Exercises in Science
..............Jack Kimball.............

Cause and Effect


cause : a reason for an effect or result

effect / result : a development, a consequence

organisms : living things

phenomena : facts, occurrences

tide : in- and out-ward movement of the ocean

gravitational pull : natural force of attraction between large bodies, such as the moon and Earth

coral reef : an ocean ridge made of rock-like deposits from organisms called coral

to distinguish : to see a difference

balanced diet : a healthy amount of good food

heartbeat : the pulse of the heart

muscle : body tissue that aids movement

to sweat : to produce body moisture, to perspire


Many phenomena are better understood by describing their causes and effects. When scientists see a connection between one fact and another, they try to show a cause-and-effect relationship. The cause explains why something happens. The effect describes what happens. Almost all writing about science and nature is concerned with cause and effect. For example, why does the ocean's tide move into and out of the shore? In what way does the moon effect this? The answer is that there is a cause-and-effect relationship between the moon and the movement of the ocean. There are several ways to express this.

(1) Because of the moon's gravitational pull, there are ocean tides.

(2) The ocean tides are affected by the moon's gravitational pull.

(3) The moon has a gravitational pull; consequently,there are ocean tides.

Sentence Patterns that Indicate Cause and Effect


Because of / Due to} X, there is Y.

Because of / Due to
}X, Y happens.


X{affects / influences} Y.


Y{ is affected / is influenced}by X.


X{causes / produces / results in }Y.


Y{is caused / is produced by / is a result of / is due to}X.


When / If / Because}there is X, Y happens.


X is {the cause of / the reason for}Y.

Transitions that Indicate Effect

thus, as a consequence, 
therefore, consequently,

Exercise 1
Read the following paragraphs A & B. Underline the topic sentence and also underline words that specify cause and effect.

The ocean's delicate coral reefs are affected by changes caused by humans. To illustrate, dumping waste products and garbage in the sea results in changes in the natural environment. Due to these changes the ocean becomes polluted, and as a consequence, coral reefs are damaged. When the ocean becomes extensively polluted, coral reefs die.

Good health is affected by a balanced diet. On the other hand, if we do not eat well, this could cause problems and we could become very sick. For instance, if our diet lacks Vitamin A, blindness may result. Many problems affecting the skin and the teeth are due to a lack of Vitamin C. When our diet contains recommended amounts of Vitamin A and C, however, our ability to fight diseases like cancer is greatly affected. So it makes sense to eat well because this results in a longer and healthier life.

Exercise 2
It is useful to distinguish between the cause and the effect. In each of the following (1-5), one sentence is the cause and the other is the effect. Write a "C" next to the cause, and write an "E" next to the effect. Then rewrite the sentences into one sentence. Be sure to use vocabulary that specifies cause and effect.

(1)___ (a) There is no life on Venus. ___ (b) There is no atmosphere on Venus.

(2)___ (a) Solar batteries need to be recharged frequently. ___ (b) Solar batteries are impractical for powering cars on long trips.

(3) ___ (a) The element silicon melts. ___ (b) The temperature is above 1410°C.

(4) ___ (a) Daily exercise strengthens the heart. ___ (b) Many people who exercise daily have healthy hearts.

(5) ___ (a) Cakes and candy are high in sugar. ___ (b) Cakes and candy are bad for the teeth.

Exercise 3
In (a), (b) and (c), below, there is one sentence that contains a cause. Write one or two sentences that describe effects that result from each cause. Here is an example.

CAUSE: Nitrogen oxide from car exhaust causes problems. EFFECTS: One effect is that air pollution is produced by car exhaust. Car exhaust results in acid rain, as well.

(a) CAUSE: Not eating a balanced diet results in bad effects. EFFECTS:_____

(b) CAUSE: Because of today's computers we can do many things. EFFECTS:_____

(c) CAUSE: Trees, flowers and other plant life have positive effects.

Exercise 4
In (a) and (b), below, there is one sentence that contains an effect. Write one or two sentences that explain causes. For example:

EFFECT: My best grades are in science courses.

CAUSES: I study harder for my science courses because I like subjects in science. When I study harder, I get good grades.

(a) EFFECT: More and more forest plant life is being destroyed. CAUSES:_____

(b) EFFECT: I feel healthy. CAUSES:_____


Writing Exercise

Causes produce various effects. If these effects continue over time, they often cause additional effects. Hot weather affects humans by causing rapid heartbeat and muscle pain. Rapid heartbeat and muscle pain can result in people feeling tired and becoming ill. Listed below are causes and various effects related to problems with hot weather. Write two paragraphs in which you explain the causes and effects of such phenomena.

In the first paragraph describe the effects listed below (and any other effects you can think of). In the second paragraph describe the effects of pain, high body temperature, loss of body water, etc. Please use sentence patterns and vocabulary that specify cause and effect.

Paragraph 1

CAUSE: hot weather

EFFECTS: the body temperature rises; muscle pain develops; the heartbeat becomes rapid

Paragraph 2

CAUSE: high body temperature

EFFECTS: the body sweats; the body loses water

CAUSE: muscle pain

EFFECTS: many people feel tired, weak

CAUSE: loss of body water; feeling tired, weak

EFFECTS: serious illness