Mid-Term Exam
Constructed Response
Questions and Answers
Question 1
What is the difference between independent
variables, dependent variables, and constant
variables? Be able to identify each in an
example investigation.
Answer for Question 1
An independent variable is the manipulated variable. It is
what you are testing. It is the variable that is changed. A dependent
variable is the responding variable. It responds to what is being tested
(independent variable). It is also the variable that is measured. A
constant variable is a controlled variable. It stays the same throughout
the investigation.
***THERE WILL BE A SIMILAR INVESTIGATION ON THE TEST.
Airplane Investigation
A group of students were conducting an investigation to see if
the weight of an airplane affects the distance that the airplane will
travel. They used a plane that weighed 2 ounces, a plane that weighed
4 ounces, and a plane that weighed 6 ounces. The size of the paper
and the type of paper were both the same. The force used to throw
each plane was also the same.
The independent variable is the weight of the planes.
The dependent variable is the distance traveled by the airplanes.
The constant variables are size of the paper, the type of paper, and
the force used to throw the plane.
Question 2
What are the cell parts and their functions in
plant cells and animal cells?
Answer for Question 2
Type of Cell
Structure
Function
Animal/Plant
cell membrane
Allows materials to enter and exit the cell
Plant only
cell wall
Rigid outer covering with a boxy shape
Animal/Plant
cytoplasm
Clear jelly-like fluid in which the organelles are
suspended
Animal/Plant
Endoplasmic
reticulum
Produce many substances
Animal/Plant
Ribosomes
Produce proteins
Animal/Plant
Golgi Apparatus
Receives materials from the ER, packages them,
and distributes them
Animal/Plant
Nucleus
Directs all activities of the cell
Animal/Plant
Mitochondria
The powerhouse of the cell; produces energy
Plant only
Chloroplast
Captures energy from the sun and uses it to make
food
Animal only
Lysosomes
Break down food particles and old cell parts
Animal/Plant
vacuole
Stores food, water, or other materials
Question 3
Explain the processes of photosynthesis and
cellular respiration. How are these processes a
cycle?
Answer for Question 3
The process of photosynthesis uses energy,
carbon dioxide, and water to make glucose and
oxygen. The process of cellular respiration uses
oxygen and glucose to make energy, water, and
carbon dioxide. It is a cycle because the
products from photosynthesis (glucose and
oxygen) are used as the reactants during cellular
respiration. The products from cellular
respiration (carbon dioxide and water) are used
as the reactants for photosynthesis.
Question 4
How are meiosis and mitosis different?
Answer for Question 4
ANY OF THESE THREE WILL WORK.
Mitosis
Meiosis
1. Makes 2 daughter cells.
2. Makes 2 diploid cells. Diploid
cells are made of 46
chromosomes.
3. Parent cell splits into two exact
copies of itself with the same
amount of chromosomes (46
chromosomes).
4. The daughter cells have the
same genetic material.
5. All human body cells divide this
way except the egg and sperm
cell.
6. One cell division occurs.
7. Used for growth, repair, and
asexual reproduction (one
parent).
1. Makes 4 sex cells (female egg
cells or male sperm cells).
2. Makes four haploid cells.
Haploid cells are made of 23
chromosomes.
3. Parent cell splits into a cell that
has half the DNA or genetic
material (23 chromosomes).
4. The daughter cells or sex cells
have a blend of genes from the
parents.
5. Only the egg and sperm cell are
created by meiosis.
6. Two cell divisions occur.
7. Used for sexual reproduction
(two parents).