Answer the following question given this paragraph: Since life began on Earth, there have been several major mass extinctions. If you look closely at the geological time scale, you will find that at least five major mass extinctions have occurred in the past 540 million years. In each mass extinction, over 50% of animal species died. The total number of mass extinctions could be as high as 20. Q: What events, resulting in death of over half of animal species, have occurred on earth at least five times in the past 540 million years? Choices: - mass migrations - microevolutions - spontaneous mutations - mass extinctions A:
mass extinctions
Answer the following question given this paragraph: Ray-finned fish include the majority of living fish species, including goldfish, tuna, salmon, perch, and cod. They have a bony endoskeleton and a swim bladder. Their thin fins consist of webs of skin over flexible bony rays, or spines. The fins lack muscle, so their movements are controlled by muscles in the body wall. You can compare their ray fins with the fleshy fins of lobe-finned fish in Figure below . Q: What type of fish are the majority of living species? Choices: - cartilaginous fish - freshwater fish - lungfish - ray-finned fish A:
ray-finned fish
Q: Answer the following question given this paragraph: Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury pictured above is very shiny. Q: What makes metals shiny? Choices: - light characterization - light energy - light expansion - light reflection A:
A: light reflection
Question: Answer the following question given this paragraph: A variable is a factor that can change over the course of an experiment. Independent variables are factors whose values are controlled by the experimenter to determine its relationship to an observed phenomenon (the dependent variable). Dependent variables change in response to the independent variable. Q: The values of which factors are controlled by the experimenter over the course of an experiment? Choices: - other variables - independent elements - independent approaches - independent variables A:
Answer: independent variables
*Question*
Answer the following question given this paragraph: Has this ever happened to you? You walk across a carpet, reach out to touch a metal doorknob, and get an unpleasant electric shock (see Figure below ). The reason you get a shock is because of moving electric charges. Moving electric charges also create lightning bolts and the electric current that flows through cables and wires. Q: Has this ever happened to you? you walk across a carpet, reach out to touch a metal doorknob, and get an unpleasant electric shock? .the reason you get a shock is because of what? Choices: - sunlight charge - temperature charge - solar charge - electrical charge A:
**Answer**
electrical charge
(Q).
Answer the following question given this paragraph: The sporophyte produces haploid spores. The rhizoid buds to form a mature gametophyte. The zygote is housed in the venter. Figure 25.21 Which of the following statements about the fern life cycle is false? a. Sporangia produce haploid spores. The sporophyte grows from a gametophyte. The sporophyte is diploid and the gametophyte is haploid. Sporangia form on the underside of the gametophyte. Q: In some plants, the sporophyte is diploid, while the gametophyte is what? Choices: - gametes - humanoid - meiosis - haploid A:
(A).
haploid