Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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- A. Zooflagellates
- B. Foraminferans
- C. Aetinopods
- D. Apicomplexans
Explanation: Foraminiferans have calcium carbonate shells, and the accumulated shells and remains of these organisms contribute substantially to…
Correct answer: Foraminferans- A. Most of them are unicellular
- B. They have blooms
- C. Their cells are often covered with shells of interlocking cellulose plates impregnated with calcium
- D. None of these
Explanation: Most dinoflagellates are unicellular and many produce blooms, while many have cellulose plates forming a theca.
Correct answer: Their cells are often covered with shells of interlocking cellulose plates impregnated with calcium- A. Chondrus
- B. Polysiphonia
- C. Both of these
- D. Pinnularia
Explanation: Chondrus and Polysiphonia are both red algae, or rhodophytes, containing red pigments such as phycoerythrin.
Correct answer: Both of these- A. Contain mainly unicellular organisms.
- B. Their contractile vacoule is respobsible for water regulation.
- C. They are even capable of sexual reproduction.
- D. Diploid nucleus being smaller is responsible for cells metabolism and growth while polyploidy nucleus functions in sexual process.Biological Sciences
Explanation: In ciliates, the diploid micronucleus is involved mainly in sexual reproduction, whereas the usually polyploid macronucleus controls…
Correct answer: Diploid nucleus being smaller is responsible for cells metabolism and growth while polyploidy nucleus functions in sexual process.Biological Sciences- A. Zooflagellates
- B. Actinopods
- C. Foraminifera
- D. Apicomplexans
Explanation: Radiolarians are actinopods, characterized by fine, radiating axopodia supported by a central skeletal structure.
Correct answer: Actinopods- 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.
Correct answer: Choanflagellates- 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.
Correct answer: All of these- 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…
Correct answer: Herbert Copeland- 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…
Correct answer: Haploid- 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…
Correct answer: They only include unicellular aquatic eukaryotic organisms- 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.
Correct answer: Phytophthora infestans- 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…
Correct answer: 2-9- 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.
Correct answer: Asexual- 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…
Correct answer: 95%- 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.
Correct answer: Crustose- A. Sporing
- B. Conidiation
- C. Budding
- D. Fragmentation
Explanation: Fragmentation is the asexual reproduction method in which a mycelium breaks into pieces and each viable piece grows into a new mycelium.
Correct answer: Fragmentation- A. Arthrobotrys
- B. Pleurotus ostreatus
- C. Mildews
- D. All of these
Explanation: Arthrobotrys is a predatory fungus that forms constricting adhesive rings around nematodes; the rings tighten when a nematode enters and…
Correct answer: Arthrobotrys- A. Sporing
- B. Conidiation
- C. Budding
- D. Fragmentation
Explanation: Yeast is a unicellular fungus that commonly reproduces asexually by forming a small outgrowth called a bud, which enlarges and separates…
Correct answer: Budding- A. Mildew
- B. Constricting ring
- C. Haustoria
- D. All of these
Explanation: Haustoria are specialized hyphal projections that enter or grow against host cells and absorb nutrients from living plant tissue.
Correct answer: Haustoria- A. Mushroom
- B. Yeast
- C. Penicillium
- D. Mold
Explanation: Yeast is a unicellular fungus whose body consists of individual cells rather than a network of elongated hyphae.
Correct answer: Yeast