All Free Biology MCQs with Answers

1631. Which of the protozoa has a striking resemblance to collar cells in sponges_____________?

• A. Zooflagellates
• B. Choanflagellates
• C. Trypanosomoa
• D. Trichonymphas

Explanation: Choanoflagellates possess a collar of microvilli surrounding a flagellum, closely resembling the choanocytes, or collar cells, of sponges. Trypanosoma and Trichonympha have flagella but lack this distinctive collar arrangement, so students may select a by treating all flagellated protozoa as similar.

1632. In slime molds spores develop into__________?

• A. Swarm cells
• B. Biflagellated cells
• C. Amoeboid reproductive cells
• D. All of these

Explanation: Slime-mold spores can germinate into amoeboid cells or flagellated swarm cells, and in some forms these swarm cells are biflagellated. Since all three descriptions refer to possible products or forms arising after germination, option d is the best answer; students may choose c if they remember only the amoeboid form.

1633. Who first separated bacteria from other protists as a group_____________?

• A. John Hogg
• B. Ernst Haeckel
• C. Margulis and Schwartz
• D. Herbert Copeland

Explanation: Herbert Copeland proposed a separate kingdom, Monera, for prokaryotic organisms such as bacteria, separating them from the eukaryotic protists. Haeckel introduced Protista but did not make this specific separation, so students may choose b because he is strongly associated with early kingdom classification.

1634. Spores produced by slime molds are__________?

• A. Haploid
• B. Diploid
• C. Triploid
• D. None of these

Explanation: Slime-mold spores are formed after meiosis and are therefore haploid, allowing them to germinate into haploid amoeboid or flagellated cells. Students may choose b by confusing the diploid plasmodial stage with the haploid spore stage.

1635. Which of the following statement about Kingdom Protista is incorrect_______________?

• A. Their members have characteristics which separate them from other kingdoms
• B. They only include unicellular aquatic eukaryotic organisms
• C. They do not develop from Blastula or embryo
• D. They contain ancestors for fungi plants & animals

Explanation: Protista is a diverse kingdom containing unicellular, colonial and some multicellular eukaryotes, so it is incorrect to say that it includes only unicellular aquatic organisms. Students may choose a because protists are defined partly by their diversity, but that diversity is actually why option a is correct.

1636. Which of the following is responsible for Irish potato famine?

• A. Dinoflagellates
• B. Kleps
• C. Physarum polycephalum
• D. Phytophthora infestans

Explanation: Phytophthora infestans is an oomycete that caused the Irish potato famine by producing late blight in potato crops. Physarum is a slime mold and dinoflagellates are aquatic protists, so students may choose c if they associate all fungus-like organisms with plant disease.

1637. Fungi can tolerate pH from____________?

• A. 3-7
• B. 2-6
• C. 2-9
• D. 3-6

Explanation: Fungi generally tolerate acidic conditions and may grow across approximately pH 2 to pH 9, although their optimum is commonly in the acidic range. Students may choose b because pH 2 to pH 6 is a more typical preferred range, but it does not represent the full tolerance range given in standard texts.

1638. Spores in sporangia are produced by process?

• A. Sexual
• B. Asexual
• C. Both of these
• D. None of these

Explanation: Spores formed inside a sporangium are commonly sporangiospores produced by mitosis, so this is an asexual process requiring one parent. Students may choose c because fungi also reproduce sexually by spores, but sexual spores are not the usual meaning of spores produced in a sporangium in this question.

1639. Mycorrhizae are found in about__________vascular plants?

• A. 90%
• B. 95%
• C. 98%
• D. 96%

Explanation: Mycorrhizal associations occur in about 95% of vascular plant species, with fungal hyphae improving mineral and water absorption in exchange for plant carbohydrates. Students may choose c because the association is extremely common, but the standard approximate figure is 95%.

1640. Type of lichen which tightly attaches to rocks is_____________?

• A. Parmelia
• B. Fruticose
• C. Foliose
• D. Crustose

Explanation: Crustose lichens form a thin crust that is tightly attached to rocks and is difficult to remove without damaging the substrate. Foliose lichens are leaf-like and loosely attached, while fruticose lichens are branched, so students may choose c if they confuse a flat shape with tight attachment.