This is Part-4 of our free GED test answers for Science. Topics included in this review material are Life Science, Physical Science, Earth and Space Science, and Science Practices. The exam is designed to assess your ability to read, understand, and apply scientific concepts and principles.
GED is an important test that requires preparation. Since it is a computer-based exam, the test questions are scrambled to protect its integrity. We recommend knowing more about the exam and learn key strategies that’ll help you make big improvements during the actual tests.
GED Ready Science reviewer, pt. 4
Question 1. All of the following are primates EXCEPT
Question 2. Which of the following statements about the structure of DNA is true?
A. DNA is a single-stranded molecule.
B. The four nucleotide bases found in DNA are adenine, guanine, cytosine, and uracil.
C. DNA is only found in eukaryotic cells.
D. Adenine always pairs with thymine, while guanine always pairs with cytosine.✅
Question 3. People wear woolen gloves in the winter because gloves?
A. increase the temperature of cold air through convection.
B. increase the amount of heat energy generated by the body through conduction.
C. generate heat energy through radiation.
D. decrease the loss of body heat to surroundings through insulation.✅
Question 4. Ice floats on water because
A. ice has a lower temperature.
B. ice is less dense than water✅
C. it needs energy from the sun to melt.
D. water conducts heat better than ice
Read the passage below and answer questions 5–7.
An island in the Adriatic Sea was overpopulated with snakes. Sailors who came to the island brought and let loose mongoose, animals that feed on snakes. The population of snakes started decreasing since the mongooses were eating them. The mongoose population started increasing since there was ample food around. The mongooses were not native to the island and there was no predator on the island to keep the mongoose population in check. At some point, there were hardly any snakes left on the island, and people started populating it. The mongoose, facing a shortage of snakes, started eating chickens that people kept for their eggs and meat. However, people caught on and protected the chickens from getting eaten. The mongoose population decreased. Some remain on the island, but their number is now at equilibrium, kept in check by the availability of food.
Question 5. There were hardly any snakes left on the island because
A. mongooses had eaten them.✅
B. there was no predator for the mongooses.
C. sailors brought them prey
D. people had killed them.
Question 6. The passage illustrates
A. the fragility of an ecosystem.
B. the relationship between the population of predator and prey.
C. the interdependence of organisms.
D. all of the above✅
Question 7. Which statement best describes the change in the population of mongooses on the island?
A. The population was small before sailors brought more mongooses, increasing the gene pool. The number of mongooses kept growing until the people started protecting the chickens.
B. The population was zero before sailors brought a few. The few then multiplied, and the number of mongooses on the island is still steadily growing.
C. The population was zero before sailors brought a few. The few then multiplied, increasing the number of mongooses. When the snakes were almost gone, the mongoose population started decreasing.✅
D. The population was initially large, but when a predator was brought by sailors, the number of mongooses decreased.
Question 8. Most bacteria cannot grow in high concentrations of salt. As a result,
A. most antibiotics are sweet.
B. Utah’s Great Salt Lake is filled with bacteria.
C. there are no bacteria in fresh water.
D. salt acts as a preservative in ham, beef jerky, and other salty foods.✅
For questions 9 and 10 refer to the passage provided below.
In 1628, English physician William Harvey established that blood circulates throughout the body. He recognized that the heart acts as a pump and does not work by using up blood as earlier anatomists thought. To carefully observe the beating of the heart and the direction of blood flow, Harvey needed to see the works of the blood in slow motion. Since there was no way for him to observe a human heart in slow motion, he studied the hearts of toads and snakes, rather than the rapidly beating hearts of “warm-blooded” mammals and birds. By keeping these animals cool, he could slow their hearts down. The main argument for his conclusion that the blood circulates stemmed from his measurement of the amount of blood pumped with each heartbeat. He calculated that the amount of blood pumped each hour by far exceeds the total amount of blood in the body and proved that the same blood passes through the heart over and over again.
Question 9. Which of the following did Harvey do?
I. Observe the heartbeat and blood flow in snakes and frogs.
II. Determine that the heart acts as a pump.
III. Count the number of blood cells that pass through the heart every hour.
IV. Show that the blood circulates.
A. He did I and II.
B. He did I, II, and IV.
C. He did I, III, and IV.✅
D. He did II, III, and IV.
Question 10. What misconception did scientists harbor before Harvey’s study?
A. The heart pumps blood.
B. The heart uses up blood.✅
C. The heart contains no blood.
D. The heart circulates blood.
Question 11. Two negatively charged spheres
A. repel each other.✅
B. attract each other.
C. neither attract nor repel each other.
D. attract each other only when the distance between them is small.
Question 12. Which of the following is NOT true?
A. All organisms have a cell wall.✅
B. All organisms have genetic material.
C. All organisms are made of one or more cells.
D. All organisms are made of atoms.
Question 13. Which of the following is NOT true about sunlight?
A. It can be absorbed by plants.
B. It is a form of radiation.
C. Its speed is infinite.✅
D. It contains the colors of the rainbow.
Question 14. In humans, a pair of chromosomes (one from each parent) determines the sex of the baby. Females have two X chromosomes, while males have an X and a Y chromosome. The baby always gets an X chromosome from the mother, so in humans, the father determines the sex of the baby by supplying it with either an X chromosome to make it female, or a Y chromosome to make it male. In birds, like in humans, a pair of chromosomes determines the sex. Birds with two W chromosomes are male. Birds with a W chromosome and a Z chromosome are female. Which statement is true about birds?
A. The male bird determines the sex of the offspring by supplying it with the X or the Y chromosome.
B. The female bird determines the sex of the offspring by supplying it with the W or the Z chromosome.✅
C. The male bird determines the sex of the offspring by supplying it with the W or the Z chromosome.
D. The male bird determines the sex of the offspring by supplying it with one of its W chromosomes
Question 15. In order to protect themselves from being eaten, animals resort to camouflage and chemical defense. Animals camouflage by mimicking the appearance of their environment. Animals that have chemical defenses contain chemicals noxious to predators. Which of these is NOT an example of camouflage or chemical defense?
A. Roses have thorns.✅
B. A skunk has an awful smell.
C. A walking stick insect looks just like a twig.
D. Feathers of the pitohui bird in New Guinea contain a deadly toxin.
Question 16. All of the following are mammals EXCEPT
Question 17. Which statement about energy and/or matter is incorrect?
A. Heat energy is composed of heat atoms.✅
B. Matter and energy can’t be created.
C. Matter and energy can’t be destroyed.
D. All matter tends toward more disordered states.
Question 18. Change of phase is a process whereby matter changes form (solid, liquid, gas). Which one of the following constitutes a phase change?
C. digestion of food
D. condensation of water vapor✅
As the pressure of a gas increases at a constant temperature, the volume of the gas decreases.
Question 19. If you were a diver and you wanted to take an oxygen tank with you, what would you do?
A. Increase the temperature of oxygen in the tank, so that the cold oxygen doesn’t damage the lungs.
B. Pressurize the oxygen, so more of it can fit in a tank of a manageable size.✅
C. Increase the temperature of the oxygen and decrease the pressure, so the volume stays the same.
D. Decrease the temperature of oxygen, so that it doesn’t escape from the tank.
Question 20. There are four blood types in humans: A, B, AB, and O. An individual with blood type A has antibodies for B, so he or she can’t receive type B blood. Similarly, a person with blood type B has antibodies for type A and can’t receive type A blood. A person with AB blood type has no antibodies and can receive blood from anyone. A person with type O blood has both A and B antibodies and can receive blood only from someone else with type O blood. Based on this information, someone with type B blood can donate to
A. blood groups B and O
B. blood groups B and AB✅
C. only blood group B
D. only blood group AB
Question 21. The boiling point in hydrocarbons (molecules containing H and C) increases with increasing molecular weight due to larger intermolecular forces. Which of these hydrocarbons would you expect to have the highest boiling point?
A. Option A
B. Option B
C. Option C
D. Option D
E Option E✅
Question 22. In the early 19th century, almost all peppered moths collected by biologists in the U.K. were pale and mottled. Only rarely was a collector able to find a dark-peppered moth. After the Industrial Revolution, when furnaces filled the air with dark soot, the light-peppered moth became rare and the dark-peppered moth was most common in industrial cities. A reasonable explanation for this change is that the dark moth was less likely to be seen and eaten by birds against the dark background. This explanation illustrates the principle of
A. gene flow.
B. male competition.
C. natural selection.✅
D. male competition.
Question 23. According to Newton’s laws of motion, an object set in motion remains in motion unless a force acts on it. If you suspend an object from a string and make it swing, the object will swing for a while, then slow down and stop. Why does the suspended object stop swinging?
A. because the energy of motion is converted to heat through friction with air✅
B. because the mass of the object is too small to maintain the motion
C. because an object at rest remains at rest unless a force acts upon it
D. because gravity is pulling it toward the Earth
Different colors of light correspond to different wavelengths. Wavelengths are often quoted in nanometers (nm). The wavelengths of the visible part of the spectrum are shown in the diagram below.
Question 24. According to the diagram, blue-green light would most likely have a wavelength of
A. 350 nm
B. 670 nm.
C. 470 nm.✅
D. 550 nm.
Question 25. Two main chemicals are responsible for the communication of the brain with the organs you have no conscious control over (heart, digestive system, endocrine system). The chemical norepinephrine helps your body get ready for a fight-or-flight action by stirring up energy stores. In contrast, the chemical acetylcholine helps conserve energy by slowing the heart and increasing intestinal absorption. Which of the following situations is least likely to lead to increased levels of norepinephrine?
A. taking an important exam
B. running away from someone holding a knife
C. going on a first date with someone
D. petting a rabbit✅
Question 26. What always stays the same when a chemical reaction takes place?
A. the amount of gas
B. the number of atoms✅
C. the amount of solid matter
D. the number of molecules
Question 27. Which of the following is NOT true about gravity?
A. People can jump higher on the moon than on Earth because the gravitational force between a person and the moon is lower than the gravitational force between a person and the Earth.
B. Gravitational force between two objects depends on the distance between them.
C. Gravitational force between two objects depends only on the mass of the larger object.✅
D. The more massive two objects are, the greater the gravitational force between them.
A woman is most likely to get pregnant if she has unprotected sex a few days before and on the day of ovulation when the egg is released from the ovaries. The release of the egg is hormonally stimulated, meaning that a hormone in the woman’s body triggers ovulation. On average, women ovulate around the 14th day of their menstrual cycle. The following is a graph showing the levels of three hormones throughout the menstrual cycle of an average woman.
Question 28. Based on the graph, which hormone is most directly responsible for triggering ovulation?
Question 29. In an exothermic process, heat is released by the process to the surroundings. An example of an exothermic process is burning wood. An endothermic process requires the input of heat from the surroundings. An example of an endothermic process is boiling water. Which of the following is an endothermic process?
A. detonation of an explosive
B. melting ice✅
C. burning paper
D. the formation of helium on the sun
In peas, the gene for green color is dominant over the gene for yellow color. We will specify the gene for yellow peas as y, and the gene for green peas as Y. Each pea has two genes for color (one from each parent) and donates only one gene for color to its offspring. Yellow peas have the genotype yy. Any other genotype leads to green peas. Consider the following Punnett square:
Question 30. The offspring of these two parents
A. could be yellow-green.
B. could never be green.
C. could never be yellow.
D. could be either green or yellow.✅
Question 31. A species may live in association with another species. Such an arrangement is called symbiosis. Symbiosis in which both species benefit is called mutualism. If the symbiosis is beneficial to one species and neither beneficial nor harmful to the other, it is called commensalism. If one species benefits at the expense of the other, the relationship is called parasitism. A tick that attaches to the skin of a human or animal and feeds on its blood is an example of
Question 32. Osmosis is the movement of water across a selectively permeable membrane in order to equalize the concentration (the amount of protein per milliliter of water) on two sides of the membrane. Consider the diagram below. The container is divided into two compartments, A and B, by a selectively permeable membrane. Each circle represents 100 protein molecules that can’t pass through the membrane. The amount of water on two sides of the membrane is initially equal. What will happen as a result of osmosis?
A. Water will flow from compartment B to compartment A.
B. Protein will flow from compartment A to compartment B.
C. Water will flow from compartment A to compartment B.✅
D. Protein will flow from compartment A to compartment B.
In an acid-base reaction, an acid reacts with a base to produce water and salt. The pH scale can be used to describe the acidity of a liquid. Look at the diagram below.
Question 33. Which two liquids could undergo an acid-base reaction?
A. stomach acid and beer
B. blood and saliva
C. bleach and ammonia
D. bleach and vinegar✅
Question 34. Identical twins have exactly the same genes. Identical twins result when
A. the same sperm cell fertilizes two eggs.
B. an egg fertilized by one sperm divides in two.✅
C. the same egg is fertilized by two sperm cells.
D. two eggs are fertilized with two sperm cells.
Question 35. The amount of solute that can be dissolved in a solvent at a given temperature is called solubility. For most substances, solubility increases with temperature. Rock candy can be made from sugar solutions that have an excess of sugar dissolved. The amount of sugar per 100 grams of water at a given temperature has to be higher than the amount that is normally soluble in order to make rock candy. Based on the solubility of sugar in water as a function of temperature, plotted in the graph, how much sugar would you need to dissolve in 100 grams of water to make rock candy at 40° C?
A. more than 250 grams✅
B. less than 50 grams
C. between 50 and 100 grams
D.150 and 200 grams