Download Extreme Science Worksheet

JAN – EXTREME SCIENCE
Section 1
Read each question carefully. Choose the m ost suitable answ er.
1. The pyramid of numbers shows that in an ecosystem
A. the number of producers are more than the top consumers.
B. the number of top consumers are more than the producers.
C. there are equal number of producers and consumers.
D. the top consumers are more than the primary consumers.
2. Which of the following is the difference between a food chain and a food web?
A. Food chains are linear, whereas food webs are complex.
B. Food chains involve animals and plants, whereas food webs involve only
animals.
C. Food chains involve only animals, whereas food webs involve plants.
D. Food chains include decomposers, whereas food webs include detritivores.
3. Which of the following organisms are producers?
A. rabbit and deer.
B. grass and phytoplankton.
C. mushroom and leeches.
D. earthworms and millipedes.
4. The primary consumers in an ecosystem are
A. carnivores.
B. herbivores.
C. omnivores.
D. detritivores.
5. The transfer of energy that begins with the Sun and passes from one organism
to the next in the food chain is called
A. energy flow.
B. a food web pyramid.
C. photosynthesis.
D. the food cycle.
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Section 2
Answer the questions in the spaces provided.
6. Study the diagram below and answer the following questions.
a. What is the process in the diagram above called?
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b. How do producers make food? Differentiate between photoautotrophs and
chemoautotrophs.
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c. Name one example of a detritivore.
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d. How do detritivores contribute to the food chain?
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Answer Key
Section 1
1. A. the num ber of producers are m ore than the top consum ers.
Tip: An ecological pyramid (also trophic pyramid, energy pyramid, or sometimes
food pyramid) is a graphical representation designed to show the biomass or
biomass productivity at each trophic level in a given ecosystem. Biomass is the
amount of living or organic matter present in an organism.
2. A. Food chains are linear, whereas food webs are com plex.
Tip: A food web consists of many food chains. A food chain only follows just one
path as animals find food. For example, a hawk eats a snake, which has eaten a frog,
which has eaten a grasshopper, which has eaten grass. A food web shows the many
different paths plants and animals are connected.
3. B. grass and phytoplankton.
Tip: Mushrooms, like moss, reproduce with spore rather than seed and have no
vascular system. They are, however, organisms classified as fungi and not plants.
Mushrooms have no true stems or roots. They have no leaves and no chlorophyll to
produce nutrients for growth.
4. B. herbivores.
Tip: Herbivores are animals that are adapted to eat plants. Herbivory is a form of
predation in which an organism consumes principally autotrophs such as plants,
algae and photosynthesizing bacteria. More generally, organisms that feed on
autotrophs in general are known as primary consumers.
5. A. energy flow.
Tip: Energy flows through an ecosystem in a linear, one-way direction. In all
ecosystems, energy enters the system as sunlight (radiant energy). Producers
(photosynthetic organisms) trap and use about 0.02% of the sun's energy in
photosynthesis.
Section 2
6. a. The food chain.
b. Producers are plants, algae, and some bacteria. They don't get their food from
eating other organisms. However, they do make their own food through either
photosynthesis or chemosynthesis. Collectively, they are called autotrophs
(photoautotrophs if they use light energy to make their food, and
chemoautotrophs if they use energy from inorganic chemical reactions to make
their food).
c. Earthworms, millipedes, woodlice, dung beetles and dung flies.
d. A detritivore feeds on plant and animal remains and other dead matter
collectively called detritus. They recycle decomposing material and return it to
the food chain.
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