All Free Biology MCQs with Answers

1711. An educated guess is called:

• A. Accumulated Data
• B. Observation
• C. Hypothesis
• D. Conclusion

Explanation: A hypothesis is a tentative, testable explanation proposed from observations and available evidence, so it is often described at an introductory level as an educated guess. Students may choose conclusion because it follows investigation, but a conclusion is reached after testing the hypothesis, not before it.

1712. Steps Involved in scientific method are ?

• A. Hypothesis ->Accumulated data -> observation & experimentation -> conclusion
• B. New data -> Conclusion -> Accumulated data -> Observation & experimentation
• C. Accumulated data - New data - Observation & experimentation - Hypothesis -> Conclusion
• D. Accumulated data -> Hypothesis -> Observation & experimentation -> New data -> Conclusion

Explanation: A scientific investigation generally begins with accumulated observations or data, followed by a hypothesis. The hypothesis is tested through observation and experimentation, which produce new data before a conclusion is drawn. Option a is tempting because it includes the same steps, but it places the hypothesis after experimentation.

1713. Members of one species inhabiting the same are form__________?

• A. Species
• B. Community
• C. Ecosystem
• D. Population

Explanation: A population consists of members of the same species living in the same geographical area at the same time. A community contains populations of different species, whereas an ecosystem also includes non-living environmental factors. The likely alternative is community, caused by overlooking the phrase “one species.”

1714. A group of very similar inter breeding organisms constitutes?

• A. Biosphere
• B. Ecosystem
• C. Population
• D. Species

Explanation: A species is a group of similar organisms that can interbreed and produce fertile offspring. A population is only the members of that species living in one particular area, so the wording here defines species more broadly. Students may choose population because it also describes groups of organisms, but it does not necessarily include all members of a species.

1715. Two or more populations of different species living and interacting in the same area form

• A. Biosphere
• B. Community
• C. Population System
• D. Ecosystem
• E. Species

Explanation: A community consists of populations of different species living and interacting in the same area. An ecosystem includes that community plus abiotic factors such as light, water, soil, and temperature. Students may choose ecosystem because interaction is mentioned, but no non-living components are included in the definition.

1716. Kingdom Protoctista includes____________?

• A. Fungi
• B. Prokaryotes
• C. protists
• D. Piantae

Explanation: Protoctista, commonly called Protista, is a kingdom containing mostly unicellular eukaryotic organisms such as Amoeba, Paramecium and many algae. Fungi are placed in their own kingdom, while prokaryotes belong to kingdoms such as Monera. Students may choose fungi because some protists resemble fungi in lifestyle, but resemblance does not place them in the same kingdom.

1717. The word "BIOLOGY" has been derived from_________ word?

• A. Latin
• B. English
• C. Greek
• D. French

Explanation: The term biology comes from Greek roots: bios means life and logos means study or knowledge. Latin and French are also important scientific languages, but they are not the source of this word. Students may choose Latin because many biological names are written using Latinized forms.

1718. The scientific study of livings is called?

• A. Anatomy
• B. Biology
• C. Geology
• D. Zoology

Explanation: Biology is the scientific study of living organisms, including their structure, functions, reproduction and relationships. Anatomy studies body structure, while zoology specifically studies animals, so each is narrower than biology. Students may choose zoology because it is also a branch of the biological sciences.

1719. Spongocoel is present in ____________?

• A. Cnidaria
• B. Porifera
• C. Mollusca
• D. Nematodes

Explanation: The spongocoel is the central cavity of a sponge and is found in members of phylum Porifera. Water enters through pores, passes into the spongocoel and exits through the osculum. Students may choose Cnidaria because cnidarians also have a body cavity, but their cavity is called the gastrovascular cavity, not the spongocoel.

1720. Largest invertebrates is _____________ ?

• A. Earthworm
• B. Euglena
• C. Squids
• D. Star fish

Explanation: The giant squid is regarded as the largest invertebrate, with some species reaching very great lengths and masses. Students may choose starfish because it is a familiar invertebrate, but starfish are much smaller than giant squids.