WorksheetsWelcome Back (Sec 4 Bio)
Total questions: 14
Worksheet time: 10mins
When trying to view a blood smear under the microscope, a student placed a drop of blood on a glass slide and added a drop of distilled water to dilute it before placing the coverslip over it.
When viewed, the slide appeared to be empty of cells. Which of the following best explains this?
The blood cells had undergone bursting.
The water caused the cells to crenate.
The blood had dried before the water was added.
The drop of water diluted the blood too much so the cells were too far away from each other.
A few drops of coconut oil were added to 2 cm3 of pure ethanol. 2 cm3 of water were then added after it was shaken for a few seconds.
What would most probably be observed after shaking the mixture?
pink solution
clear solution
white emulsion
violet colouration
The diagram shows the reaction between substances J and K.
Which one of the following statements is true?
N and O are the substrates.
K and M are different substances.
J is the enzyme and K is the substrate.
K contains an active site which is complimentary to J.
The diagram shows part of the circulatory system.
Which blood vessel contains blood with the most concentration of glucose after a meal rich in carbohydrates?
A
B
C
D
Pepsin is an enzyme that is secreted in our stomach to digest protein.
Which one of the following graphs accurately shows the rate of reaction of pepsin against pH?
A geranium plant has leaves that are green in the centre but white around the edges. The plant is destarched and then has one of its leaves partly covered with black paper on both sides of the leaf, as shown.
The plant is placed in bright light for 48 hours. The leaf is then tested for starch. Which diagram correctly shows the areas that contain starch?
The graph shows the rate of photosynthesis at two different levels of carbon dioxide concentration at 20oC.
From the graph, identify the factors most likely to limit the rate of photosynthesis at points X and Y.
X: light intensity, Y: carbon dioxide concentration
X: Temperature ; Y: light intensity
X: carbon dioxide concentration, Y: temperature
X: light intensity ; Y: temperature
A leafy shoot was placed in a beaker containing a blue dye and then examined 5 hours later.
Which statement explains the change in appearance?
Blue dye stains cells in the leaves.
Blue dye moves through the xylem.
Blue dye moves up the stem by osmosis.
Blue dye diffuses through the cells of the plant.
The diagram shows a component found in blood.
What is the function of this component?
To kill bacteria
To transport oxygen
To transport carbon dioxide
To clot blood during injuries
A woman has been smoking heavily for many years. A lot of dust and micro-organisms enter her lungs.
Which statement explains why this occurs?
Her arteries are blocked with tar.
She is addicted to nicotine
The cilia in the trachea have been paralysed.
The surface area of her lungs is reduced.
