BIOLOGY REVIEW (MANSOUR)
Q 20, 21, 22: Watching the behavior of earthworms in soil, a biology student suggested that the penetration of air into the soil promotes the root development of plants. The student then set up the following experiment. 20. The important data to be recorded in this experiment will come from the observation of the increase in 1) Leafs size 2) stem size 3) number of leaves 4) number of roots 21. State the hypothesis being tested. 22. State one way to improve this experiment to make it more reliable.
20. 4 21. If there is more air in the soil, then it will affect the growth of roots OR The amount of air available will affect growth of roots 22. increase sample size
Q 3: A student prepared the following list of steps for performing a laboratory investigation. She admitted one important step for completing the investigation Steps for an experiment: 1. Define a problem 2. Develop a hypothesis 3. select suitable laboratory materials and perform a controlled experiment to test the hypothesis 4. Collect, organized, and graph the experimental data 5. ? State the procedure that is missing in the chart
5. reach a conclusion
Q 9, 10, 11: A student placed five geranium plants of equal sides in five environmental chambers. Growing conditions were the same for each plant except for that each chamber was illuminated by a different color of light of the same intensity. At the end of 20 days, the plant growth was measured. 9. State a possible hypothesis for the experiment 10. what control should be used in this experiment 11. describe one modification you would make in the design of this experiment to make the results more reliable
9. If a plant is place under a different color light, it will affect plant growth OR plats grown in different color of light will grow different amounts 10. white light 11. increase sample size (more plants under the same color)
Q 17: Scientists breed mice to be as genetically alike as possible to use in experiments. Explain why scientists would want mice that are genetically alike
Correct Answer: - Differences in mice are not likely to affect the experiment results - Because genetically identical subjects will be more controlled and it will be more consistent
Pg 148 Q 1: After doing an experiment for the first time, what should a student do before making a conclusion? 1) nothing because this inference is a valid scientific fact 2) repeat this experiment several times and obtain similar results 3) Repeat this experiment several times using different variables 4) develop a new hypothesis and test it
Correct Answer: 2 2 is correct because repeating the experiment with the same variables will make sure your test results are reliable
Q 12: A new drug for the treatment of asthma is tested on 100 people. The people are evenly divided into two groups. One group is given the drug, and the other group is giving a glucose pill. The group that is given the glucose pill serves as the 1) experimental group 2) limiting factor 3) control 4) indicator
Correct Answer: 3
Q 13: The part of a laboratory experiment, a thin slice of peeled raw potato weighing 10 grams is placed in an oven at 80° C. After 5 hours, the potato sample is removed from the oven and wait again. The purpose of this experiment might be to 1) test for the presence of starch in living tissue 2) isolate cells in various stages of cell division 3) determine the water content of potato tissue 4) study the rate of photosynthesis in a potato
Correct Answer: 3
Q 18: Conducted an original, well-designed experiment, carefully following the proper scientific procedure. In order for the conclusions to become generally accepted, the experiment must 1) Contain several experimental variables 2) Support the original hypothesis 3) Be repeated to verify the reliability of the data 4) Be conducted by scientists
Correct Answer: 3
Q 19: A student tosses a coin five times and observed results of four tails and one head. He concluded that when a coin is tossed, there is an 80% chance of getting a tail and a 20% chance of getting your head. The conclusion would be more valid if 1) Only two tosses of the coin had been used 2) the weight of the queen had been taken into consideration 3) a greater number of tosses had been used 4)The surface of the coin landed on had to been taken into consideration
Correct Answer: 3
Pg 153 Q 6: A Drug Company tested a new medication before putting it on the commercial market. Pills without medication were given to 500 test subjects in group a, and pills with medication were given to 500 subjects in group b. In this experiment, the individuals in group a served as the... 1) Host group 2) Dependent variable 3) Control 4) hypothesis
Correct Answer: 3 The host group could also be called the experimental group
Q 7: In order to find the percentage of organic matter in soil from several different locations, a student collected the samples, weighed them immediately, roasted them for several minutes in a flame to burn off organic matter, and weighed them again. The student concluded that the difference between the first and second weight represented the weight of the organic matter in the soil. The most serious mistake that the student made in this experiment was in ... 1) taking large samples 2) weighing the samples before weighing them 3) failing to dry the samples before first weighing them 4) assuming that roasting them could remove organic matter
Correct Answer: 3 Water has weight so after roasting them the weight of the water is gone and potentially some organic matter is gone too
Q 4: When heavy rains occur while apple orchards are in bloom, the apple crop the following fall is much smaller than normal this information can be best described as ... 1) an inference 2) a hypothesis 3) a prediction 4) an observation
Correct Answer: 4
Q 5: The steps listed below would be the first in a scientific investigation? 1) perform the experiment 2) analyze the experimental data 3) formulate a hypothesis 4) Define the problem to be investigated
Correct Answer: 4
Q 16: In an attempt to demonstrate the effectiveness of a new vaccine a scientist performed these experimental procedures: - 100 genetically similar rats were divided into two groups of 50 rats each - each rat in group a was given an injection of the vaccine in a glucose and water solution - each rat in group b was given an injection of the glucose and water solution containing no vaccine - After several weeks, all wrapped in both groups were exposed to the disease for which the vaccine was developed Identify the dependent variable that was studied in this experiment
Correct Answer: If they developed a disease
Q 15: jim Wants to shorten the ripening time for tomatoes. He predicts that the more water the seedlings receive, the faster the tomatoes will ripen. To test his prediction he grows 20 tomato plants in a garden in full sunlight that has dry soil and 20 in a garden in a shady your location where there is greater moisture content in the soil. He then record the time it takes for the fruit to develop and write on the plants in each Garden location. State a serious error the student made with the design of the experiment.
Correct Answer: There are two dependent variables: light and moisture
Q 8: In an investigation to determine the effect of environmental pH on the germination of dandelion seeds, 25 dandelion seeds were added to each of five Petri dishes. Each dish contained a solution that differed from the others only and it's Phi shown below. All other environmental conditions were the same. The dishes were covered and observed for 10 days. State the independent variable in this investigation.
Correct Answer: pH
Q 14: Describe the function of a control group in an experiment
Correct Answer: used for comparison
