Diversity in The Living World MCQ Quiz - Objective Question with Answer for Diversity in The Living World - Download Free PDF

The correct answer is Asexual reproduction

Explanation:

• Bryophytes are a group of non-vascular plants that include mosses, liverworts, and hornworts. They are characterized by their simple structure and life cycle, which involves alternation of generations.
• In bryophytes, gemmae are small, multicellular structures that serve as a means of vegetative (asexual) reproduction.
• Asexual reproduction in Marchantia (Liverwort) takes place by fragmentation of thalli, or by the formation of specialized structures called gemmae (sing. Gemma).
• In Marchantia, the plant body consists of a dorsiventrally flattened, prostrate and dichotomously branched thallus.
• The thalli are conspicuous, apex of each thallus is notched.
• Along the mid-rib are present characteristic, prominent goblet or cup-shaped structures, the gemma cups, with smooth, dentate or frilled margins.
• These cups enclose asexual reproductive bodies called gemma.
• Gemmae are green, multicellular, asexual buds, which develop in small receptacles called gemma cups located on thalli.
• The gemmae become detached from the parent body and germinate to form new individuals.

Fig: A liverwort – Marchantia (a) Female thallus (b) Male thallus

The correct answer is A and C Only

Concept:

• Echinoderms have an endoskeleton of calcareous ossicles and, hence, the name Echinodermata (Spiny bodied)
• All are marine with organ-system level of organisation.
• The adult echinoderms are radially symmetrical but larvae are bilaterally symmetrical.
• They are triploblastic and coelomate animals.
• Digestive system is complete with mouth on the lower (ventral) side and anus on the upper (dorsal) side.
• The most distinctive feature of echinoderms is the presence of water vascular system which helps in locomotion, capture and transport of food and respiration.
• An excretory system is absent. Sexes are separate.
• Reproduction is sexual. Fertilisation is usually external.
• Development is indirect with free-swimming larva.
• Examples: Asterias (Star fish), Echinus (Sea urchin), Antedon (Sea lily), Cucumaria (Sea cucumber) and Ophiura (Brittle star).

Explanation:

• Role of the Water Vascular System:
  • Respiration: The water vascular system facilitates gaseous exchange by circulating water through structures like tube feet and dermal branchiae, allowing oxygen uptake and carbon dioxide release.
  • Locomotion: The tube feet, powered by the water vascular system, create suction to help the organism move and adhere to surfaces. This is critical for activities like crawling and climbing in their marine environment.
  • Capture and Transport of Food: In some echinoderms, the water vascular system aids in handling food. For example, the tube feet help starfish pry open bivalve shells or pass food particles toward the mouth

The correct answer is A-IV, B-III, C-I, D-II

Explanation:

• Pteridophytes (A-IV):
  • Pteridophytes are vascular plants that reproduce via spores and do not produce seeds or flowers.
  • An example of a pteridophyte is Salvinia, a water fern commonly found in aquatic habitats.
• Bryophytes (B-III):
  • Bryophytes are non-vascular plants that thrive in moist environments and reproduce via spores.
  • Polytrichum, a genus of mosses, is a well-known example of bryophytes.
• Angiosperms (C-I):
  • Angiosperms are flowering plants that produce seeds enclosed in fruits. They represent the most advanced and diverse group of plants.
  • Salvia, a genus of flowering plants, is a representative example of angiosperms.
• Gymnosperms (D-II):
  • Gymnosperms are seed-producing plants that do not produce flowers or fruits. Their seeds are "naked" or exposed.
  • Ginkgo, often referred to as a "living fossil," is a classic example of gymnosperms.

The correct answer is Seeds are naked

Explanation:

• Gymnosperms are a group of seed-producing plants that include conifers, cycads, Ginkgo, and gnetophytes.
• The term "gymnosperm" comes from Greek words meaning "naked seed"
• The gymnosperms are plants in which the ovules are not enclosed by any ovary wall and remain exposed, both before and after fertilisation.
• The seeds that develop post-fertilisation, are not covered, i.e., are naked.
• Gymnosperms are vascular plants, meaning they have specialized tissues for transporting water and nutrients.
• They are predominantly woody trees and shrubs and are adapted to survive in various climatic conditions.

Other Options

• Seeds are enclosed in fruits: This statement refers to angiosperms, which are flowering plants. In angiosperms, seeds develop inside fruits formed from the ovary after fertilization.
• Seeds are absent: Gymnosperms are seed-producing plants.Plants without seeds are typically non-vascular plants like mosses or vascular plants like ferns, which reproduce via spores.
• Gymnosperms have flowers for reproduction: Flowers are a characteristic feature of angiosperms, not gymnosperms.

The correct answer is Both A and R are true, and R is the correct explanation of A

Concept:

• Chordates are animals that possess, at some stage of their life cycle, a notochord, a dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail.
• The notochord is a flexible rod that provides support in all embryonic and some adult chordate animals.
• In vertebrates, the notochord is present during embryonic development but is later replaced by the vertebral column (spine) as the main structural support.

Explanation:

• Assertion (A): The statement "All vertebrates are chordates but all chordates are not vertebrates" is true. This is because vertebrates form a subgroup within the larger group of chordates.
• Reason (R): The statement "The members of subphylum Vertebrata possess a notochord, during the embryonic period, the notochord is replaced by a cartilaginous or bony vertebral column in adults" is also true. Vertebrates initially develop a notochord in their embryonic stage which is later replaced by a vertebral column made of cartilage or bone.

 The Reason (R) correctly explains the Assertion (A) because it details a key characteristic that distinguishes vertebrates from other chordates – the replacement of the notochord by a vertebral column.

The correct answer is a - iv, b - iii, c - ii, d - i.

Key Points

• Blue-green Algae (Cyanobacteria)
  • Blue-green algae are actually bacteria and are also known as Cyanobacteria.
  • They are photosynthetic organisms and can live in a wide variety of environments, including freshwater, seawater, damp soil, or rocks.
  • Cyanobacteria are known for their significant contribution to the Earth's oxygen atmosphere.
  • They can exist as single cells or can form colonies.
• Red Algae (Rhodophyta)
  • Red algae, often called Rhodophyta, have been identified as one of the oldest groups of eukaryotic algae.
  • They are mostly found in the warmer waters of the ocean.
  • Red algae are of great economic value because of their use in the production of agar and carrageenan, substances used as thickening agents in various food products.
  • Their red colour is due to the pigment, phycoerythrin.
• Green Algae (Chlamydomonas)
  • Green algae are a diverse group of algae from which plants evolved. Chlamydomonas is a genus of unicellular green algae.
  • Chlamydomonas species are widely distributed worldwide and are found in soil and freshwater.
  • They have two flagella that allow them to move.
  • They are known for their green colour due to the presence of chlorophyll.
• Brown Algae (Sargassum)
  • Brown algae are the most complex type of algae; many are seaweeds.
  • Sargassum is a brown algae, known for forming massive floating forests in the ocean.
  • It is primarily marine and is found in warm-temperate and tropical oceans.
  • They provide important ecological functions such as providing habitats for a wide variety of marine species.
  • The brown colour is due to the presence of a pigment called fucoxanthin, which masks the green colour of chlorophyll.

The correct answer is Collar cells.

 Key Points

• The body of sponges (poriferans) has several minute pores called ostia through which the water enters into the central cavity, spongocoel.
• The flagellated cells called choanocytes (collar cells) line the spongocoel.
• These cells generate a flow of water and the water current helps in food gathering, respiratory exchange and removal of waste.
• The water finally goes out of the body through a large pore called osculum. (Plural: oscula).
• The body wall of the sponge is composed of two layers: outer pinacoderm and inner choanoderm. In between these two layers, mesenchyme is present with various mesenchymal cells.

Additional Information

• Somatic cells make up the connective tissue, skin, blood, bones and internal organs.
• White blood cells are made in the bone marrow. They are stored in your blood and lymph tissues.
• These sex cells are also called reproductive cells or gametes. Sperm cells are produced in men's testicles and egg cells are produced in women's ovaries

The correct answer is Rhodophyceae.Key Points

• Red algae:-
  • It is a type of marine algae that are predominantly red in color due to the presence of pigments such as phycoerythrins and phycocyanins.
  • They are found in both tropical and temperate waters and play an important role in marine ecosystems as primary producers and as a food source for herbivorous marine animals.
  • Some species of red algae are also used by humans for various purposes such as food, medicine, and cosmetics.
  • Red algae are known for their ability to survive in extreme environments such as deep-sea hydrothermal vents and polar regions.

Additional Information

• Chlorophyceae:
  • This is a class of green algae that are mostly freshwater species and are commonly found in ponds, lakes, and streams.
• Liverwort:
  • This is a type of non-vascular plant that grows in damp habitats such as forests, bogs, and riverbanks.
  • They are commonly found in temperate and tropical regions and play an important role in soil formation and nutrient cycling.
• Phaeophyceae:
  • This is a class of brown algae that are predominantly marine and are commonly found in temperate and cold waters.
  • They are important primary producers in coastal ecosystems and are also used by humans for food and other purposes.

The correct answer is Marchantia.Key Points

• Liverworts:-
  • These are non-vascular plants that belong to the phylum Hepatophyta.
  • The umbrella-shaped structures that raise gametangia above the main gametophyte body are known as archegoniophores.
  • These archegoniophores are found in the genus Marchantia.
• Marchantia:-
  • It is a genus of liverworts, which are a type of non-vascular plant often found in moist and damp environments.
  • Liverworts belong to the division Marchantiophyta and are some of the earliest land plants to have evolved.
  • Marchantia liverworts are small, flat, and leafy plants that typically grow in low, spreading mats.
  • They have a distinctive appearance with flattened, lobed structures that resemble tiny leaves.

Additional Information

• Polytrichum:-
  • It​ also known as haircap moss, is a type of moss that forms dense cushions or tufts in moist habitats.
• Funaria:-
  • It​ is also known as cord moss, is a common type of moss that is found in moist, shaded habitats.
• Sphagnum:-
  • It is  also known as peat moss, is a type of moss that is found in wetlands and bogs and is known for its ability to store water.

Concept:

• There are innumerable species of plants and animals and other organisms inhabiting the surface of the earth.
• To identify and study these species, it is necessary to develop a mechanism that has a universal application.
• Different life forms are identified and classified into different groups which helps in their study.

Explanation:

Different Systems of Classification - 

• Two Kingdom System of Classification:
  • Carl Linnaeus divided all the life forms present on the earth into two groups based on their mode of nutrition.
  • He gave the two Kingdom System which includes - Kingdom Plantae and Kingdom Animalia.
  • However, this system of classification was inadequate due to the vast majority of organisms found on earth.
• Five Kingdom System of Classification:
  • R.H. Whittaker proposed the Five Kingdom System of Classification.
  • According to R.H. Whittaker's Five Kingdom system, the living organisms are divided into the following Kingdoms - 

•    Kingdom Monera includes unicellular prokaryotic organisms. Eg: Pseudomonas
• Kingdom Protista includes unicellular eukaryotic organisms. Eg: Euglena
• Kingdom Plantae includes multicellular eukaryotic organisms. Includes autotrophs, semi-autotrophs, and insectivorous plants.
• Kingdom Fungi include multicellular eukaryotic organisms (except for yeast which is unicellular). These are mainly heterotrophs. E.g.- Saccharomyces cerevisiae
• Kingdom Animalia includes multicellular eukaryotes that are heterotrophs. These organisms have adapted to holozoic nutrition. E.g.- Human beings

So from the above-given information, the correct answer is option 1.   

The correct answer is Species.

Key Points

• Species are the fundamental classification unit.
  • A Species is a group of organisms with similar Morphologies that are capable of Mating.
  • The Basic unit of Classification and Taxonomic order for an individual in biology is a species, which is also a part of Biodiversity.
  • Species is the largest group of creatures in which any two compatible Partners, typically through sexual reproduction, can produce fertile offspring.
  • A Species can also be distinguished by its karyotype, DNA sequencing, outward appearance, behavioral patterns, and ecological niche. Because it is impossible to assess the development of fossils, paleontologists also use the chronospecies concept.
  • All species, with the exception of viruses, have a two-part name called a "binomial." The first part is the genus to which the species belongs.

Additional Information

• Bacteria, Archaea, Protozoa, Chromista, Plantae, Fungi, and Animalia are the 7 different kingdoms.
  • A Genus is a taxonomic category ranking used in biological classification that is below family and above species.

The correct answer is i - b, ii - a, iii - d, iv - c. Key Points

• Chlorophyceae:-
  • It is a class of green algae, distinguished mainly on the basis of ultrastructural morphology.
  • They are usually green due to the dominance of pigments chlorophyll a and chlorophyll b.
  • The chloroplast may be discoid, plate-like, reticulate, cup-shaped, spiral- or ribbon-shaped in different species.
  • Most of the members have one or more storage bodies called pyrenoids located in the chloroplast.
  • Pyrenoids contain protein besides starch. Some green algae may store food in the form of oil droplets.
• Phaeophyceae:-
  • It also known as brown algae, is a class of multicellular algae that are found primarily in marine environments.
  • They are distinguished by their brown color, which is due to the presence of the pigment fucoxanthin.
  • Brown algae range in size from microscopic filaments to giant kelp forests that can reach over 60 meters in length.
• Cyanophyceae:-
  • It is known as Cyanobacteria, is a class of prokaryotic organisms that obtain energy via photosynthesis.
  • It is known as Blue-green algae.
  • They are considered to be the oldest form of life on Earth, with fossils dating back over 3.5 billion years.
  • Cyanobacteria are found in a wide variety of habitats, including freshwater, marine, and terrestrial environments.
• Rhodophyceae:-
  • It also known as red algae, is a class of eukaryotic algae that are found primarily in marine environments.
  • They are distinguished by their red color, which is due to the presence of the pigment phycoerythrin.
  • Red algae range in size from microscopic filaments to large, complex seaweeds.

The correct answer is Platyhelminthes.Key Points

• Platyhelminthes are also known as flatworms.
• Flatworms have unsegmented, bilaterally symmetrical, soft bodies, with a triploblastic construction (comprising three layers of cells) and a lacking coelom, skeleton, and anus.
• Example includes Planaria, Liver fluke (Fasciola hepatica), and Tapeworm.

Additional Information

• Cnidaria includes jellyfish, corals, and sea anemones.
  • They have radial symmetry, a single body opening, and stinging cells called cnidocytes.
• Ctenophora includes comb jellies.
  • They have radial symmetry and cilia for movement but also have a complete digestive system.
• Porifera includes sponges.
  • They have asymmetrical or radial symmetry, no true tissues, and filter food through pores in their bodies.

The correct answer is Aschelminthes. Key Points

• ​Roundworms are the popular name for Aschelminthes.
• They are distinguished by having a pseudocoelom.
• They either live freely or are parasites.
• They can be found on plants, animals, humans, and even in freshwater and soil.
• In the human intestine, Ascaris is discovered to exist as an endoparasite.
• The body is triploblastic and bilaterally symmetric.
• The body is long, slender, and not segmented; it tapers out at the end.
• There is no evidence of metameric segmentation.
• Males are often smaller than females since they are dioecious.
• Their bodies are organised on an organ-system level.​

Additional Information

• Platyhelminthes:
  • The flatworms, also known as platyhelminths, are a phylum of soft-bodied, relatively uncomplicated bilaterian invertebrates.
  • They are bilaterally symmetrical, triploblastic, and acoelomate.
  • They could be parasites or free-living beings.
• Ctenophores:
  • Sea waters are home to a phylum of marine invertebrates known as comb jellies, or Ctenophora.
  • They have two embryonic layers, the ectoderm and endoderm, making them diploblastic.
  • They lack a bodily cavity since they are acoelomates.
  • Ctenophores are symmetrical in all directions.
• Mollusca:
  • After Arthropoda, Mollusca is the second-largest phylum of invertebrate animals.
  • Organ system level organization can be seen in them.
  • A cavity exists in their body.
  • The skull, visceral mass, muscular foot, and mantle are the different parts of the body.
  • Tentacles and complex eyes make up the head.
  • The body has a calcareous shell covering it.