REMEDIATION FOR GR08_SCI_67R_BodiesOfKnowledgeReviewA_FY25

Henry is feeling unwell and visits the doctor. The doctor explains how different types of infectious agents respond to the use of antibiotics. How do they respond?

• Viruses respond to antibiotics; bacteria do not.

• Bacteria respond to antibiotics; viruses do not.

• Both bacteria and viruses respond to antibiotics.

• Neither bacteria nor viruses respond to antibiotics.

Answer explanation

Bacteria are susceptible to antibiotics, which can kill or inhibit their growth. In contrast, viruses lack the cellular structure that antibiotics target, making them ineffective against viral infections.

How does the chemical composition of the stratosphere work to protect life on Earth?

• The gases in the stratosphere absorb some of the harmful rays from the Sun.

• The stratosphere produces oxygen from carbon dioxide, keeping the gases most important for life in balance.

• The chemicals in the stratosphere repel oxygen and carbon dioxide so that the gases most important to living organisms are kept at the surface.

• The chemicals in the stratosphere create clouds that keep the harmful gases in the upper atmosphere away from the living organisms at the surface.

Answer explanation

The correct choice explains that gases in the stratosphere, particularly ozone, absorb harmful ultraviolet rays from the Sun, protecting life on Earth from damage caused by these rays.

Eddie is curious about how the color of a surface influences its ability to absorb heat. He uses three identical metal plates painted white, black, and red, and places them under a heat lamp. A thermometer is attached to each plate to measure the temperature change. What is the independent variable in this experiment?

• Type of thermometer used

• Color of the plates

• Initial temperature of the plates

• Duration of exposure to the heat lamp

Answer explanation

The test variable, or independent variable, in this investigation is the color of the boxes. Eddie is changing the color to see how it affects the temperature inside, making it the factor he is testing.

If the populations are exposed to a new disease that affects both leopards and cheetahs, which statement best explains what would happen in the presence of the new disease?

• Both populations would decrease.

• Only the leopard population would decrease.

• Only the cheetah population would decrease.

• Neither population would be affected.

Answer explanation

The new disease would likely reduce the populations of both leopards and cheetahs, potentially leading to increased competition for resources and affecting their survival rates.

Which statement best explains the relationship between genetic diversity and survival?

• The cheetah population would be less likely to survive because of low genetic diversity.

• The leopard population would be less likely to survive because of high genetic diversity.

• The leopard population would be more likely to survive because of low genetic diversity.

• The cheetah population would be more likely to survive because of high genetic diversity.

Answer explanation

The cheetah population has low genetic diversity, making it less adaptable to environmental changes and diseases, which decreases its chances of survival. High genetic diversity generally enhances survival prospects.

How does a scientific law differ from a theory?

• A law is based on empirical evidence, whereas a theory is an educated guess.

• A law states regular patterns in nature, whereas a theory explains the pattern.

• A law can be changed as new information is obtained, whereas a theory does not change.

• A law is established based on a theory, whereas a theory can be independent of prior knowledge.

Answer explanation

A scientific law describes consistent patterns observed in nature, while a theory provides an explanation for those patterns. This distinction is crucial for understanding how scientific knowledge is structured.

Which of these statements best explains the relationship between chromosomes and DNA?

• DNA is a structure made of cells and is located within chromosomes.

• DNA is a structure made of chromosomes and is located within cells.

• Chromosomes are structures made of DNA and are located within cells.

• Chromosomes are structures made of cells and are located within DNA.

Answer explanation

Chromosomes are structures made of DNA, which carry genetic information. They are found within cells, where they play a crucial role in cell division and inheritance, making this statement the best explanation of their relationship.

7. Amelia places a hot metal rod into a cup of cold water. Which statement describes the heat flow in this situation?

• The cold flows from the water to the metal rod because the water is much colder than the rod.

• The heat flows from the metal rod to the water because heat moves from warmer to cooler objects.

• The cold flows from the water and the metal rod to the surroundings because the surroundings are warmer.

Answer explanation

The correct statement is that heat flows from the water to the ice because heat naturally moves from warmer objects (the water) to cooler ones (the ice), leading to the melting of the ice.

An energy pyramid is a diagram used to show how energy flows through a food web. Which answer lists the categories of organisms from the least amount of energy to the greatest amount of energy in the energy pyramid?

• Primary consumers, secondary consumers, tertiary consumers, producers

• Producers, tertiary consumers, secondary consumers, primary consumers

• Tertiary consumers, secondary consumers, primary consumers, producers

• Producers, primary consumers, secondary consumers, tertiary consumers

Answer explanation

In an energy pyramid, energy decreases as you move up. Producers (plants) have the most energy, followed by primary consumers (herbivores), then secondary consumers (carnivores), and finally tertiary consumers (top predators) at the least.

What effect does the polar jet stream have on weather patterns in the United States during the winter months?

• Areas north of the jet stream experience colder temperatures, while areas south experience milder conditions.

• Areas north of the jet stream experience milder temperatures, while areas south experience colder conditions.

• The jet stream leads to frequent tornadoes in northern regions.

• The jet stream ensures uniform temperatures across the nation.

Answer explanation

The polar jet stream acts as a boundary between cold polar air to the north and warmer air to the south. Therefore, cities north of the jet stream experience colder temperatures, while those to the south are generally warmer.