Unit Review Key (2012)

What Bone Cells Need
1. Think about the bone investigation. Explain why bone cells need the nutrient
calcium to function properly.
Bone cells need the nutrient calcium so they stay strong and rigid. They will not support
the body if they are soft.
2. What do bone cells (and all human body cells) need to function properly
besides just nutrients?
All bone cells need nutrients, oxygen, and water.
Muscle Investigation
1. Colin investigated how many sit ups he could do in 30 seconds. He did five
trials. Between each trial, he rested for 30 seconds. His results are below:
Trial 1:
Trial 2 :
Trial 3:
Trial 4:
Trial 5:
20 sit-ups
17 sit-ups
16 sit-ups
14 sit-ups
9 sit-ups
Do you notice a pattern in how many sit-ups Colin can do in each trial? Explain
your answer.
The pattern is that the number of sit-ups is decreasing.
2. Think about the pattern, and then explain what you think happened to Colin’s
muscle cells as he continued to exercise.
The muscle cells needed more nutrients, oxygen, and water than they were getting, so
he experienced muscle fatigue. The muscle cells didn’t have enough energy to continue
Comparing Cells
Review science notebook pages 42-45 from Lesson 11 to help you answer the
following two questions.
1. You sketched and described some cells that were part of an alien from the
mythical planet of Zorr. If those cells were part of a human body instead of an
alien, what 3 things would those cells (like all human body cells) need to
function properly?
All human body cells need oxygen, nutrients, and water.
2. Your alien has more than one type of cell in its body. Is this similar to the
human body? Why or why not? Give examples of different body cells to
explain your answer.
The aliens are similar because the human body is made up of many different kinds of
cells, such as brain cells, muscle cells, skin cells, and lung cells just like the aliens.
Supporting Active Muscle Cells
Blood carries what 3 things to muscle cells so they can make energy?
The blood carries nutrients, water, and oxygen to the muscles so they can make energy.
A woman recorded her heart rate while she did three different things, and
wrote down the following information:
Activity A:
Activity B:
Activity C:
75 heartbeats per minute
140 heartbeats per minute
103 heartbeats per minute
Based on her results, which activity letter do you think she was sprinting?
Activity B
Based on her results, which activity letter do you think she was sitting
Activity A
True or False? If false, rewrite the statement to make it true.
When you exercise, your heart beats faster.
You checked your pulse for 15 seconds and counted 20 throbs. How fast is
your heart beating per minute (heart rate)?
80 beats per minute
Which gas enters your body when you inhale?
Oxygen enters your body as you inhale.
Which gas exits your body when you exhale?
Carbon dioxide exits your body when you exhale.
What are the main organs of the respiratory system?
The lungs are the main organs of the respiratory system.
1. True or False? If false, rewrite the statement to make it true.
The more active muscles cells are, the less energy they need.
The more active muscles cells are, the more nutrients (energy) they need.
Humans are multi-cellular organisms.
2. Write 2-3 sentences that explain the relationship between these 4 words:
Cells, tissues, organs, systems.
Cells are the building blocks of the human body and combine to form tissues. Tissues
are groups of cells working in a unit, and combine to form organs. Organs are made up
of several tissues and combine to form systems, which are two or more organs working
together to accomplish an essential task.
Cells tissue organssystems
Working Together
Read the paragraph below and then describe in the second column of the table how
each body system helped Amanda move her arm. Be sure to write an answer for all
six systems.
Amanda is playing a softball game with her team. Everyone wants to win the game,
and everyone’s body is working hard. Amanda throws a softball as fast as she can to
her teammate on third base. She’s a good thrower and she gets the ball there
before the other team’s runner can touch the base. Amanda is happy all her systems
helped her move her arm so she could throw the ball so fast.
This system:
Helped Amanda move her arm by doing this:
Bones support the body and protect organs, and
are attached to muscles. Bones move at joints.
Muscles pull on the bones to move them, and gives
her power to throw.
Her eyes see the play, and send the message through her to
nerves to her brain. Her brain makes a decision, then sends a
message to her arm muscles to throw the ball.
Her heart pumps blood which brings NOW (nutrients,
oxygen, and water) to the muscle cells so they can have
This system carries oxygen to her blood, which carries it to
her muscle cells.
This system also carries away carbon dioxide.
The digestive system breaks down food, and puts the
nutrients and water into the blood, to be taken to the cells
for energy.