9th Grade: Basic Science Practice Test! 2020 Trivia Quiz
The human body is a scientific wonder, and in grade 9, we got to cover most of the systems in the human body. Are you looking for a 9th grade: basic science practice test for the upcoming final science exams? This 2020 trivia quiz is perfect for you as it includes every topic covered in the whole year. Give it a try!
Questions and Answers
- 1.
What is the function of larynx?
- A.
To provide a patent airway, to route air and food into the proper channels, to function in voice production.
- B.
Attaches to the hyoid bond, continuous with the trachea posteriorly.
- C.
Have no function in sound production.
- D.
Folds vibrate to produce sound as air rushes up from the lungs.
Correct Answer
A. To provide a patent airway, to route air and food into the proper channels, to function in voice production.Explanation
The larynx functions to provide a patent airway, meaning it allows for the passage of air without obstruction. It also plays a role in routing air and food into the proper channels, ensuring that air goes to the lungs and food goes to the esophagus. Additionally, the larynx is involved in voice production, as the folds within it vibrate to produce sound when air from the lungs passes through.Rate this question:
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- 2.
Why is oxygen important to blood and to the cells?
- A.
Oxygen helps the blood to clot.
- B.
Oxygen brings food to the cells.
- C.
Oxygen is necessary for cell growth and energy.
- D.
Oxygen is not important -- carbon dioxide is the most important substance to the body.
Correct Answer
C. Oxygen is necessary for cell growth and energy.Explanation
Oxygen is necessary for cell growth and energy because it plays a crucial role in the process of cellular respiration. During cellular respiration, oxygen is used to break down glucose molecules, releasing energy that is used by the cells for various metabolic activities. Additionally, oxygen is also involved in the synthesis of ATP, the primary energy currency of cells. Without oxygen, cells would not be able to generate enough energy to carry out their functions effectively, leading to impaired cell growth and overall cellular dysfunction.Rate this question:
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- 3.
Which type of blood vessels carries blood away from the heart?
- A.
Veins
- B.
Arteries
- C.
Arteries
- D.
Arteries, veins and capillaries
Correct Answer
A. VeinsExplanation
Veins carry blood away from the heart. Unlike arteries, which carry oxygenated blood away from the heart to the rest of the body, veins carry deoxygenated blood back to the heart. This deoxygenated blood is then pumped to the lungs to pick up oxygen before being circulated throughout the body again. Veins have thinner walls and contain valves to prevent the backflow of blood.Rate this question:
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- 4.
What is the function of the blood vessels and capillaries?
- A.
They pump blood to the heart.
- B.
They filter impurities from the blood.
- C.
They carry blood to all parts of the body.
- D.
They carry messages from the brain to the muscles.
Correct Answer
A. They pump blood to the heart. -
- 5.
When we breathe in, we inhale many gases, including oxygen. What happens to the gases that the body can't use?
- A.
They are exhaled.
- B.
They are changed into oxygen by the lungs.
- C.
They circulate through the body and are disposed of later.
- D.
They are absorbed into the digestive system and used to create energy.
Correct Answer
A. They are exhaled.Explanation
When we breathe in, our body takes in various gases, including oxygen. However, not all of these gases can be utilized by the body. The gases that the body can't use are exhaled. Through the process of exhalation, these gases are expelled from the body and released back into the environment. This allows the body to get rid of the gases that are not needed and make space for fresh oxygen to be inhaled.Rate this question:
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- 6.
What body structure protects the lungs from outside harm?
Correct Answer
rib cageExplanation
The rib cage is a bony structure that surrounds and protects the lungs. It consists of the ribs, sternum, and thoracic vertebrae. The ribs act as a barrier, shielding the delicate lungs from external forces and potential injuries. They provide a sturdy framework that helps maintain the shape and position of the lungs, preventing them from being crushed or damaged. Additionally, the rib cage also plays a crucial role in the process of breathing by expanding and contracting to allow for the movement of air in and out of the lungs.Rate this question:
- 7.
Which of the choices below is not a functional process performed by the respiratory system?
- A.
Pulmonary ventilation
- B.
Transport of respiratory gases
- C.
External respiration
- D.
pulmonary respiration
Correct Answer
B. Transport of respiratory gasesExplanation
The respiratory system is responsible for many processes, including pulmonary ventilation, external respiration, and pulmonary respiration. These processes involve the movement of air in and out of the lungs, the exchange of gases between the lungs and the blood, and the exchange of gases between the blood and the body's tissues. However, the transport of respiratory gases is not a process performed by the respiratory system. This task is carried out by the circulatory system, specifically the cardiovascular system, which transports oxygen from the lungs to the body's tissues and removes carbon dioxide from the tissues to be exhaled.Rate this question:
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- 8.
Exchange of air occurs in _______ which are also known as 'air sacs'.
Correct Answer
alveoliExplanation
The correct answer is alveoli. Alveoli are small, thin-walled sacs located at the end of the bronchioles in the lungs. They are responsible for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. Oxygen enters the bloodstream through the walls of the alveoli, while carbon dioxide, a waste product, is expelled from the body through exhalation. Alveoli increase the surface area available for gas exchange, allowing for efficient oxygenation of the blood and removal of carbon dioxide.Rate this question:
- 9.
Write the correct sequence of the pathway through which air travels after entering the body.
- A.
Larynx, pharynx, trachea bronchioles
- B.
Pharynx, larynx, trachea, bronchioles
- C.
Pharynx, larynx, bronchioles, trachea
- D.
Pharynx, trachea, larynx, bronchioles
Correct Answer
B. pHarynx, larynx, trachea, bronchiolesExplanation
Air enters the body through the pharynx, then passes through the larynx, which is commonly known as the voice box. From there, it travels down the trachea, also known as the windpipe, and finally reaches the bronchioles, which are small airways in the lungs. Therefore, the correct sequence of the pathway through which air travels after entering the body is Pharynx, larynx, trachea, bronchioles.Rate this question:
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- 10.
What happens to your lungs when you breath in?
- A.
They absorb carbon dioxide
- B.
They manufacture glucose
- C.
They push up the diaphragm
- D.
They expand
Correct Answer
D. They expandExplanation
When you breathe in, your lungs expand. This is because the diaphragm, a muscle located at the base of the lungs, contracts and moves downward, creating more space in the chest cavity. As a result, the lungs are able to take in more air, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled. This expansion of the lungs is crucial for the process of respiration, enabling the exchange of gases between the lungs and the bloodstream.Rate this question:
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- 11.
Advantages to using the garden pea for Mendel's experiments included all listed below except
- A.
True-breeding varieties were scarce.
- B.
He could expect to observe segregation of traits among the offspring.
- C.
They have relatively short generation time.
- D.
Sex organs of the pea are enclosed within the flower.
Correct Answer
A. True-breeding varieties were scarce.Explanation
The garden pea was advantageous for Mendel's experiments because he could expect to observe segregation of traits among the offspring, they have a relatively short generation time, and the sex organs of the pea are enclosed within the flower. However, true-breeding varieties were not scarce, as Mendel was able to find and work with true-breeding pea plants.Rate this question:
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- 12.
When Mendel crossed pure-breeding purple and white-flowered pea plants, the dominant to recessive ratio in the F1 generation was
- A.
3:1
- B.
4:0
- C.
4:1
- D.
2:1:1
Correct Answer
B. 4:0Explanation
When Mendel crossed pure-breeding purple and white-flowered pea plants, all the offspring in the F1 generation had purple flowers. This indicates that the purple flower trait is dominant over the white flower trait. Since there were no white-flowered plants in the F1 generation, the ratio of dominant to recessive traits is 4:0.Rate this question:
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- 13.
On which of the following chromosomes are sex-linked traits carried?
- A.
13
- B.
18
- C.
Y
- D.
X
Correct Answer
D. XExplanation
Sex-linked traits are carried on the X chromosome. The Y chromosome is responsible for determining male sex, while the X chromosome is present in both males and females. Therefore, the correct answer is "x" as it represents the X chromosome.Rate this question:
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- 14.
In Mendel's F2 generation of the purple and white flower crossing, the dominant to recessive ratio was
- A.
1:3:1
- B.
3:1
- C.
4:0
- D.
2:1:1
Correct Answer
B. 3:1Explanation
In Mendel's F2 generation, the dominant to recessive ratio was 3:1. This means that for every three plants with the dominant purple flower trait, there was one plant with the recessive white flower trait. This ratio is consistent with Mendel's laws of inheritance, specifically the law of segregation, which states that alleles for a trait separate during gamete formation and randomly recombine during fertilization.Rate this question:
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- 15.
A individual who has two of the same allele is said to be
- A.
Homozygous
- B.
Heterozygous
- C.
Dominant
- D.
Recessive
Correct Answer
A. HomozygousExplanation
An individual who has two of the same allele is said to be homozygous. This means that both alleles for a particular gene are identical. In homozygous individuals, the alleles can be either dominant or recessive. Homozygosity can result in the expression of a specific trait or characteristic, as both alleles are the same and will have the same effect on the phenotype.Rate this question:
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- 16.
In garden peas, height is determined by a single gene with tall being dominate to short. If two heterozygous plants are crossed, what proportion of the tall progeny will be homozygous dominant?
- A.
3/4
- B.
2/3
- C.
1/2
- D.
1/3
Correct Answer
A. 3/4Explanation
When two heterozygous plants are crossed (Tt x Tt), there is a 3/4 chance that the offspring will be tall and a 1/4 chance that they will be short. Among the tall progeny, 1/4 will be homozygous dominant (TT) and 3/4 will be heterozygous (Tt). Therefore, the proportion of the tall progeny that will be homozygous dominant is 1/4 divided by 3/4, which simplifies to 3/4.Rate this question:
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- 17.
Both carotenoids and chlorophylls
- A.
Are pigments
- B.
Absorb photons of all energy ranges
- C.
Contain porphyrin rings
- D.
All of the above
Correct Answer
A. Are pigmentsExplanation
The given correct answer is "are pigments". Both carotenoids and chlorophylls are pigments, which means they are natural substances that give color to plants and other organisms. Pigments are responsible for absorbing light energy and playing a crucial role in photosynthesis. Therefore, all the options provided in the question are correct as carotenoids and chlorophylls are pigments, they absorb photons of all energy ranges, and they contain porphyrin rings.Rate this question:
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- 18.
Water vapor exits and CO2 enters a leaf through the
- A.
Stomata
- B.
Veins
- C.
Cuticle
- D.
Palisade cell
Correct Answer
A. StomataExplanation
Stomata are small openings on the surface of leaves that allow water vapor to exit and carbon dioxide to enter the leaf. These openings are surrounded by specialized cells called guard cells, which can open and close the stomata to regulate gas exchange and prevent excessive water loss. Therefore, stomata is the correct answer for this question.Rate this question:
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- 19.
The oxygen that is released as O2 during photosynthesis came from _____________ molecules.
- A.
Carbon dioxide
- B.
Water
- C.
Light energy
- D.
Chlorophyll
Correct Answer
B. WaterExplanation
During photosynthesis, plants convert carbon dioxide and water into glucose and oxygen. The oxygen molecules released as O2 during photosynthesis come from the water molecules. Through a series of complex reactions, plants use the energy from light (captured by chlorophyll) to break down water molecules, releasing oxygen as a byproduct. This oxygen is then released into the atmosphere as O2.Rate this question:
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- 20.
Circulation loop through lungs where blood of body is oxygenated is classified as
- A.
Pulmonary circulation
- B.
Sytematic circulation
- C.
Digestive circulation
- D.
Lymphatic circulation
Correct Answer
A. Pulmonary circulationExplanation
Pulmonary circulation refers to the circulation loop through the lungs where deoxygenated blood from the body is pumped to the lungs to be oxygenated and then returned to the heart. This process allows for the exchange of carbon dioxide for oxygen in the lungs, ensuring that oxygenated blood is delivered to the body's tissues. Systematic circulation, on the other hand, refers to the circulation of oxygenated blood from the heart to the rest of the body. Digestive circulation relates to the circulation of blood within the digestive organs, while lymphatic circulation is the movement of lymph fluid throughout the lymphatic system.Rate this question:
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- 21.
Left atrium receives oxygenated blood from
- A.
Right atrium
- B.
Lungs
- C.
Right ventricle
- D.
Right atria
Correct Answer
B. LungsExplanation
The left atrium receives oxygenated blood from the lungs. After blood is oxygenated in the lungs, it is carried back to the heart through the pulmonary veins. The pulmonary veins then deliver the oxygenated blood to the left atrium, which pumps it into the left ventricle to be circulated to the rest of the body. The right atrium, right ventricle, and right atria are not involved in receiving oxygenated blood from the lungs.Rate this question:
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- 22.
Blood which heart pumps to lungs is
- A.
Oxygenated blood
- B.
Atria blood
- C.
Lymph fluid
- D.
Deoxygenated blood
Correct Answer
D. Deoxygenated bloodExplanation
The blood that the heart pumps to the lungs is deoxygenated blood. This blood has already delivered oxygen to the body's tissues and has picked up carbon dioxide as a waste product. It is then transported back to the heart and pumped to the lungs where it releases carbon dioxide and picks up fresh oxygen to be delivered to the body again.Rate this question:
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- 23.
The nose, pharynx, and associated structures are all part of the
- A.
Respiratory division
- B.
Lower respiratory system
- C.
Upper respiratory system
- D.
Bronchial tree
Correct Answer
C. Upper respiratory systemExplanation
The nose, pharynx, and associated structures are all part of the upper respiratory system. This system includes the organs and structures involved in the initial stages of respiration, such as the nasal cavity, pharynx, and larynx. These structures are responsible for filtering, warming, and humidifying the air we breathe before it reaches the lower respiratory system, which includes the bronchial tree and lungs.Rate this question:
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- 24.
During inspiration the pressure in the lungs increases.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
During inspiration, the pressure in the lungs actually decreases. When we inhale, the diaphragm and intercostal muscles contract, causing the volume of the thoracic cavity to increase. This increase in volume leads to a decrease in pressure within the lungs, creating a pressure gradient that allows air to flow into the lungs. Therefore, the statement that the pressure in the lungs increases during inspiration is false.Rate this question:
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- 25.
Also known as the voice box.
Correct Answer
larynxExplanation
The question states that the given term is also known as the voice box, and the correct answer is "larynx." The larynx is a part of the respiratory system located in the throat that houses the vocal cords. It plays a crucial role in producing sound and is commonly referred to as the voice box.Rate this question:
- 26.
Which of the following organisms do NOT carry on photosynthesis?
- A.
Plants
- B.
Algae
- C.
Some bacteria
- D.
Animals
Correct Answer
D. AnimalsExplanation
Animals do not carry out photosynthesis. Photosynthesis is the process by which organisms, such as plants and algae, convert sunlight into energy. Animals, on the other hand, obtain their energy by consuming other organisms or organic matter. They do not have the necessary structures, such as chloroplasts, to carry out photosynthesis. Therefore, animals rely on other organisms, such as plants, to produce the energy-rich molecules they need for survival.Rate this question:
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- 27.
The chlorophyll pigments give tomatoes and carrots their color.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The statement is false because chlorophyll pigments are responsible for the green color in plants, not the red or orange color found in tomatoes and carrots. The red color in tomatoes comes from a pigment called lycopene, while the orange color in carrots comes from a pigment called beta-carotene.Rate this question:
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- 28.
The condition where both alleles of a gene are expressed in the phenotype.
Correct Answer
Incomplete DominanceExplanation
Incomplete dominance is the condition where both alleles of a gene are expressed in the phenotype. In this case, neither allele is completely dominant over the other, resulting in a phenotype that is a blend or intermediate of the two alleles. For example, in the case of flower color, if one allele codes for red petals and the other allele codes for white petals, incomplete dominance would result in pink petals. This is different from complete dominance, where one allele is completely dominant over the other and masks its expression in the phenotype.Rate this question:
- 29.
The quality of two heterozygous alleles that are fully expressed in the phenotype.
Correct Answer
Complete DominanceExplanation
Complete dominance refers to a type of genetic inheritance where one allele completely masks the effect of the other allele in a heterozygous individual. In this case, both alleles are fully expressed in the phenotype, meaning that the dominant allele determines the physical trait while the recessive allele has no observable effect. This results in a clear distinction between the dominant and recessive phenotypes, with no blending or intermediate traits.Rate this question:
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