axes.
The position of each number plotted must be marked using a SHARP dot and a neat circle around it.
Both the independent and dependent variables are numbers.
Example: Line graph to show the production achieved from 1992 to 1997: x y Production Time (Years)

Bar Graph

The independent variable represents separate data groups.
All bars are the same width.
There are equal spaces between the bars, as there is no set order to the groups of information.
Never plot on the origin (y-axis).
The scale on your y-axis needs to be consecutive.
Example: Bar graph to show the different types of pets owned by a number of people in a small community: y x Pets Number of people

Pie Graph

Usually given in percentages – percentages recorded in the graph with percentage sign (%)
Conversion: 1 \% = 3.6^\circ (\%$ x 3.6 = ^{\circ}$$)
Colour may be used. (No highlighters.)
Always supply a key
Example: Pie graph to show the percentage of the most popular sports done in a school:

What to do if the numbers are far greater than zero

The point at where the x and y axes meet is called the origin and is usually zero. If points are left out between 0 and the first number plotted, then two parallel diagonal lines are drawn on the respective axis.

Activity 1

In the block below, tabulate the information from the pie graph found at the bottom of page 7.

Activity 2

Question 1: The table below shows the monthly budget spent by an individual on various items.

ITEM MONTHLY BUDGET (RAND)
Rent 6 000
Electricity 3 000
Food 2 500
Water 1 500
Transportation 2 000
Entertainment 1 000
Other 900

Study the information in the table and then answer the following questions:

Using a piece of graph paper, draw a bar graph to show the monthly budget spent by an individual on various items. (12)
Which item is the most expensive? (2)
State the following:
a. independent variable: (1)
b. dependent variable: (2)
Why is it important to keep a budget?

Question 2: Table to compare the distance run (km2) between Selene and Joey over a period of five hours.

TIME (HOURS) DISTANCE RUN (KM2)
SELENE JOEY
1 10 10
2 25 20
3 30 35
4 45 40
5 50 45

Study the information in the table above and then answer the following questions:

Using a piece of graph paper, draw a line graph to compare the distance run (km2) between Selene and Joey over a period of five hours. (12)
State the following:
a. independent variable: (2)
b. dependent variable: (2)

Question 3: Complete the table below and then present the following information in the form of a pie graph.

Table to show the percentage of usage from various categories on a tablet.

CATEGORY TABLET PERCENTAGE (%) DEGREE (°)
Social networking 15
Games 57
Music 13
Videos 3
News 4
Other 8

Heading:

Drawing a Flow Chart

A flow chart shows the cohesive flow of information about a specific topic.
Focus on what the question is asking and identify the required topic.
Create an informative heading (e.g., Flow chart to show…).
Each new point needs to be written one below the other, separated by an arrow to show the link.
Example: Flow chart to show the process of photosynthesis
- Plants take in carbon dioxide from the air and water from the soil.
- Carbon dioxide combines with the water in the soil the presence of sunlight.
- This chemical reaction results in the production of glucose and oxygen.
- Plants use the glucose as their food source and people and other animals will use the oxygen to survive.

Activity 3

The following information extract describes the process of cellular respiration in a mitochondrion. Read the article below, and then draw a flow chart using the information given.
Cellular respiration is the process in which food is broken down and energy is released. Oxygen diffuses into the body and carbon dioxide diffuses out of the body. Oxygen is needed for cellular respiration, a process that individual cells use to make energy. In this process, carbon dioxide is produced as a waste product. The main purpose of cellular respiration is to make energy, or ATP. ATP is the energy currency of the cell and is needed to carry out all cellular functions. This process occurs in an organelle known as a mitochondrion. Mitochondria are found in both plant and animal cells.

Scientific Method (Investigations)

The first step in an investigation is observation - we notice something happening. We then might ask questions, in order to try to decide why something is happening. From the answers given we make intelligent guesses as to why the event is happening. We write down the most likely answer as a hypothesis i.e. a hypothesis is a statement of what one suspects to be a fact.
The next step is to design, conduct and write up an experiment to test the hypothesis.

Designing an Investigation

State the problem/question that you want to answer. State it clearly and briefly, and remember the question mark.
Write down all the possible reasons you think might be causing the result you see.
Choose the reason you think most likely. This will be the variable you will test.
Write this choice down as a statement where you predict the outcome of the investigation. This is the hypothesis. The hypothesis must be stated as specifically as possible and must be directly related to the question.
The variable you will test is called the independent variable. Decide how you are going to change it.
Decide what you will measure or observe. This is the resulting (dependent) variable. Decide how to measure it.
We need to make sure that we are only investigating one problem at a time. If we succeed then we say the test is fair. To make a test valid we must control all the variables except the one we are testing. Plan how all the other variables will be kept constant.
Decide how many times you will need to repeat the experiment in order to get a reliable result.

Writing up an Investigation

Write down the aim i.e. state what you want to investigate. This is similar to the hypothesis but must be of a testable experiment. The aim should read: To show / to investigate / to find out …
List all the apparatus and materials required (e.g. water). (Sometimes a diagram is also drawn) The apparatus sizes must be included e.g. 100 ml beaker.
Write up the method i.e. what you will be doing. Remember that using just your notes, a complete beginner should be able to repeat your investigation correctly and accurately.

Rules for Writing the Method:

All points must be numbered and in full sentences.
Points must be in chronological order.
Points must be in passive voice.
If written up at the end of the task, points must be in past tense.
Note quantities used e.g. 10 ml of water was placed …..
Note what you will be measuring / looking for; how you will do the measuring and how often / when the measurements will be taken.
Note how long the experiment was left to run and under what conditions (to ensure that controlled variables were controlled)
Note how the results will be recorded e.g. on a table

After observing, measuring and calculating, record the results. The main ways to record results are in the form of drawings, descriptions, tables and graphs.

Note: No explanation as to why something happened should be given here.

Analyze the results and draw conclusions as to whether your hypothesis was correct or incorrect. State what actually occurred and provide evidence.
Evaluate the experiment. Mention if you feel some experimental error has affected the results.

A Good Experiment Would Be:

Valid i.e. there would be only two variables – the input and outcome.
Reliable i.e. if the experiment was repeated it would give the same results. The only way to ensure this is to do the investigation several times and take the average result.
Relevant i.e. test what the hypothesis asked.

Some Important Definitions:

Hypothesis: An explanation of an observed event. In a scientific experiment, it must be testable by means of an investigation.
Independent variable: A condition that was changed systematically in an experiment.
Resultant variable: The effect or outcome as a result of changing another variable.
Controls: Variables which are not allowed to vary in an experiment.
Observation: What you saw.
Inference: A conclusion drawn from a series of observations.