Unit 1 Replay ERQs

What would be the control group if a student was testing the benefits of a new fertilizer on the growth of tomato plants?

• Tomato plants grown with no fertilizer

• Tomato plants grown with only the original type of fertilizer

• tomato plants grown in different types of soil with the new fertilizer

• Different varieties of tomato plants grown with the new fertilizer

In a biology lab, students conducted a seed-germinating experiment. They wrapped seeds in paper towels soaked in different solutions. The paper towels were placed in separate petri dishes and kept at a constant temperature. The setup of the experiment is represented in the table below.

After 7 days, the students counted the number of seeds that had germinated. Which change in procedure would improve the experiment?

• Using one type of seed for all three solutions

• Decreasing the number of seeds in each paper towel

• Storing the seeds in each petri dish at different temperatures

• Increasing the number of days seeds are exposed to the solutions

Thomas and Julie wanted to find out which material would insulate their teacher's coffee cup to keep the coffee hot for the longest period of time. They first wrapped her cup with bubble wrap and recorded the temperature of the coffee once every 15 minutes for 2 hours. They repeated the investigation, this time using newspaper instead of bubble wrap, but they got the same results for both materials. What could they do to make their results more valid?

• Repeat the experiment three times

• Use a different type of thermometer

• Repeat the experiment 100 more times

• Conduct the experiment in much colder conditions

Nicholas is studying the effects of adding mulched leaves to soil used to grow tomatoes. He normally adds 5 kg of mulched leaves to soil to grow tomatoes. He placed an identical quantity and type of soil into four 10” pots. He added 20 kg of mulched leaves to the first pot, 15 kg to the second, 10 kg to the third, and 5 kg to the fourth. The same species and size of tomato plant were then placed in each pot. All the pots were placed in sunlight and watered with equal amounts of water at 8:00 am each day. After 60 days, tomatoes obtained from each pot were weighed and recorded.

Match the following:

• Amount of Mulched Leaves

• Dependent Variable

• Pot getting 5 kg of leaves (normal amt)

• Independent Variable

• Amount of Water, Sun, species/size plant

• Control Group

• Weight of Tomatoes

• Constants

Adhesion occurs when water is attracted to other polar substances. Which of the following is an example of adhesion in organisms?

• Capillary action of liquid in plant stems

• Release of sweat to reduce body heat

• Movement of ions to maintain homeostasis

• Pumping of blood through the circulatory system

Water has a much higher specific heat than most other covalent compounds. What do you predict might happen if water had a low specific heat instead?

• Flooding would occur and animals would be forced to migrate.

• Harmful organisms living in water would reproduce at a rapid rate.

• Organisms that are sensitive to changes in temperature would die.

• Plants would not have enough water to effectively carry out photosynthesis.

Many fish and aquatic plants can survive a cold winter because the layer of ice that forms at the top of the lake insulates the water below and prevents the lake from freezing solid. What unique property of water contributes to this effect?

• 1. Water absorbs heat when it evaporates and forms a gas.

• Water expands and becomes less dense when it freezes.

• 1. Water molecules separate into ions in solutions.

• 1. Water forms hydrogen bonds with ions and other polar substances. 

What is the independent and dependent variable, respectively?

• Temperature ; Density

• Density ; Temperature

• How density affects temperature

• How temperature affects water

As the temperature of water increases, what happens to the density?

• The density of water increases

• The density of water decreases

• There is no change in density

• The temperature declines at a steady rate

Human blood contains approximately 83% water. Which property of water makes it an essential component for carrying nutrients and gases in the body?

• Water has a pH of 7

• Water expands when frozen

• Water has high specific heat

• Water dissolves many substances