Ch 2 Biological Classification - 1
40 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the composition of fungal cell walls?

  • Cellulose and proteins
  • Chitin and polysaccharides (correct)
  • Lipids and amino acids
  • Pectin and collagen

    • What is the term for fungi that derive their nutrients by absorbing soluble organic matter from dead substrates?

  • Saprophytes (correct)
  • Parasites
  • Mutualists
  • Symbionts

    • What is the network of hyphae called?

  • Fruiting body
  • Fungal tissue
  • Hyphal network
  • Mycelium (correct)

    • What is the term for the process of fusion of two nuclei?

    <p>Karyogamy</p> Signup and view all the answers

    What is the term for fungi that live in association with algae?

    <p>Lichens</p> Signup and view all the answers

    What is the term for the process of reproduction involving fragmentation, fission, and budding?

    <p>Vegetative reproduction</p> Signup and view all the answers

    What is the term for fungi that derive their nutrients by living on living organisms?

    <p>Parasites</p> Signup and view all the answers

    What is the term for the structure in which spores are produced?

    <p>Fruiting body</p> Signup and view all the answers

    What is the primary function of the stiff cellulose plates on the outer surface of dinoflagellates' cell walls?

    <p>Providing structural rigidity</p> Signup and view all the answers

    What is the characteristic of the protein-rich layer in euglenoids' cells?

    <p>Flexible and dynamic</p> Signup and view all the answers

    What is the primary mode of nutrition in euglenoids when they are deprived of sunlight?

    <p>Heterotrophy</p> Signup and view all the answers

    What is the characteristic of the spores formed by slime moulds?

    <p>True walls and extremely resistant</p> Signup and view all the answers

    What is the primary function of the flagella in dinoflagellates?

    <p>Movement and locomotion</p> Signup and view all the answers

    What is the term for the fruiting bodies that contain asci?

    <p>Ascocarps</p> Signup and view all the answers

    Which of the following fungi is used extensively in biochemical and genetic work?

    <p>Neurospora</p> Signup and view all the answers

    What is the characteristic of the pigments present in euglenoids?

    <p>Identical to those present in higher plants</p> Signup and view all the answers

    What is the primary habitat of euglenoids?

    <p>Freshwater environments</p> Signup and view all the answers

    What is the term for the vegetative reproduction process in basidiomycetes?

    <p>Fragmentation</p> Signup and view all the answers

    What is the term for the structure that produces basidiospores?

    <p>Basidium</p> Signup and view all the answers

    What is the characteristic of protozoans?

    <p>Heterotrophic and predatory</p> Signup and view all the answers

    What is the term for fungi that only have asexual or vegetative phases?

    <p>Deuteromycetes</p> Signup and view all the answers

    Which of the following is an example of a basidiomycete?

    <p>Agaricus</p> Signup and view all the answers

    What is the term for the process of fusion of two vegetative or somatic cells of different strains or genotypes?

    <p>Plasmogamy</p> Signup and view all the answers

    Which of the following fungi is an example of an ascomycete?

    <p>Aspergillus</p> Signup and view all the answers

    What was the observation that led to the discovery of viruses?

    <p>They could pass through bacteria-proof filters</p> Signup and view all the answers

    What is the term coined by M.W.Beijerinck for the infectious fluid?

    <p>Contagium vivum fluidum</p> Signup and view all the answers

    What is unique about the genetic material of viruses?

    <p>It is either RNA or DNA, but never both</p> Signup and view all the answers

    What is the function of the protein coat in a virus?

    <p>To protect the nucleic acid</p> Signup and view all the answers

    What is the term for the small subunits that make up the protein coat of a virus?

    <p>Capsomeres</p> Signup and view all the answers

    What is the term for viruses that infect bacteria?

    <p>Bacteriophages</p> Signup and view all the answers

    Who discovered a new infectious agent that was smaller than viruses?

    <p>T.O.Diener</p> Signup and view all the answers

    What is the term for infectious agents that are smaller than viruses?

    <p>Viroids</p> Signup and view all the answers

    What is the characteristic feature of viroids?

    <p>Lack of a protein coat</p> Signup and view all the answers

    Which of the following diseases is caused by prions?

    <p>Both A and B</p> Signup and view all the answers

    What is the role of fungi in lichen symbiosis?

    <p>Providing shelter and absorbing mineral nutrients and water</p> Signup and view all the answers

    Why are lichens good pollution indicators?

    <p>They do not grow in polluted areas</p> Signup and view all the answers

    Who proposed the five kingdom classification of living organisms?

    <p>Whittaker</p> Signup and view all the answers

    What is the characteristic feature of bacteria in terms of metabolic diversity?

    <p>They show the most extensive metabolic diversity</p> Signup and view all the answers

    What is the distribution of bacteria?

    <p>They are cosmopolitan in distribution</p> Signup and view all the answers

    Which of the following kingdoms includes bacteria?

    <p>Monera</p> Signup and view all the answers

    Study Notes

    Dinoflagellates

    • Dinoflagellates are mostly marine and photosynthetic organisms
    • They appear in different colors (yellow, green, brown, blue, or red) depending on the main pigments present in their cells
    • They have a cell wall with stiff cellulose plates on the outer surface
    • Most dinoflagellates have two flagella, one longitudinal and one transverse, in a furrow between the wall plates
    • Red dinoflagellates (e.g., Gonyaulax) can undergo rapid multiplication, causing the sea to appear red (red tides), and releasing toxins that can kill other marine animals like fish

    Euglenoids

    • Euglenoids are mostly fresh water organisms found in stagnant water
    • They have a protein-rich layer called pellicle instead of a cell wall, making their bodies flexible
    • They have two flagella, a short and a long one
    • Although they are photosynthetic in the presence of sunlight, they can behave like heterotrophs by preying on smaller organisms when deprived of sunlight
    • Their pigments are identical to those found in higher plants
    • Example: Euglena

    Slime Moulds

    • Slime moulds are saprophytic protists
    • They move along decaying twigs and leaves, engulfing organic material
    • Under suitable conditions, they form an aggregation called plasmodium, which can grow and spread over several feet
    • During unfavourable conditions, the plasmodium differentiates and forms fruiting bodies bearing spores at their tips
    • The spores have true walls and are extremely resistant, surviving for many years even under adverse conditions

    Protozoans

    • All protozoans are heterotrophs and live as predators or parasites
    • They are believed to be primitive relatives of animals
    • Some are the source of antibiotics, e.g., Penicillium

    Fungi

    • Fungi are cosmopolitan and occur in air, water, soil, and on animals and plants
    • They prefer to grow in warm and humid places
    • Fungi have bodies consisting of long, slender thread-like structures called hyphae
    • The network of hyphae is known as mycelium
    • Some hyphae are continuous tubes filled with multinucleated cytoplasm – these are called coenocytic hyphae
    • Others have septae or cross walls in their hyphae
    • The cell walls of fungi are composed of chitin and polysaccharides
    • Most fungi are heterotrophic and absorb soluble organic matter from dead substrates, hence they are called saprophytes
    • Some fungi are parasites, depending on living plants and animals
    • They can also live as symbionts – in association with algae as lichens and with roots of higher plants as mycorrhiza
    • Reproduction in fungi can take place by vegetative means – fragmentation, fission, and budding
    • Asexual reproduction is by spores, and sexual reproduction is by oospores, ascospores, and basidiospores
    • The various spores are produced in distinct structures called fruiting bodies

    Basidiomycetes

    • Commonly known forms of basidiomycetes are mushrooms, bracket fungi, or puffballs
    • They grow in soil, on logs, and tree stumps, and in living plant bodies as parasites, e.g., rusts and smuts
    • The mycelium is branched and septate
    • Asexual spores are generally not found, but vegetative reproduction by fragmentation is common
    • The sex organs are absent, but plasmogamy is brought about by fusion of two vegetative or somatic cells of different strains or genotypes
    • The resultant structure is dikaryotic, which ultimately gives rise to basidium
    • Karyogamy and meiosis take place in the basidium, producing four basidiospores
    • The basidiospores are exogenously produced on the basidium
    • The basidia are arranged in fruiting bodies called basidiocarps

    Deuteromycetes

    • Commonly known as imperfect fungi because only the asexual or vegetative phases of these fungi are known
    • When the sexual forms of these fungi were discovered, they were moved into classes they rightly belong to
    • It is also possible that the asexual and vegetative stage have been given one name (and placed under deuteromycetes) and the sexual stage another (and placed under another class)

    Viruses

    • Viruses are obligate parasites
    • In addition to proteins, viruses also contain genetic material, which could be either RNA or DNA
    • No virus contains both RNA and DNA
    • Viruses are nucleoproteins, and the genetic material is infectious
    • Viruses cause diseases like mumps, small pox, herpes, influenza, and AIDS in humans
    • In plants, symptoms can be mosaic formation, leaf rolling and curling, yellowing, and vein clearing, dwarfing, and stunted growth

    Viroids

    • Viroids are infectious agents that are smaller than viruses and cause diseases like potato spindle tuber disease
    • They lack the protein coat that is found in viruses
    • The RNA of the viroid is of low molecular weight

    Prions

    • Prions are infectious agents consisting of abnormally folded protein
    • They are similar in size to viruses
    • They cause diseases like bovine spongiform encephalopathy (BSE) in cattle and its analogous variant Creutzfeldt-Jakob disease (CJD) in humans

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser