1.
Four different living organisms are shown below.
Which statement is true for all of the organisms shown?
Correct Answer
C. They contain at least one cell.
Explanation
The statement "They contain at least one cell" is true for all of the organisms shown. This is because all living organisms, regardless of their complexity or mode of nutrition, are made up of one or more cells. Cells are the basic structural and functional units of life, and all living organisms, whether they are unicellular or multicellular, possess at least one cell.
2.
Running to escape danger is an action that requires the nervous system to coordinate the interaction of which two body systems?
Correct Answer
B. Muscular and skeletal
Explanation
Running to escape danger requires the coordination of the muscular and skeletal systems. The muscular system provides the force and movement needed for running, while the skeletal system provides the structural support and framework for the muscles to work effectively. Together, these two systems allow the body to generate the necessary speed and agility to escape danger.
3.
The diagrams below show two organisms. How are these two organisms classified?
Correct Answer
D. Different kingdoms, different species
Explanation
The two organisms shown in the diagrams belong to different kingdoms because they have different characteristics and structures. They also belong to different species because they have distinct traits and cannot reproduce with each other. Therefore, the correct classification for these two organisms is different kingdoms, different species.
4.
Which system produces most of the hormones in the human body?
Correct Answer
C. endocrine
Explanation
The endocrine system produces most of the hormones in the human body. This system is responsible for regulating various bodily functions, including growth, metabolism, and reproduction, through the secretion of hormones into the bloodstream. These hormones act as chemical messengers, traveling through the bloodstream to target cells and organs, where they help to control and coordinate various physiological processes. The circulatory system, digestive system, and respiratory system all play important roles in the body, but they do not produce the majority of hormones.
5.
Each body cell of a goldfish contains 94 chromosomes. How many chromosomes are contained in a goldfish sex cell?
Correct Answer
B. 47
Explanation
A goldfish sex cell, also known as a gamete, contains half the number of chromosomes compared to a body cell. Since each body cell of a goldfish contains 94 chromosomes, the sex cell would contain half of that, which is 47 chromosomes.
6.
The diagram below shows a green plant. What is the main function of the plant structure labeled A?
Correct Answer
A. Reproduction
Explanation
The main function of the plant structure labeled A is reproduction. This is because the process of reproduction in plants involves the production of flowers, fruits, and seeds, which are essential for the continuation of the plant species.
7.
Which unit is used to express the amount of energy in food?
Correct Answer
A. Calorie
Explanation
The unit used to express the amount of energy in food is a calorie. A calorie is a unit of energy and is commonly used to measure the energy content of food and beverages. It represents the amount of heat required to raise the temperature of one gram of water by one degree Celsius.
8.
The drawing below represents a pair of chromosomes. The area labeled “bands” shows the location of
Correct Answer
D. Specific genes
Explanation
The drawing of the chromosomes shows the location of "bands," which are specific regions on the chromosomes. These bands are known to contain specific genes. Therefore, the correct answer is that the area labeled "bands" represents the location of specific genes.
9.
Many cars today are designed to get better gas mileage than those made in the past. This change resulted from a need to
Correct Answer
D. Conserve resources
Explanation
Cars today are designed to get better gas mileage than those made in the past in order to conserve resources. By improving fuel efficiency, cars can use less gasoline and reduce the overall consumption of natural resources. This helps to minimize the depletion of non-renewable resources and reduce the environmental impact of transportation.
10.
A scientist crosses two different varieties of corn to produce a single variety that has traits from both parents. This technique is an example of
Correct Answer
C. Selective breeding
Explanation
The process described in the question, where a scientist crosses two different varieties of corn to create a new variety with desired traits, is known as selective breeding. Selective breeding is a technique used by humans to intentionally breed plants or animals with specific traits to produce offspring with those desired traits. This process allows for the selection and combination of desirable traits from different parent organisms, resulting in a single variety that inherits traits from both parents.
11.
What is the nutrient source for some fungi?
Correct Answer
D. Dead organisms
Explanation
Some fungi obtain their nutrients from dead organisms. Fungi are decomposers and play a vital role in breaking down organic matter, such as dead plants and animals. They secrete enzymes that break down complex organic molecules into simpler forms, which they can then absorb and use as a source of energy and nutrients. This process of decomposition helps to recycle nutrients back into the ecosystem and is essential for maintaining the balance of ecosystems.
12.
Which event is the best example of competition between species in a pond environment?
Correct Answer
B. Frogs and toads eating flies
Explanation
Frogs and toads eating flies is the best example of competition between species in a pond environment because both frogs and toads rely on flies as a food source. They compete for the same prey, which creates competition for resources and survival. This interaction demonstrates the competition for food and the struggle for survival between different species in the pond ecosystem.
13.
The diagram below shows a cross section of a bean seed.
Embryo
Seed coat
X
The function of part X in the bean seed is to
Correct Answer
B. Provide nutrients for the embryo
Explanation
Part X in the bean seed is responsible for providing nutrients for the embryo. This is because the embryo, which is the developing plant, requires nutrients to grow and develop into a mature plant. Part X, therefore, plays a crucial role in ensuring the embryo's nourishment and overall development.
14.
Grasses, shrubs, and trees are called producers because they make
Correct Answer
D. Food
Explanation
Grasses, shrubs, and trees are called producers because they make food through the process of photosynthesis. They use sunlight, water, and carbon dioxide to produce glucose, which is a form of food for themselves and other organisms in the ecosystem. This process is essential for the survival of these plants and also provides energy for the entire food chain.
15.
A broken bone heals through the process of
Correct Answer
C. Cell division
Explanation
When a bone is broken, the healing process involves cell division. Cell division allows new cells to be produced, which then form a callus around the broken bone. This callus eventually hardens and becomes new bone tissue, leading to the healing of the broken bone. Adaptation refers to the process of adjusting to a new environment or situation, and mutation refers to a change in the DNA sequence. Chemical digestion is the process of breaking down food molecules in the body.
16.
Which substance do all living things require to survive?
Correct Answer
B. water
Explanation
Water is essential for all living things to survive. It plays a crucial role in various biological processes such as digestion, circulation, and temperature regulation. Water is a universal solvent that helps in the transportation of nutrients and removal of waste products from cells. It is also involved in chemical reactions within the body and helps maintain the structure and function of cells and tissues. Without water, living organisms would not be able to carry out vital functions and would eventually die.
17.
What advantage does a species that reproduces sexually have over a species that reproduces asexually?
Correct Answer
A. There is greater variation among the offspring.
Explanation
A species that reproduces sexually has an advantage over a species that reproduces asexually because there is greater variation among the offspring. Sexual reproduction involves the fusion of gametes from two parents, resulting in genetic recombination and the creation of unique combinations of genes in each offspring. This genetic diversity allows for adaptation to changing environments and increases the chances of survival for the species. In contrast, asexual reproduction produces offspring that are identical to the parent, limiting genetic variation and potentially making the species more vulnerable to environmental changes.
18.
What are produced in both the male and female reproductive systems in humans?
Correct Answer
D. Fertilized eggs
Explanation
In both the male and female reproductive systems in humans, sperm is produced in the male reproductive system, while fertilized eggs are produced in the female reproductive system. Nutrients are not specifically produced in the reproductive systems, and the option "fertilized eggs" is repeated in the answer choices.
19.
Which life process is shown by the equation below? oxygen + food carbon dioxide + water + energy enzymes
Correct Answer
D. Respiration
Explanation
The equation given represents the process of respiration. Respiration is a life process in which oxygen is taken in by an organism and combined with food to produce carbon dioxide, water, and energy. This process occurs in cells and is essential for the release of energy needed for various activities and functions within the organism.
20.
Which diagram below represents one type of human tissue? (The diagrams are not drawn to scale.)
Correct Answer
B. Muscle
Explanation
The correct answer is Muscle because muscle tissue is responsible for movement in the human body. The diagram represents a bundle of muscle fibers, which are long and cylindrical in shape. The striations on the fibers indicate that it is skeletal muscle tissue, which is attached to bones and allows for voluntary movement.
21.
Which process is shown in the diagram below?
Correct Answer
D. MetamorpHosis
Explanation
The diagram likely shows the process of metamorphosis because it involves a transformation or change in form. This process is commonly seen in organisms such as insects, amphibians, and some marine animals, where they undergo distinct stages of development, such as from a larva to an adult.
22.
The diagram below shows a food web for a community. Which organisms in the diagram are carnivores?
Correct Answer
D. Grasshoppers and mice
Explanation
Carnivores are organisms that primarily consume other animals. In the given food web diagram, grasshoppers and mice are the only organisms that feed on other animals. Grasshoppers are known to consume smaller insects, while mice are known to feed on insects, small birds, and other small animals. Therefore, grasshoppers and mice are the carnivores in this food web.
23.
The diagram below shows a material being cycled between the living and nonliving environments. Which material is being cycled?
Correct Answer
C. Oxygen
Explanation
The diagram shows a material being cycled between the living and nonliving environments. Oxygen is being cycled as it is used by living organisms during respiration and released back into the environment during photosynthesis.
24.
Which information would probably be most helpful to someone trying to identify a mineral sample?
Correct Answer
C. Hardness and streak of the sample
Explanation
To identify a mineral sample, information about its hardness and streak would be most helpful. Hardness refers to the resistance of a mineral to scratching, and different minerals have different hardness levels. Streak refers to the color of the powdered form of a mineral when it is scraped across a surface, which can also vary between minerals. By knowing the hardness and streak of a sample, one can compare it to known mineral properties and narrow down the possibilities for identification. The location, mass, shape, texture, color, and size of the sample may provide additional clues, but hardness and streak are key factors in mineral identification.
25.
In which type of rock is the fossil imprint of a fern leaf most likely to be found?
Correct Answer
C. Sedimentary
Explanation
Fossil imprints of fern leaves are most likely to be found in sedimentary rock. Sedimentary rocks are formed from the accumulation and compaction of sediment, such as sand, mud, and organic material, over time. Fossils are often preserved in sedimentary rocks because the layers of sediment can act as a protective barrier, preventing decay and allowing for the preservation of delicate structures like fern leaves. Igneous and metamorphic rocks are formed through different processes and are less likely to contain fossil imprints. Volcanic rocks, while technically igneous, are not specifically known for preserving fossils.
26.
Studies of earthquake waves have helped scientists determine the
Correct Answer
A. Structure of Earth’s interior
Explanation
By studying earthquake waves, scientists can analyze how these waves travel through different layers of the Earth. The behavior of these waves, such as their speed and direction, provides valuable information about the composition and structure of the Earth's interior. This helps scientists understand the different layers of the Earth, including the crust, mantle, and core, as well as their properties and boundaries. Therefore, studying earthquake waves is crucial in determining the structure of Earth's interior.
27.
An object accelerates at 3 meters per second2 when a 10-newton (N) force is applied to it. Which force would cause this object to accelerate at 6 meters per second2?
Correct Answer
C. 20 N
Explanation
The force required to cause an object to accelerate is directly proportional to the acceleration. In this case, the object accelerates at 3 meters per second^2 when a 10 N force is applied. To double the acceleration to 6 meters per second^2, the force should also be doubled. Therefore, the force required would be 20 N.
28.
Which statement would most likely be included in a news report about an approaching hurricane?
Correct Answer
C. Evacuate low-lying areas near the coast.
Explanation
This statement would most likely be included in a news report about an approaching hurricane because it advises people to take necessary precautions and move to safer areas to avoid potential dangers and damages caused by the hurricane.
29.
The surface of Earth is covered mostly by
Correct Answer
D. Water
Explanation
The surface of Earth is covered mostly by water. This is supported by the fact that approximately 71% of Earth's surface is covered by oceans, seas, and other bodies of water. Water is essential for supporting life and plays a crucial role in various Earth processes such as weather patterns, climate regulation, and the water cycle. While solid rock and molten rock (magma) do exist on Earth's surface in the form of landmasses and volcanoes, they are not as widespread as water. Ice, although present in polar regions and high-altitude areas, is also not as abundant as water on the Earth's surface.
30.
Part of the east coast of South America and the west coast of Africa have matching fossils within the same series of rock layers. This provides evidence that these two continents were once
Correct Answer
B. Joined together as one landmass
Explanation
The presence of matching fossils in the rock layers of the east coast of South America and the west coast of Africa suggests that these two continents were once joined together as one landmass. This is because the fossils found in these regions would have been able to migrate and spread across the landmass when it was connected. If the continents were separated by a larger ocean, located near the North Pole, or in different hemispheres, it would be unlikely for the same fossils to be found in both regions. Therefore, the most plausible explanation is that the continents were once joined together.
31.
The diagram below shows a rock suspended above an overflow container filled with water up to the overflow spout. A graduated cylinder is positioned next to the container to collect water that comes out of the overflow spout.
Which property of the rock can be directly determined when the rock is placed in the overflow container?
Correct Answer
C. Volume
Explanation
When the rock is placed in the overflow container, the property that can be directly determined is its volume. This is because the water that overflows from the container into the graduated cylinder will displace an amount of water equal to the volume of the rock. By measuring the volume of water collected in the graduated cylinder, we can determine the volume of the rock.
32.
A sudden change in the weather at a certain location is most likely caused by
Correct Answer
A. The arrival of an air mass
Explanation
A sudden change in the weather at a certain location is most likely caused by the arrival of an air mass. Air masses are large bodies of air with consistent temperature and humidity characteristics. When a new air mass moves into an area, it can bring different weather conditions, such as changes in temperature, humidity, wind direction, and precipitation. This can result in a sudden change in the weather at that location. Severe earthquakes, high ocean tides, and eclipses of the Moon do not directly impact the weather and are unlikely to cause sudden weather changes.
33.
Which process is an example of a physical change?
Correct Answer
D. Milk souring
Explanation
Milk souring is an example of a physical change because it involves a change in the physical properties of the milk without altering its chemical composition. When milk sours, it undergoes a change in taste, texture, and smell due to the growth of bacteria, but the molecules that make up the milk remain the same. This is different from a chemical change, where the composition of the substance is altered. In the other options, wood burning, iron rusting, and ice melting, chemical reactions occur, resulting in the formation of new substances with different properties.
34.
The graph below shows the heating curve for substance X.
At approximately which temperature does a phase change begin? Substance X
Correct Answer
B. -10°C
Explanation
The phase change begins at approximately -10°C because the graph shows a sudden change in the slope of the curve at that temperature. This indicates a change in the state of the substance, which is characteristic of a phase change.
35.
Which example best demonstrates the process of conduction?
Correct Answer
C. A metal spoon gets warm when used to stir
hot soup.
Explanation
The process of conduction involves the transfer of heat through direct contact between objects. In this example, the metal spoon gets warm when it is used to stir hot soup because the heat from the soup is conducted through the spoon. The other examples do not involve the transfer of heat through direct contact, so they do not demonstrate the process of conduction.
36.
All matter is made up of
Correct Answer
B. Atoms
Explanation
Atoms are the smallest unit of matter that retains the properties of an element. All matter, including cells, molecules, and compounds, are composed of atoms. Cells are the basic structural and functional units of living organisms, but they are made up of various types of molecules, which in turn are made up of atoms. Therefore, atoms are the fundamental building blocks of all matter.
37.
The diagram below shows water being heated in a flask. The flask has a rubber stopper with a glass tube extending through it. The current level of the water in the glass tube is indicated. The temperature of the water is 25°C. If heating continues, the water in the glass tube will most likely
Correct Answer
D. Rise higher in the tube
Explanation
As the water in the flask is being heated, it will start to expand and become less dense. This decrease in density will cause the water in the glass tube to rise higher as it displaces the denser, colder water in the tube. Therefore, the correct answer is that the water will rise higher in the tube.
38.
The diagram below shows a metal spoon in a glass of water.
Which process causes the metal spoon to appear split or broken?
Correct Answer
B. Refraction
Explanation
Refraction is the process that causes the metal spoon to appear split or broken when placed in a glass of water. Refraction occurs when light passes from one medium to another with a different refractive index, causing the light rays to change direction. In this case, when light from the spoon enters the water, it bends or refracts due to the change in the medium's refractive index, creating the illusion of a split or broken spoon.
39.
The diagram below shows a model of a sample of gas particles at room temperature.
Which diagram best shows the results of removing heat from this sample until it freezes?
Correct Answer
B. B
Explanation
Diagram b best shows the results of removing heat from the sample until it freezes because it shows the gas particles slowing down and coming closer together, indicating a decrease in temperature. The particles in diagram b are arranged in a more ordered and structured pattern, suggesting that the gas has transformed into a solid state, which is characteristic of freezing.
40.
The diagram below shows a spinning water sprinkler. Water comes through a hose and is sprayed by the sprinkler. Which principle best explains why the sprinkler spins?
Correct Answer
A. Every action has an equal and opposite
reaction.
Explanation
The principle of "Every action has an equal and opposite reaction" best explains why the sprinkler spins. When water is sprayed out of the sprinkler, it exerts a force in one direction. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. So, the force exerted by the water in one direction causes the sprinkler to spin in the opposite direction.
41.
The gravitational force between the Moon and Earth depends on
Correct Answer
C. Their masses and how far apart they are
Explanation
The gravitational force between the Moon and Earth depends on their masses because the greater the mass of an object, the greater its gravitational force. Additionally, the force also depends on how far apart the Moon and Earth are because the force of gravity weakens as the distance between objects increases. Therefore, both the masses of the Moon and Earth and the distance between them determine the strength of the gravitational force between them.
42.
The diagram below shows a hammer being used by a person to remove a nail from a piece of wood.
The hammer is being used as which type of simple machine?
Correct Answer
C. Lever
Explanation
The diagram shows a person using a hammer to remove a nail from a piece of wood. A lever is a simple machine that consists of a rigid bar that pivots on a fixed point called a fulcrum. In this case, the person is applying force on one end of the hammer handle, while the other end of the handle is pivoting around the fulcrum, allowing the nail to be pulled out of the wood. Therefore, the hammer is being used as a lever.
43.
The data table below shows changes in four different measurements as a human develops from birth to adulthood. Each measurement is expressed as a percentage of the adult value.
According to the table, which measurement shows the greatest percentage increase from birth to age 5?
Correct Answer
A. Brain weight
Explanation
The correct answer is brain weight. This can be determined by comparing the percentage increase for each measurement from birth to age 5. Since the question asks for the greatest percentage increase, we need to look for the measurement that has the largest difference between the percentage at birth and the percentage at age 5.
44.
The diagram below shows the orbit of Halley’s Comet around the Sun as viewed from space. Earth’s orbit is also shown.
The only years shown in which Halley’s Comet could be viewed from Earth without the use of a telescope were 1910 and 1986. What is the next year in which Halley’s Comet will be visible from the Earth without the use of a telescope?
Correct Answer
B. 2062
Explanation
Halley's Comet has an orbital period of approximately 76 years. The previous visible appearances of the comet were in 1910 and 1986. To determine the next visible year without a telescope, we add 76 years to the previous appearance in 1986. This gives us the year 2062, which is the next time Halley's Comet will be visible from Earth without the use of a telescope.