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Medical
208 Views   |  

The chief water conducting elements of xylem in gymnosperms are

  • Option 1)

    vessels

  • Option 2)

    fibres

  • Option 3)

    transfusion tissue

  • Option 4)

    trancheids

 
  Food conduction in gymnosphere, food conduction in angiosperm - In gymnosperms and pteridophytes, sieve tubes are absent and sieve cells are arranged irregularly. So conduction of food takes place in zig-zag manner. In angiosperm, food conduction is erect and efficient. Food conduction is bidirectional in sieve tube, sieve tube is an example of living syncyte -   Tracheids are chief water...
Medical
210 Views   |  

Ovary is half-inferior in the flowers of:

  • Option 1)

    guava

  • Option 2)

    plum

  • Option 3)

    brinjal

  • Option 4)

    cucumber

 
  Position of floral parts on thalamus - Hypogyny - ovary is at the top and separable from thalamus. ovary is superior and convex eg: Brassica & malva perigyny: ovary is half superior and half inferior. example, rose. Epigyny - calyx & corolla arise from the upperside of ovary & Ovary is completely surrounded by or fused by thalamus. Ovary is inferior. eg: luffa , Aster -     Option...
Medical
105 Views   |  

In unilocular ovary with a single ovule the placentation is:

 

  • Option 1)

    Marginal

  • Option 2)

    Basal

  • Option 3)

    Free central

  • Option 4)

    Axile

 
  Basal placenta - Ovary is unilocular and placenta develops at the base of ovary on thalamus bears a single ovule. - wherein Ex. Wheat, Maize, Aster       Option 1) Marginal This solution is incorrect  Option 2) Basal This solution is correct  Option 3) Free central This solution is incorrect  Option 4) Axile This solution is incorrect 
Medical
133 Views   |  

Which one of the following statements about certain given animals is correct?

  • Option 1)

    Round worms (Aschelminthes) pseuocoelomates

  • Option 2)

    Molluscs are acoelomates

  • Option 3)

    Insects are pseudocoelomates

  • Option 4)

    Flat worms (Platyhelminthes) are coelomates

 
  Phylum Aschelminthes (roundworm) - Body is circular in cross-section. They are free-living, aquatic and terrestrial or parasitic. Bilateral symmetry, triploblastic and pseudocoelomates. - wherein Eg. Ascaris, Wucheria, Ancylostoma.     Pseudocoelomates - Body cavity is not lined by mesoderm, instead, they are present as scattered pouches between ectoderm and endoderm. - wherein Eg....
Medical
110 Views   |  

One example of animals having a single opening to the outside that serves both as mouth as well as anus is:

  • Option 1)

    Octopus

  • Option 2)

    Asterias

  • Option 3)

    Ascidia

  • Option 4)

    Fasciola

 
  Phylum Platyhelminthes (Flat Worms) - Free living, commensal or parasite with dorsoventrally flattened body, bilaterally symmetrical, triploblastic and acoelomate. - wherein Eg. Taenia, Fasciola    Fasclola (Platyhelminthea) has single opening for both ingestion and excretion Option 1) Octopus This is incorrect option Option 2) Asterias This is incorrect option Option 3) Ascidia This is...
Medical
93 Views   |  

Which one of the following kinds of animals are triploblastic?

  • Option 1)

    Flat worms

  • Option 2)

    sponges

  • Option 3)

    Ctenophores

  • Option 4)

    Corals

 
  Phylum Platyhelminthes (Flat Worms) - Free living, commensal or parasite with dorsoventrally flattened body, bilaterally symmetrical, triploblastic and acoelomate. - wherein Eg. Taenia, Fasciola     Option 1) Flat worms This is correct option Option 2) sponges This is incorrect option Option 3) Ctenophores This is incorrect option Option 4) Corals This is incorrect option
Medical
182 Views   |  

Male and female gametophytes are independent and free-living in:

  • Option 1)

    Mustard 

  • Option 2)

    Castor 

  • Option 3)

    Pinus 

  • Option 4)

    Sphagnum

 
  Bryopsida / Mosses - Gamatophytic plant body is thalloid protonema and leafy with obliquely septate rhizoids and elaters absent in sporophytic stage. - wherein Eg. Sphagnum, Funaria     Haplo-diplontic life cycle - Sporophyte and gametophyte both are photosynthetic and free living. - wherein Eg  All bryophytes and pteridophytes some brown algae (Laminaria). Ectocarpus, some green algae (ulva...
Medical
109 Views   |  

Some hyperthermophilic organisms that grow in highly acidic (PH2) habitats belong to the two groups:

  • Option 1)

    Eubacteria and archaea

  • Option 2)

    Cyanobacteria and diatoms 

  • Option 3)

    Protists and mosses 

  • Option 4)

    Liverworts and yeasts 

 
  Thermoacidophiles - Chemosynthetic Aerobes or anaerobes Gram negative bacteria They oxidised or reduced sulphur Grow in high temperature and high acidic condition (pH 1 – 4)and found in hot sulphur springs. - wherein Eg. Thermo plasma, thermo protein.     Archaebacteria - Live in harsh habitats. Cell walls lack muramic acid and peptidoglycan. Branched lipids having Phytanyl side groups...
Medical
135 Views   |  

Algae have cell wall made up of:

  • Option 1)

    cellulose, galactans and mannans 

  • Option 2)

    hemicellulose, pectins and proteins 

  • Option 3)

    pectins, cellulose and proteins 

  • Option 4)

    cellulose, hemicellulose and pectins 

 

option 1. cellulose galactans and mannans and also composed of pectin

 

Medical
87 Views   |  

Virus envelope is known as:

  • Option 1)

    Capsid

  • Option 2)

    Virion

  • Option 3)

    Nucleoprotein 

  • Option 4)

    Core

 
As learnt in Composition of virus - Envelope - Outer loose covering with peplomer proteins. Capsid - Protein covering around the genetic material made of capsomeres. Nucleoid - Either DNA or RNA. -    Virus envelope is known as Capsid. Option 1) Capsid This option is correct. Option 2) Virion This option is incorrect. Option 3) Nucleoprotein  This option is incorrect. Option 4) Core This...
Medical
95 Views   |  

Membrane-bound organelles are absent in:

  • Option 1)

    Saccharomyces

  • Option 2)

    Streptococcus

  • Option 3)

    Chlamydomonas

  • Option 4)

    Plasmodium

 
As learnt in Coccus Bacteria - About spherical and always non flagellate. - wherein Micrococcus, Diplococcus, Streptococuus etc.    Membrane bound organelles are absent in prokaryotes (bacteria). Option 1) Saccharomyces This option is incorrect. Option 2) Streptococcus This option is correct. Option 3) Chlamydomonas This option is incorrect. Option 4) Plasmodium This option is incorrect.
Medical
86 Views   |  

Single-celled eukaryotes are included in:

  • Option 1)

    Protista 

  • Option 2)

    Fungi 

  • Option 3)

    Archaea 

  • Option 4)

    Monera 

 
As learnt in Kingdom Protista - Unicellular eukaryotic. Mostly aquatic. Well define nucleus present Various membrane bound organelles present Flagella and cilia, if present have (9+2) pattern of micro tubular stands. Reproduction is asexual and sexual. Autotrophic, parasitic and heterotrophic. - wherein Classified into three type Photosynthetic protists Consumer decomposer protists...
Medical
148 Views   |  

If for some reason our goblet cells are non functional this will adversely affect:

  • Option 1)

    production of somatostatin

  • Option 2)

    secretion of sebum from the sebaceous glands

  • Option 3)

    maturation of sperms

  • Option 4)

    smooth movement of food down the intestine

 
As we learnt in Goblet Cells - The intestinal mucosal epithelium has goblet cells which secrete mucus. - wherein The secretions of the brush border cells of the mucosa alongwith the secretions of the goblet cells constitute the intestinal juice or succus entericus    Mucus helps is smooth movement of food down the intestine Option 1) production of somatostatin Incorrect Option 2) secretion of...
Medical
138 Views   |  

Which one of the following symbols and its representation, used in human pedigree analysis is correct?

  • Option 1)

       = mating between relatives

  • Option 2)

    \bigcirc  = unaffected male

  • Option 3)

    \square  = unaffected female

  • Option 4)

    \blacklozenge  = male affected

 
As learnt in Pedigree analysis in human genetics - In human genetics, the pedigree study provides a strong tool, which is utilised to trace the inheritance of a specific trait, abnormality or disease. - wherein Some of the important symbols used in the pedigree analysis are shown.     Option 1)    = mating between relatives This option is correct Option 2)   = unaffected male This option is...
Medical
144 Views   |  

Darwin's finches are a good example of:

  • Option 1)

    Industrial melanism

  • Option 2)

    Connecting link

  • Option 3)

    Adaptive radiation

  • Option 4)

    Convergent evolution

 
As learnt in Darwin's Finches - Another breed of inhabitants found in Galapagos islands. - wherein Darwin grouped the finches into 6 types: 1. Large ground 2. Cactus ground 3. Vegetarian tree 4. Insectivorous 5. Warbler 6. Wood pecker    Darwin's finches are example of adaptive radiation, which gives rise to new species. Option 1) Industrial melanism This option is incorrect Option...
Medical
138 Views   |  

Satelite DNA is useful tool in:

  • Option 1)

    organ transplantation

  • Option 2)

    sex determination

  • Option 3)

    forensic science

  • Option 4)

    genetic engineering

 
As learnt in Application of DNA fingerprinting - Since DNA from every tissue (Eg: blood,hair follicle, skin, bone, saliva, sperm etc.) from an individual show the same degree of polymorphism, they become very useful identification tool in forensic application. -    Satellite DNA is tandemly repeated, non-coding DNA, which are used in forensic applications. Option 1) organ transplantation This...
Medical
113 Views   |  

Select the two correct statements out of the four (a-d) given below about lac operon.

(i) Glucose or galactose may bind with the repressor and inactivate it

(ii) In the absence of lactose the repressor binds with the operator region

(iii) The z-gene codes for permease

(iv) This was elucidated by Francois Jacob and Jacque Monod

The correct statements are: 

  • Option 1)

    (ii) and (iii)

  • Option 2)

    (i) and (iii)

  • Option 3)

    (ii) and (iv)

  • Option 4)

    (i) and (ii)

 
As learnt in The lac operon - In lac operon, a polycistronic structural gene is regulated by a common promoter and regulatory genes.  - wherein Such arrangements are very common in bacteria and is referred to as operon.      Lac operon was proposed by Jacob and Monod. When glucose is present and lactose is absent, the repressor binds with the operator region and prevents transcription. Option...
Medical
131 Views   |  

The one aspect which is not a salient feature of genetic code, is its being:

  • Option 1)

    degenerate

  • Option 2)

    ambiguous 

  • Option 3)

    universal

  • Option 4)

    specific

 
As learnt in Silent features og Genetic code - One codon codes for only one amino acid hence it is unambigous and specific. -     Option 1) degenerate This option is incorrect Option 2) ambiguous  This option is correct Option 3) universal This option is incorrect Option 4) specific This option is incorrect
Medical
240 Views   |  

Which one of the following does not follow the central dogma of molecular biology?

  • Option 1)

    Pea

  • Option 2)

    Mucor

  • Option 3)

    Chlamydomonas

  • Option 4)

    HIV

 
As we learnt in  Crick's Proposal of Central Dogma - The double helix structure of DNA and its simplicity in explaining the genetic implication became revolutionary. - wherein Very soon, Francis Crick proposed the central dogma in molecular biology which states that the genetic information flow from DNA → RNA → Protein.     HIV is a retrovirus in which the flow of information is from Option...
Medical
189 Views   |  

Select the correct statement from the ones given below with respect to dihybrid cross.

  • Option 1)

    Tightly linked genes on the same chromosome show higher recombination

  • Option 2)

    Genes far apart on the same chromosome show very few recombinations

  • Option 3)

    Genes loosely linked on the same chromosome show similar recombination the tightly linked ones

  • Option 4)

    Tightly linked genes on the same chromosome show very few recombinations

 
As learnt Recombination - Morgan experimented and found that when the two genes in a hybrid cross situated on same chromosone, the proportion of parental gene combination were much higher than the non-parental type.. Based on this observation, he coined the term recombination. - wherein To describe the generation of non-parental gene combinations       Cross B in Morgan's Experiment - In cross...
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