1.
What do animal and plant cells have in common?
Correct Answer
A. Cell membrane, nucleus
Explanation
Animal and plant cells have in common a cell membrane, which is a protective barrier that controls the movement of substances in and out of the cell, and a nucleus, which is the control center of the cell that contains genetic material and regulates cell activities.
2.
What shape best describes a red blood cell?
Correct Answer
D. Biconcave
Explanation
A red blood cell is best described as biconcave because it has a unique shape that is concave on both sides, resembling a shallow disc or a donut. This shape allows for increased surface area, which is important for the cell's main function of transporting oxygen and carbon dioxide throughout the body. The biconcave shape also provides flexibility, allowing the red blood cell to squeeze through narrow capillaries and deliver oxygen efficiently to tissues.
3.
What are the tubes called that carry water to the leaf?
Correct Answer
B. Xylem
Explanation
Xylem is the correct answer because it is the type of tissue in plants that transports water and nutrients from the roots to the leaves. The xylem tubes, also known as vessels, are composed of specialized cells that form a continuous network throughout the plant, allowing for the upward movement of water against gravity. This transport system is crucial for the survival and growth of plants, as it ensures that water and essential nutrients reach all parts of the plant, including the leaves where photosynthesis takes place.
4.
Which organs turns waste products into urine?
Correct Answer
C. Kidney
Explanation
The kidney is responsible for turning waste products into urine. It filters the blood, removing waste products, excess water, and toxins, which are then excreted as urine. The kidney plays a crucial role in maintaining the body's fluid balance and removing waste from the bloodstream.
5.
Where does photosynthesis take place?
Correct Answer
D. The leaf
Explanation
Photosynthesis takes place in the leaf. This is because the leaf contains specialized structures called chloroplasts, which contain chlorophyll. Chlorophyll is responsible for capturing sunlight, which is then used to convert carbon dioxide and water into glucose and oxygen through the process of photosynthesis. The leaf's large surface area and thin structure allow for maximum exposure to sunlight, making it the ideal location for photosynthesis to occur.
6.
What is a cell membrane for?
Correct Answer
C. Controlling what passes in and out of the cells
Explanation
The cell membrane is responsible for controlling what passes in and out of the cells. It acts as a barrier, allowing certain substances to enter or exit the cell while blocking others. This selective permeability is crucial for maintaining the internal environment of the cell and regulating its activities. By controlling the movement of molecules, ions, and nutrients, the cell membrane ensures that the cell functions properly and maintains homeostasis.
7.
Which statement is true for cytoplasm?
Correct Answer
D. Where the cell's chemical reactions take place
Explanation
The cytoplasm is where the cell's chemical reactions take place. It is a gel-like substance that fills the cell and contains various organelles, such as ribosomes and mitochondria, which are responsible for carrying out the cell's metabolic processes. These chemical reactions include processes like protein synthesis, energy production, and cellular respiration. The cytoplasm provides a medium for these reactions to occur and facilitates the movement of molecules and organelles within the cell.
8.
What is meant by menstruation?
Correct Answer
B. Blood from the uterus wall is lost
Explanation
Menstruation refers to the monthly process in which blood and tissue from the inner lining of the uterus is shed through the vagina. This occurs when an egg is not fertilized and pregnancy does not take place. The shedding of the uterine lining is accompanied by bleeding, which is commonly known as a period. Menstruation is a natural part of the menstrual cycle and typically lasts for a few days to a week. It is a sign that a woman's reproductive system is functioning properly and is not pregnant.
9.
What is meant by ovulation?
Correct Answer
A. An egg is released
Explanation
Ovulation refers to the process in which an egg is released from the ovary. This typically occurs in the middle of a woman's menstrual cycle. During ovulation, the egg travels down the fallopian tube, where it can potentially be fertilized by sperm. If fertilization occurs, it may lead to pregnancy. If fertilization does not occur, the egg disintegrates and is expelled from the body during menstruation. Ovulation is a crucial step in the reproductive cycle and is necessary for conception to take place.
10.
Tobacco contains a very poisonous substance. Which one of the following is correct?
Correct Answer
C. Nicotine
Explanation
Nicotine is the correct answer because it is a highly poisonous substance found in tobacco. It is a stimulant drug that affects the central nervous system and can be addictive. Nicotine is responsible for the addictive properties of tobacco and is known to have harmful effects on the body, including increasing the risk of heart disease and lung cancer.
11.
Which two properties about hydrogen gas are correct?(Tick 2 options)
Correct Answer(s)
A. Hydrogen does not dissolve in water.
C. Hydrogen has a lower density than air.
Explanation
Hydrogen does not dissolve in water because it is a nonpolar molecule and water is a polar solvent. The difference in polarity prevents hydrogen from forming strong enough interactions to dissolve in water. Hydrogen also has a lower density than air because it is a lighter gas. This property allows hydrogen to rise and disperse in the atmosphere.
12.
What is produced when hydrogen burns in air?
Correct Answer
A. Hydrogen Oxide or Water.
Explanation
When hydrogen burns in air, it combines with oxygen to form water or hydrogen oxide. This is a chemical reaction known as combustion, where hydrogen acts as the fuel and oxygen acts as the oxidizer. The reaction can be represented by the equation: 2H2 + O2 -> 2H2O. Therefore, the correct answer is Hydrogen Oxide or Water.
13.
Which three elements are combined in ethanol?
Correct Answer
A. Carbon, hydrogen & oxygen
Explanation
Ethanol is an organic compound that consists of carbon, hydrogen, and oxygen atoms. Carbon is the backbone of the molecule, with two hydrogen atoms attached to each carbon atom. Additionally, there is an oxygen atom bonded to one of the carbon atoms. This combination of elements forms the chemical formula C2H5OH, which represents ethanol.
14.
What do we call a mixture of sodium chloride and water?
Correct Answer
C. Solution
Explanation
A solution is a mixture of two or more substances, where one substance (the solute) is dissolved in another substance (the solvent). In this case, sodium chloride is the solute and water is the solvent. Therefore, the correct answer is "Solution."
15.
Which gas, found in the air, dissolves in rain water to form acidic rain?
Correct Answer
C. Carbon dioxide
Explanation
Carbon dioxide dissolves in rain water to form carbonic acid, which is responsible for making rainwater acidic. When carbon dioxide reacts with water, it forms carbonic acid (H2CO3), which lowers the pH of rainwater and makes it acidic. This process is known as acid rain and can have harmful effects on the environment, including damage to plants, buildings, and aquatic ecosystems.
16.
How does carbon dioxide cause global warming?
Correct Answer
C. It destroys the ozone layer
17.
Tick the correct statements below
Correct Answer(s)
B. Sugar is more soluable in hot water than cold water
C. Most solutes are more soluble at high tempaeratures
E. When no more solute can dissolve in a solution it has formed a saturated solution
Explanation
The answer is correct because it accurately identifies the statements that are true. Sugar is indeed more soluble in hot water than cold water, as higher temperatures increase the kinetic energy of the water molecules, allowing them to more effectively break down the sugar molecules. Similarly, most solutes are more soluble at high temperatures because the increased energy facilitates the dissolution process. Lastly, when no more solute can dissolve in a solution, it has reached its saturation point and is considered a saturated solution.
18.
Ice is an example of which state of matter?
Correct Answer
C. Solid
Explanation
Ice is an example of the solid state of matter because it has a definite shape and volume. In the solid state, particles are closely packed together and vibrate in fixed positions. Ice is formed when water molecules lose energy and slow down, causing them to arrange themselves in a regular pattern. This regular arrangement gives ice its solid structure.
19.
What happens to particles when they are heated?
Correct Answer
C. They move around more
Explanation
When particles are heated, they gain energy and their kinetic energy increases. This causes the particles to move around more vigorously and with greater speed. Therefore, the correct answer is that particles move around more when they are heated.
20.
Which particles are found in shells around a nucleus?
Correct Answer
C. Electrons only
Explanation
Electrons are the particles found in shells around a nucleus. Protons and neutrons are located within the nucleus itself. Electrons have a negative charge and are responsible for the chemical behavior of atoms. They orbit the nucleus in specific energy levels or shells, each with a maximum number of electrons it can hold. This arrangement of electrons in shells determines the chemical properties and reactivity of an element. Therefore, the correct answer is electrons only.
21.
How far will a bus travel in 5 hours if its speed is 60 km/hour?
Correct Answer
C. 300 km
Explanation
The bus is traveling at a speed of 60 km/hour for 5 hours, so we can calculate the distance traveled by multiplying the speed by the time: 60 km/hour * 5 hours = 300 km.
22.
A sloping straight line on a distance-time graph tells us that the object is:
Correct Answer
E. Moving at a constant speed
Explanation
A sloping straight line on a distance-time graph indicates that the object is moving at a constant speed. This means that the object covers the same distance in the same amount of time, without any change in its velocity. The slope of the line represents the speed of the object, with a steeper slope indicating a higher speed and a shallower slope indicating a lower speed. Therefore, a sloping straight line on a distance-time graph suggests that the object is not accelerating or decelerating, but rather maintaining a steady velocity.
23.
Which of the following will happen if balanced forces are applied to an object?
Correct Answer
C. It may travel at a constant speed
Explanation
If balanced forces are applied to an object, it means that the forces acting on the object are equal in magnitude and opposite in direction. In this case, the object will not accelerate or decelerate because there is no net force acting on it. However, it may continue to move at a constant speed if it was already in motion before the balanced forces were applied. The object will not change direction unless an external force is applied to it. It may also not move slightly because the balanced forces cancel each other out.
24.
Friction between the surfaces can be increased by :
Correct Answer
B. Roughening the surfaces
Explanation
Roughening the surfaces increases friction because it creates more points of contact between the two surfaces. When the surfaces are rough, the irregularities on one surface can interlock with the irregularities on the other surface, resulting in a greater resistance to motion. This increased contact area leads to a stronger force of friction between the surfaces, making it harder for them to slide or move past each other.
25.
What pressure is created when a force of 64 N is applied over an area of 4 metre square?
Correct Answer
C. 16 Pa
Explanation
The pressure created when a force of 64 N is applied over an area of 4 square meters can be calculated using the formula pressure = force/area. Substituting the given values, we get pressure = 64 N / 4 m^2 = 16 Pa.
26.
A ray of light strikes the surface of a plane mirror with an angle of incidence of 60 degree. What is its angle of reflection?
Correct Answer
C. 60 degree
Explanation
The angle of incidence is the angle between the incident ray and the normal to the surface of the mirror. According to the law of reflection, the angle of reflection is equal to the angle of incidence. Therefore, if the angle of incidence is 60 degrees, the angle of reflection will also be 60 degrees.
27.
When a ray of light enters a glass block it
Correct Answer
B. Slows down
Explanation
When a ray of light enters a glass block, it slows down. This is because the speed of light is slower in a denser medium like glass compared to air or vacuum. As the light ray enters the glass block, it interacts with the atoms and molecules of the glass, causing it to slow down. This change in speed is what leads to the bending or refraction of the light ray as it enters the glass block.
28.
We measure the frequency of a wave in:
Correct Answer
B. Hertz
Explanation
The frequency of a wave refers to the number of complete cycles or oscillations that occur in one second. Hertz is the unit used to measure frequency, representing one cycle per second. Therefore, hertz is the appropriate unit to measure the frequency of a wave. Metres, metres per second, newton, and hertz per second are not suitable units for measuring frequency.
29.
Heat is transferred along a metal rod by:
Correct Answer
C. Conduction
Explanation
Heat is transferred along a metal rod by conduction. Conduction is the process of heat transfer through direct contact between particles of a substance. In this case, the metal rod conducts heat as the vibrating particles in one end of the rod collide with neighboring particles, transferring their energy and causing them to vibrate as well. This process continues along the rod, allowing heat to be transferred from one end to the other. Convection involves the transfer of heat through the movement of a fluid, radiation is the transfer of heat through electromagnetic waves, and reflection is the bouncing back of heat without transfer. Nuclear power is not a method of heat transfer.
30.
Current is measured with a:
Correct Answer
E. Ammetre
Explanation
An ammeter is used to measure current in a circuit. It is connected in series with the component or circuit being measured, allowing the flow of current to pass through it. The ammeter has a low resistance, ensuring that it does not significantly affect the current being measured. By measuring the current, the ammeter provides valuable information about the amount of electric charge flowing through the circuit, helping to monitor and troubleshoot electrical systems.