input: OPTIONS:
- chlorophyll
- enzymes
- cytoplasmic acid
- salicylic acid Now, answer this question: Answer the following question given this paragraph: Plants don't have immune systems, but they do respond to disease. Typically, their first line of defense is the death of cells surrounding infected tissue. This prevents the infection from spreading. Many plants also produce hormones and toxins to fight pathogens. For example, willow trees produce salicylic acid to kill bacteria. The same compound is used in many acne products for the same reason. Exciting new research suggests that plants may even produce chemicals that warn other plants of threats to their health, allowing the plants to prepare for their own defense. As these and other responses show, plants may be rooted in place, but they are far from helpless. Q: What do willow trees produce to kill bacteria? A:
A:
output: salicylic acid

Answer the following question given this paragraph: Like many other animals, sheep travel in herds. The tendency is for each individual sheep to stay with the herd. However, a sheep may sometimes wander off, depending on how strong the attraction is for a particular food or water supply. At other times, a sheep may become frightened and run off. Whether a sheep chooses to stay with the herd or go its own way depends on the balance between attraction to the herd and attraction to the outside influence. Q: What is the collective travel of sheep known as? A:

OPTIONS:
- gaggle
- load
- den
- herd

Answer: herd

Problem: OPTIONS:
- membrane
- muscle
- fiber
- cartilage
Q: Answer the following question given this paragraph: Another distinguishing feature of vertebrates is an endoskeleton made of bone or cartilage. Cartilage is a tough tissue that contains a protein called collagen. Bone is a hard tissue that consists of a collagen matrix, or framework, filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. An endoskeleton made of bone rather than cartilage allows animals to grow larger and heavier. Bone also provides more protection for soft tissues and internal organs. Q: What is the tough tissue that contains collagen? A:
Answer: cartilage

Problem:OPTIONS:
- effective variable
- essential variable
- independent variable
- dependent variable

Answer the following question given this paragraph: An experiment generally tests how one variable is affected by another. The affected variable is called the dependent variable . In the plant experiment shown in the Figure above , the dependent variable is plant growth. The variable that affects the dependent variable is called the independent variable . In the plant experiment, the independent variable is fertilizersome plants will get fertilizer, others will not. In any experiment, other factors that might affect the dependent variable must be controlled. In the plant experiment, what factors do you think should be controlled? ( Hint: What other factors might affect plant growth?). Q: In a scientific experiment, the variable that is affected by the other one is called what? A:
****
A: dependent variable

Answer the following question given this paragraph: Droughts also depend on what is normal for a region. A region that gets significantly less precipitation than normal for an extended period of time is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Q: What term is used to describe a region getting significantly less precipitation than normal for an extended period of time? A:
OPTIONS:
- dog days
- doldrums
- flood
- drought
drought

Answer the following question given this paragraph: The body's first line of defense consists of different types of barriers that keep most pathogens out of the body. Pathogens are disease-causing agents, such as bacteria and viruses. These and other types of pathogens are described in Figure below . Regardless of the type of pathogen, however, the first line of defense is always the same. Q: What is the term for disease-causing agents, such as bacteria and viruses? A:
OPTIONS:
- spores
- parasites
- vaccines
- pathogens

Answer:
pathogens