Free Biodiversity and Variety of Life MCQs with Answers

1751. Pteridophytes differ from mosses/bryophytes in possessing

• A. Independent gametophyte
• B. Well developed vascular system
• C. Archegonia
• D. Flagellate spermatozoids

Explanation: Pteridophytes differ from mosses/bryophytes in possessing: Well developed vascular system The most significant difference between pteridophytes and mosses is the presence of a well-developed vascular system in pteridophytes. A vascular system is a network of specialized tissues that transport water and nutrients throughout the plant. Mosses do not have a vascular system, which is why they are limited in size and can only grow in moist environments. Independent gametophyte Both pteridophytes and mosses have a life cycle that alternates between two generations: a gametophyte and a sporophyte. The gametophyte is the haploid generation that produces gametes, while the sporophyte is the diploid generation that produces spores. In mosses, the gametophyte is the dominant generation, while in pteridophytes, the sporophyte is the dominant generation. Archegonia: Both pteridophytes and mosses have archegonia, which are female reproductive structures that produce eggs. Archegonia are found in all land plants, and they are essential for sexual reproduction. Flagellate spermatozoids: Both pteridophytes and mosses have flagellate spermatozoids, which are male reproductive cells with flagella that allow them to swim to the egg. Flagellate spermatozoids are also found in all land plants, and they are essential for sexual reproduction. Therefore, the correct answer is well developed vascular system

1752. In Pinus, the pollen grain has 6 chromosomes then its endosperm will have

• A. 12
• B. 18
• C. 6
• D. 24

Explanation: ( c) : In Pinus, if the pollen grain has 6 chromosomes then its endosperm will also have 6 chromosomes as endosperm and pollen grains are both haploid structures.

1753. A plant having seeds but lacking flowers and fruits belongs to

• A. Pteridophytes
• B. Mosses
• C. Ferns
• D. Gymnosperms

Explanation: A plant having seeds but lacking flowers and fruits belongs to Gymnosperms.Gymnosperms are a group of seed plants that produce naked seeds, meaning that the seeds are not enclosed in a fruit. Gymnosperms do not produce flowers. Some examples of gymnosperms include pine trees, firs, and cedars. Pteridophytes are a group of vascular plants that produce spores, but not seeds. Pteridophytes are commonly known as ferns. Mosses are a group of non-vascular plants that produce spores, but not seeds. Mosses are typically small and grow in moist environments. Ferns are a group of vascular plants that produce spores, but not seeds. Ferns are typically larger than mosses and have leaves. Therefore, the correct answer is Gymnosperm.

1754. Which one of the following is not common between Funaria and Selaginella?

• A. Archegonium
• B. Embryo
• C. Flagellate sperms
• D. Roots

Explanation: Funaria is a moss, while Selaginella is a pteridophyte. Both mosses and pteridophytes have archegonia, embryos, and flagellate sperms. However, only pteridophytes have roots. Archegonium: Archegonia are female reproductive structures that produce eggs. Archegonia are found in all land plants. Embryo: An embryo is a developing plant that is enclosed within a seed or spore. Both mosses and pteridophytes produce embryos. Flagellate sperms: Flagellate sperms are male reproductive cells with flagella that allow them to swim to the egg. Flagellate sperms are found in all land plants. Root: A root is an organ that anchors a plant in the ground and absorbs water and nutrients. Only pteridophytes have roots.Therefore, the correct answer is Root.

1755. The plant group that produces spores and embryo but lacks vascular tissues and seeds is

• A. Pteridophyta
• B. Rhodophyta
• C. Bryophyta
• D. Phaeophyta

Explanation: The plant group that produces spores and embryos but lacks vascular tissues and seeds is Bryophyta. Bryophytes are a group of non-vascular plants that includes mosses, liverworts, and hornworts. Bryophytes are typically small and grow in moist environments. Bryophytes reproduce by releasing spores, which can germinate and develop into new plants. Pteridophyta are a group of vascular plants that produce spores, but not seeds. Pteridophytes are commonly known as ferns. Ferns have leaves and vascular tissues, which allow them to transport water and nutrients throughout the plant. Rhodophyta are a group of red algae. Red algae are unicellular or multicellular organisms that live in water. Red algae do not produce spores or embryos. Phaeophyta are a group of brown algae. Brown algae are unicellular or multicellular organisms that live in water. Brown algae do not produce spores or embryos. Therefore, the correct answer is Bryophyta.

1756. A plant in which sporophytic generation is represented by zygote is

• A. Pinus
• B. Selaginella
• C. Chlamydomonas
• D. Dryopteris

Explanation: Option 1: Pinus Pinus is a gymnosperm, which means that it produces naked seeds. The sporophytic generation in Pinus is the dominant generation, and it is represented by the entire plant, from the roots to the shoots to the cones. The zygote in Pinus is short-lived, and it quickly develops into an embryo. The embryo then develops into a mature sporophyte plant. Option 2: Selaginella Selaginella is a lycopod, which is a type of vascular plant. The sporophytic generation in Selaginella is also the dominant generation, but it is not as dominant as it is in Pinus. The sporophyte in Selaginella is a small, herbaceous plant, and it is found attached to the base of the gametophyte. The zygote in Selaginella develops into an embryo, and the embryo then develops into a mature sporophyte plant. Option 3: Chlamydomonas Chlamydomonas is a type of green alga. The sporophytic generation in Chlamydomonas is very short-lived, and it is represented only by the zygote. The zygote undergoes meiosis to produce haploid spores, and the spores then develop into gametophytes. The gametophytes produce gametes, which fuse to form zygotes. Option 4: Dryopteris Dryopteris is a type of fern. The sporophytic generation in Dryopteris is the dominant generation, and it is represented by the entire plant, from the roots to the shoots to the fronds. The zygote in Dryopteris develops into an embryo, and the embryo then develops into a mature sporophyte plant. Therefore, the correct answer is Chlamydomonas.

1757. Bryophytes are amphibians because

• A. They require a layer of water for carrying out sexual reproduction
• B. They occur in damp places
• C. They are mostly aquatic
• D. All the above

Explanation: (a) : Bryophytes are called amphibians of plant kingdom because they complete their vegetative phase on land but water is necessary for their reproductive phase. Water helps in maturation and dehiscence of sex organs in bryophytes. It also helps in the transfer of sperms to the archegonium that make water essential for completion of life cycle of bryophytes.

1758. The common mode of sexual reproduction in Chlamydomonas is

• A. Isogamous
• B. Anisogamous
• C. Oogamous
• D. Hologamous

Explanation: Isogamy is a type of sexual reproduction in which the gametes are identical in size, shape, and structure.Oogamy is a type of sexual reproduction in which the gametes are different in size, shape, and structure, with the female gamete being larger and non-motile, and the male gamete being smaller and motile. Anisogamy is a type of sexual reproduction in which the gametes are different in size, but similar in shape and structure. Hologamy is a type of sexual reproduction in which the entire organisms fuse to form a zygote. Chlamydomonas is a type of green alga that reproduces sexually through isogamy. This means that the gametes that Chlamydomonas produces are identical in size, shape, and structure. The gametes are also motile, meaning that they can move on their own. When two gametes fuse, they form a zygote, which develops into a new Chlamydomonas cell. Therefore, the correct answer is Chlamydomonas.

1759. The product of conjugation in Spirogyra or fertilization of Chlamydomonas is

• A. Zygospore
• B. Zoospore
• C. Oospore
• D. Carpospore

Explanation: The product of conjugation in Spirogyra or fertilization of Chlamydomonas is a zygospore.A zygospore is a thick-walled resting spore that is formed by the fusion of two gametes. Zygospores are resistant to desiccation and other environmental stressors, and they can remain dormant for long periods of time. When conditions are favorable, the zygospore will germinate and produce new individuals. Zoospores are motile spores that are formed by asexual reproduction. Zoospores have flagella that allow them to swim through water. Zoospores are important for dispersal and for colonizing new habitats. Oospores are non-motile spores that are formed by sexual reproduction in oogamous organisms. Oospores are typically surrounded by a thick wall that protects them from the environment. Oospores are important for overwintering and for surviving harsh conditions. Carpospores are non-motile spores that are formed by sexual reproduction in red algae. Carpospores are typically produced in clusters and are dispersed by water currents. Carpospores are important for dispersal and for colonizing new habitats. Therefore, the correct answer is zygospore.

1760. Moss peristome takes part in

• A. Spore dispersal
• B. Photosynthesis
• C. Protection
• D. Absorption

Explanation: The moss peristome takes part in spore dispersal. The peristome is a ring of teeth that surrounds the opening of the moss capsule. When the capsule is ripe, the peristome teeth open and close in response to changes in humidity. This helps to release the spores from the capsule and disperse them into the air. Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to produce oxygen and glucose. The moss peristome does not play a role in photosynthesis. Protection is the process by which plants defend themselves from herbivores, pathogens, and other environmental stressors. The moss peristome does somehow play a role in protection by helping to keep the spores inside the capsule until they are ready to be dispersed. Absorption is the process by which plants take in water and nutrients from the environment. The moss peristome does not play a role in absorption. Therefore, the correct answer is spore dispersal.