GED Science Test #8 3 — Questions and Answers
Question 1: Which describes the role of ribosomes in a cell?
- Synthesizing proteins from amino acids (Correct answer)
- Producing energy via cellular respiration
- Transporting materials within the cell
- Controlling what enters and exits the cell
Correct answer: Synthesizing proteins from amino acids
Ribosomes are the sites of protein synthesis. They read mRNA sequences and assemble amino acids in the correct order to build proteins. Ribosomes can be free in the cytoplasm or attached to the rough ER.
Question 2: What does the term "biodiversity" refer to?
- The variety of species and genetic diversity within an ecosystem (Correct answer)
- The total number of organisms in a habitat
- The range of temperatures in an environment
- The number of food chains in an ecosystem
Correct answer: The variety of species and genetic diversity within an ecosystem
Biodiversity refers to the variety of life forms — including species diversity, genetic diversity, and ecosystem diversity. High biodiversity generally increases ecosystem stability and resilience.
Question 3: A catalyst in a chemical reaction:
- Speeds up the reaction without being consumed (Correct answer)
- Is consumed and must be replaced
- Slows down the reaction
- Changes the products of the reaction
Correct answer: Speeds up the reaction without being consumed
A catalyst lowers the activation energy of a reaction, speeding it up, but is not consumed in the process. Enzymes are biological catalysts that control metabolism in living organisms.
Question 4: The diagram shows a wave with a wavelength of 4 m and 2 complete cycles occurring per second. What is the wave's speed?
- 8 m/s (Correct answer)
- 2 m/s
- 4 m/s
- 0.5 m/s
Correct answer: 8 m/s
Wave speed = wavelength × frequency = 4 m × 2 Hz = 8 m/s. The frequency is 2 cycles per second (2 Hz), and the wavelength is 4 m.
Question 5: Which of the following human activities most directly contributes to the loss of biodiversity?
- Habitat destruction and deforestation (Correct answer)
- Tidal energy generation
- Solar panel installation
- Using electric vehicles
Correct answer: Habitat destruction and deforestation
Habitat destruction is the leading cause of biodiversity loss. When natural habitats are cleared for agriculture, development, or logging, species lose their homes and food sources, often leading to extinction.
Question 6: A chemical equation is balanced when:
- The number of atoms of each element is the same on both sides
- The total mass of reactants equals the total mass of products
- The number of molecules is the same on both sides
- Both A and B are correct (Correct answer)
Correct answer: Both A and B are correct
A balanced chemical equation satisfies the Law of Conservation of Mass: atoms are neither created nor destroyed. This means both the number of atoms AND the total mass must be equal on both sides of the equation.
GED Science Test #8 3
Which describes the role of ribosomes in a cell?