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7th Grade Regents – Midterm Review Sheet Answer Key
Life Science:
1. Why do we use stain to observe specimens under the microscope?
 To better visualize the cell and cell organelles under the microscope.
2. When observing a specimen under the microscope, you move the slide to the left.
In what direction does it appear to move under the microscope?
 Right
3. What part of the microscope should you never use under high power?
 Course adjustment knob
4. Why do we place the coverslip on a 45 degree angle?
 To prevent air bubbles
5. If the field of view has a diameter of 4mm, what is the size of the cell below?
 1.0 mm
6. Base your answers to questions on the graph below.
 What was the starting temperature of the water? 50 oC
 What was the temperature of the water after it was heated 2 ½ minutes?
70 oC
 Predict the temperature of the water after it was heated for 6 minutes.
110 oC
7. An observation is gathering information by using our five senses
8. An inference is using your observations to make a prediction
9. A student wants to see if a name brand fertilizer works better than a store brand
fertilizer. She feels the name brand is more expensive because it is more potent
(stronger/works better).
 What should her hypothesis be?

The student will predict that the “name brand” fertilizer will
work better than the “store brand” fertilizer because it is more
potent.
 What is the dependent (responding) variable?

The growth (height) of the plant.
 What are two variables that should be held constant?

Amount of water given.

Amount of sunlight received.

The type of plants the student is using.
 What would be a control?

A control would be to grow the plant using no fertilizer to use
as a comparison.
 What are two ways to make an experiment more valid?

Repeat it

Use a large sample size
10.Describe the difference between kingdom and species.
 Kingdom includes all the species of a given Kingdom.
 Ex. All animals in the Animalia Kingdom
 Lions, Tigers, Humans, Bees, Grasshoppers, Butterfly.
 Species are most specific and is narrowed down into just one type of
organism in that Kingdom.
 Ex. Humans
11.Which Kingdom do Yeast belong to?
 Fungi Kingdom
12.Which Kingdom does an Owl belong to?
 Animalia Kingdom
13.What do all living things have in common?
 All living things are made of cells.
 Living things must perform ALL life processes.
 All living things need energy to survive.
14.Describe the function of the following cell structures:
 Cell Wall – The outermost part of the plant cell that protects, supports,
and provides structure. Made of cellulose.
 Cell membrane – Is selectively permeable allows certain materials in
and out of the cell.
 Vacuole – Stores food, water, and waste.
 Cytoplasm – Jelly-like substance in a cell where all life activities take
place.
 Nucleus – controls all life activities of the cell.
 Chloroplast – Site of photosynthesis.
15.What are the three parts of the cell theory?
 All living things are made up of cells
 The cells are the basic unit of structure and function in living things
 All cells come from preexisting cells.
16.What are two differences between plant and animal cells?
 Plant cells have a Cell Wall and Chloroplast.
17.Describe the following processes: photosynthesis and respiration. Write the
formulas for each process and describe what occurs in each process.
 Photosynthesis is the process where plants produce oxygen and glucose
(food).
o CO2 + H20  C6H12O6 + O2
o Carbon dioxide + Water  Glucose + Oxygen
 Respiration uses oxygen to break down the bonds in food to release energy.
o C6H12O6 + O2  CO2 + H20 + ATP
o Glucose + Oxygen  Carbon dioxide + Water + energy
18.What processes do all cells undergo?
 All cells undergo reproduction.
19.What is cell division? What is it used for in unicellular organisms and in multicellular
organisms?
 When a cell divides into two identical daughter cells. Also known as Mitosis.
o All offspring are identical.
 Unicellular – use cell division to reproduce
 Multicellular – use cell division for growth and repair
20. The best way to tell if organisms are closely related is through genetic evidence
(DNA)
 Gel electrophoresis is a method that can examine the evolutionary
relationships between different organisms.
21. What is cancer?
 Cancer is uncontrolled cell division.
22.Describe the difference between asexual and sexual reproduction. Give examples of
each.
 Asexual Reproduction – involves one parent cell
o Amoeba , Bacteria reproducing
 Sexual Reproduction – involves two parent cells
o Humans – combining the sperm (male) and egg (female) sex cells.
o The ability to regrow lost body part is called regeneration.
23.What are a stimulus and a response? Give an example of each.
 Stimulus – Change that causes a response
o Lights go out.
 Response – Reaction to a change or stimulus
o Pupils dilate
24.How do plants and animals interact?
 Plants provide animals’ food and oxygen through the process of photosynthesis.
 Animals provide plants’ with CO2 through the process of cell reparation.
25.What are microorganisms? Explain two ways they are helpful and two ways they are
harmful.
 Microorganisms are organisms that are too small to be seen with the naked eye
(need a microscope).
 They are helpful because they flavor foods and help in environmental cleanup.
 They are harmful because they cause disease and spoil food.
26. Organisms that break down dead organisms and return nutrients to the
environment are decomposers
27.Describe the function of the following plant parts: leaves, roots and stems.
 Leaves – Site of photosynthesis.
 Roots – Absorbs water from the soil and anchors the plant to the ground.
 Stems – Support the leaves.
o Xylem (carries water) and Phloem (carries food) found in the stem helps
transport materials from the roots to the leaves.
***Plants reproduce sexually when pollen from the Stamen (anther) reaches the Pistil
(stigma) and produces seeds.
28.What is a life cycle?
 Developmental changes that an organism goes through in its life.
29.What is metamorphosis? Name two types of organisms that undergo
metamorphosis.
 Metamorphosis – developmental changes that an organism goes through.
 Grasshopper
o Incomplete metamorphosis – only has three stages (egg, nymph, and
adult)
 Butterfly
o Complete metamorphosis – has four stages (egg, larvae, pupa, adult)
30.Label the following diagram of the skeleton:
Cranium
Humerus
Vertebrae
Pelvis
Femur
31.Which bone protects the spinal cord? Brain?
 The vertebrae protect the spinal cord.
 The cranium protects the brain.
32.What is the largest bone in the body?
 The largest bone in the body is the femur.
33.List the levels of organization form least complex to most complex.
 Cells  Tissues  Organs  Organ Systems  Organism
34. Ecological succession is the gradual process by which ecosystems change and
develop over time.
35.Vaccines are biological preparations made up of dead or weakened pathogens
 A vaccine works by stimulating the production of antibodies.