HW #1

Which statements is a hypothesis for Sarah's rat experiments? a) Gymnodinium catenatum produces saxitoxin. b) Ingested saxitoxin does not affect the survival of rats. c) People who ingest saxitoxin may die. d) Saxitoxin inhibits sodium movement into cells. e) Dinoflagellates are responsible for paralytic shellfish poisoning.

b) Ingested saxitoxin does not affect the survival of rats.

Did the results of Sarah's rat experiments conclusively show that dinoflagellates were responsible for the Paralytic Shellfish Poisoning event in Africa? a) Yes. Her rat experiments clearly showed that saxitoxin was responsible for the deaths of 100 people in Africa. b) No. Her rat experiments showed that saxitoxin caused rats to die but she has not clearly shown that the same thing would happen in people. c) No. The results of the experiment were inconclusive. There was no clear evidence that saxitoxin is deadly to rats or people.

b) No. Her rat experiments showed that saxitoxin caused rats to die but she has not clearly shown that the same thing would happen in people.

Identify the experimental group(s) for the rat experiments described in the Paralytic Shellfish Poisoning Scenario. a) Group A only b) Group B only c) Group C only d) Groups A and B e) Groups A and C f) Groups B and C

d) Groups A and B

What would be a reasonable conclusion based on the results of the rat experiments? a) Since dinoflagellates make saxitoxin, shellfish contaminated by dinoflagellates are responsible for paralytic shellfish poisoning. b) There is no connection between eating saxitoxin and survival of rats. c) People who ingest large amounts of saxitoxin will die. d) Rats that eat more saxitoxin have a higher chance of dying. e) The results of the experiment were inconclusive. No conclusion can be made.

d) Rats that eat more saxitoxin have a higher chance of dying.

An experiment that tests only one factor at a time by using a comparison of a control group and an experimental group is? a) an independent variable b) a dependent variable c) a theory d) a controlled experiment

d) a controlled experiment

A series of steps designed to help you solve problems and answer questions while reducing the influence of personal preconceived ideas a) conclusion b) experiment c) prediction d) scientific method

d) scientific method

What is the correct order of steps in the scientific method?• (1) Analyze the results• (2) Ask a question• (3) Communicate results• (4) Draw conclusions• (5) Make a hypothesis• (6) Test the hypothesis

2, 5, 6, 1, 4, 3

What skill is a scientist using when she listens to the sounds that whales make? a) making observations b) drawing conclusions c) making a hypothesis d) interpreting data

a) making observations

A scientist conducted an experiment to determine how the amount of salt in a body of water affects the number of plants that can live in the water. In this experiment, the independent variable is a) the amount of salt in the water b) the number of plants in the water c) the temperature of the water d) the water

a) the amount of salt in the water

When you decide whether or not the data supports the original hypothesis, a) you are drawing a conclusion b) you are making a prediction c) you are forming a hypothesis d) you are asking questions

a) you are drawing a conclusion

In an experiment, the factor that we measure is called the a) controlled variable b) dependent variable c) independent variable

b) dependent variable

In science, an educated guess is called a/an a) conclusion b) hypothesis c) observation d) prediction e) question

b) hypothesis

A scientist hypothesizes that the temperature at which an alligator's egg is incubated will determine whether the alligator offspring will be male or female. The dependent variable is a) the alligator b) the gender of the alligator offspring c) the temperature

b) the gender of the alligator offspring

A scientist conducted an experiment to determine how the amount of salt in a body of water affects the number of plants that can live in the water. In this experiment, the dependent variable is a) the amount of salt in the water b) the number of plants in the water c) the temperature of the water d) the water

b) the number of plants in the water

Identify the control group for the rat experiments described in the Paralytic Shellfish Poisoning Scenario. a) Group A b) Group B c) Group C

c) Group C

Which of the following statements best describes the data in the graph below? a) In recent years, the rate of cavities has increased in many countries. b) In some countries, people brush their teeth more frequently than in other countries. c) The more sugar people eat, the more likely they are to get cavities. d) The consumption of sugar has increased in many countries in recent years

c) The more sugar people eat, the more likely they are to get cavities.

In an experiment, the one variable that is changed is called the a) controlled variable b) dependent variable c) independent variable

c) independent variable

The process of obtaining information by using the senses is called a/an a) conclusion b) inquiry c) observation d) scientific method

c) observation

A scientist hypothesizes that the temperature at which an alligator's egg is incubated will determine whether the alligator offspring will be male or female. The independent variable is a) the alligator b) the gender of the alligator offspring c) the temperature

c) the temperature

What was the experimental variable for the rat experiments described in the Paralytic Shellfish Poisoning Scenario? a) Marine dinoflagellates, particularly Gymnodinium catenatum b) Paralytic shellfish poisoning c) Rats fed a diet with saxitoxin d) Rats fed a normal diet without saxitoxin e) Saxitoxin (either 10 mg or 100 mg) f) Survival of the rats (or death of the rats) g) Tissue cell cultures

e) Saxitoxin (either 10 mg or 100 mg)

Which of these statements is not an observation? a) Huge numbers of dinoflagellates caused the waters off the African coast to turn red. b) Thousands of people in the nearby area who ate recently-caught raw mussels showed symptoms of headache, nausea, vomiting and tingling sensations. c) 100 of these people died of paralytic shellfish poisoning. d) Gymnodinium catenatum produces saxitoxin. e) In tissue cell cultures, saxitoxin inhibits the movement of sodium into cells. f) Sarah suspected that the patients who died of PSP had ingested higher levels of saxitoxin than patients who lived.

f) Sarah suspected that the patients who died of PSP had ingested higher levels of saxitoxin than patients who lived.

What was the dependent variable for the rat experiments described in the Paralytic Shellfish Poisoning Scenario? a) Marine dinoflagellates, particularly Gymnodinium catenatum b) Paralytic shellfish poisoning c) Rats fed a diet with saxitoxin d) Rats fed a normal diet without saxitoxin e) Saxitoxin (either 10 mg or 100 mg) f) Survival of the rats (or death of the rats) g) Tissue cell cultures

f) Survival of the rats (or death of the rats)