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Medical
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The genotype of a plant showing the dominant phenotype can be determined by:

  • Option 1)

    test cross

  • Option 2)

    dihybrid cross

  • Option 3)

    pedigree analysis

  • Option 4)

    back cross

 
As learnt Test Cross - To determine the genotype of a tall plant at F2 , Mendel crossed the tall plant from F2 with a dwarf plant. - wherein This is called test cross.     Option 1) test cross This option is correct Option 2) dihybrid cross This option is incorrect Option 3) pedigree analysis This option is incorrect Option 4) back cross This option is incorrect
Medical
100 Views   |  

Which one oft he following cannot be explained on the basis of Mendel's Law of Dominance?

  • Option 1)

    The discrete unit controlling a particular character is called a factor

  • Option 2)

    Out of one pair of factors one is dominant, and the other recessive

  • Option 3)

    Alleles do not show any blending and both the characters recover as such in F_{2} generation.

  • Option 4)

    Factors occur in pairs

 
As learnt Recessive gene or factor - In a pair of dissimilar factors, one factor is recessive and other is dominant over other - wherein In Mendel's experiment, T(tallness) is dominant over t (dwarfness) That is recessive    AND Dominant gene or factor - In a pair of dissimilar factors, one dominates the other (as in F1) and hence called dominant factor. - wherein eg: phenotype of...
Medical
117 Views   |  

Genetic engineering has been successfully used for producing.

  • Option 1)

    transgenic mice for testing safety of polio vaccine before use in humans

  • Option 2)

    transgenic models for studying new treatment for certain cardiac diseases

  • Option 3)

    transgenic cow - roise which produces high fat milk for making ghee

  • Option 4)

    animals like bulls for farm work as they have the super power

 
As learnt in Principles - Biotechnology deals in two principles - 1- Maintenance of microbial contamination free (sterile) surrounding in chemical engineering (old biotechnology). Ex. production of ethanol by fermentation 2 - Genetic Engineering - It is also known as Recombinant DNA Technology or RDI.   - wherein Only desired organism grow under sterile condition to produce large amount of...
Medical
100 Views   |  

Some of the characteristics of Bt cotton are:

  • Option 1)

    long fibre and resistance to aphids

  • Option 2)

    medium yield, long fiber and resistance to beetle pests

  • Option 3)

    high yield and production of toxic proteins crystals which kill dipteran pests

  • Option 4)

    high yield and resistance to bollworms

 
As learnt in Genetically modified crops (GMOs) - Are transgenic crops which contain and express one or more useful foreign genes or transgenes. The food which is prepared by GMC is called genetically modified food. - wherein Ex. BT Cotton, Flavre-Savre Tomato. Transgenic plants also known as bioreactors or factories to produce specific products.    Bt cotton is a genetically modified crop...
Medical
91 Views   |  

The genetically - modified (GM) brinjal in India has been developed for:

  • Option 1)

    insect - resistance

  • Option 2)

    enhancing shelf life

  • Option 3)

    enhancing mineral content

  • Option 4)

    drought -resistance

 
As learnt in Genetically modified crops (GMOs) - Are transgenic crops which contain and express one or more useful foreign genes or transgenes. The food which is prepared by GMC is called genetically modified food. - wherein Ex. BT Cotton, Flavre-Savre Tomato. Transgenic plants also known as bioreactors or factories to produce specific products.    GM brinjal has Cry-Lac gene to make it...
Medical
166 Views   |  

Stirred tank bioreactors have been designed for

  • Option 1)

    addition of preservatives to the product

  • Option 2)

    purification of the product

  • Option 3)

    ensuring anaerobic conditions in the culture vessel

  • Option 4)

    availability of oxygen throughout the process

 
As learnt in Bioreactors - Bioreactors are stirrer cylindrical tanks. The stirrer provides movement, even mixing and O2 availability throughout the bioreaction. - wherein Bioreactors can be 100 to 1000 lt for large production.     Option 1) addition of preservatives to the product This option is incorrect Option 2) purification of the product This option is incorrect Option 3) ensuring...
Medical
102 Views   |  

Restriction endonucleases are enzymes which

  • Option 1)

    make cuts at specific positions within the DNA molecule

  • Option 2)

    recognize a specific nucleotide sequence for binding of DNA ligase

  • Option 3)

    restrict the action of the enzyme DNA Polymerase

  • Option 4)

    remove nucleotides from the ends of the DNA molecule

 
As learnt in Restriction Endonuclease - These enzymes cleave DNA only within or near the specific base sequence. These sequences are called as recognition sites. They are of three types RE- I, RE-II and RE-III. - wherein 1st Restriction enzyme (Hind II) was used in RDT.      Option 1) make cuts at specific positions within the DNA molecule This option is correct Option 2) recognize a specific...
Medical
145 Views   |  

DNA or RNA segment tagged with a radioactive molecule is called.

  • Option 1)

    Vector

  • Option 2)

    Probe

  • Option 3)

    Clone

  • Option 4)

    Plasmid

 
As learnt in Probe - Probe are short (20-25 nucleotides) single-stranded radiolabeled sequence complementary to a target sequence. - wherein Are used is Southern Blotting.    and Southern Blotting - This technique is developed by Edward Southern, in which DNA fragments from agarose gel are transfered to nylon membrane and then hybridization with a radio labeled probe. - wherein This technique...
Medical
105 Views   |  

Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzyme?

  • Option 1)

    5'..................... CGTTCG.............3'

    3'......................ATGGTA...............5'

  • Option 2)

    5'..................... GATATG.............3'

    3'......................CTACTA...............5'

  • Option 3)

    5'..................... GAATTC.............3'

    3'......................CTTAAG...............5'

  • Option 4)

    5'..................... CACGTA.............3'

    3'......................CTCAGT...............5'

 
As learnt in Palindromic sequence for ECORI - - wherein produce sticky ends     Option 1) 5'..................... CGTTCG.............3' 3'......................ATGGTA...............5' This option is incorrect Option 2) 5'..................... GATATG.............3' 3'......................CTACTA...............5' This option is incorrect Option 3) 5'........................
Medical
96 Views   |  

Which one of the following is used as a vector for cloning genes into higher organisms?

  • Option 1)

    Baculoviruses

  • Option 2)

    Salmonella typhimurium

  • Option 3)

    Rhizopus nigricans

  • Option 4)

    Retrovirus

 
As learnt in Vectors - The vectors are DNA molecules that can carry a foreign DNA segment and replicate inside the host cell. Vectors may be plasmids; bacteriophage, cosmids, phagemids, yeast artificial chromosomes (YAC), Bacterial Artificial Chromosomes (BAC); transposones, shuttle vectors and virus. - wherein Vectors carry inserted DNA from one host to another host.    Vectors used for...
Medical
225 Views   |  

Wind-pollinated flowers are

  • Option 1)

    small, brightly coloured producing larage number of pollen grains

  • Option 2)

    small, producing larage number of dry pollen grains

  • Option 3)

    large producing abundant nectar and pollen

  • Option 4)

    small, producing nectar and dry pollen

 
As we discussed in concept Wind as an Agent of Pollination - Wind pollination also requires that the pollen grains are light and non-sticky so that they can be transported in wind currents. They often possess well-exposed stamens so that the pollens are easily dispersed into wind currents. Stigma is large and often-feathery to easily trap air-borne pollen grains. They have a single ovule in...
Medical
306 Views   |  

Which one of the following statements about morula in humans is correct?

  • Option 1)

    It has almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA

  • Option 2)

    It has far less cytoplasm as well as less DNA than in an uncleaved zygote

  • Option 3)

    It has more or less equal quantity of cytoplasm and DNA as in uncleaved zygote

  • Option 4)

    It has more cytoplasm and more DNA than an uncleaved zygote

 
As we discussed in concept Cleavage - The mitotic division or cleavage starts as the zygote moves through the isthmus of the oviduct towards the uterus and forms 2, 4, 8, 16 daughter  cells. The embryo with 8 to 16 blastomeres is called morula.   - wherein     Cleavage divisions are mitiotic division, in which the single-celled zygote is converted into a multicellular morula. But during...
Medical
213 Views   |  

Vasa efferentia are the ductules leading from

  • Option 1)

    testicular lobules to rete testis

  • Option 2)

    rete testis to vas deferns

  • Option 3)

    vas deferns to the epididymis

  • Option 4)

    epididymis to urethra

 
As we discussed in concept male sex accessory ducts - The male sex accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens. - wherein The seminiferous tubules of the testis open into the vasa efferentia through rete testis. The vasa efferentia leave the testis and open into epididymis located along the posterior surface of each testis. The epididymis leads to vas...
Medical
119 Views   |  

Transfer of pollen grains from the anther to the stigma of another flower of same plant is called.

  • Option 1)

    Xenogamy

  • Option 2)

    Geitonogamy

  • Option 3)

    karyogamy

  • Option 4)

    Autogamy

 
As we discussed in concept Geitonogamy - Transfer of pollen grains from the anther to the stigma of another flower of the same plant. - wherein Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the same plant.       Option 1) Xenogamy This option is incorrect. Option 2) Geitonogamy This...
Medical
92 Views   |  

The signals for parturition originate from

  • Option 1)

    Placenta only

  • Option 2)

    Placenta as well as fully developed foetus

  • Option 3)

    oxytocin released from maternal pituitary

  • Option 4)

    fully developed foetus only

 
As we discussed in concept Foetal ejection reflex. - The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex. - wherein This triggers release of oxytocin from the maternal pituitary. Oxytocin acts on the uterine muscle and causes stronger uterine contractions, which in turn stimulates further...
Medical
177 Views   |  

The Second maturation division of the mammalian ovum occurs

  • Option 1)

    shortly after ovulation before the ovum makes entry into the fallopian tube

  • Option 2)

    until after the ovum has been penetrated by a sperm

  • Option 3)

    until the nucleus of the sperm has fused with that of the ovum

  • Option 4)

    in the graafian follicle following the first maturation division

 
As we discussed in concept Second Polar body - This induces the completion of the meiotic division of the secondary oocyte. The second meiotic division is also unequal and results in the formation of a second polar body and a haploid ovum (ootid) . -    The second maturation division of the mammalian ovum occurs until after the ovum has been penetrated by a sperm. Option 1) shortly after...
Medical
77 Views   |  

The part of fallopian tube closest to the ovary is

  • Option 1)

    isthmus

  • Option 2)

    infundibulum

  • Option 3)

    cervix

  • Option 4)

    ampulla

 
Correct Answer: infundibulum Explanation: The part of fallopian tube closest to the ovary is infundibulum. Infundibulum possess finger-like projections called fimbriae that help in collection of ovum after ovulation. It leads to wider part of oviduct called ampulla. The last part of oviduct is isthmus that has a narrow lumen and joins the uterus.
Medical
181 Views   |  

The first movements of the foetus and appearance of hair on its head are usually observed during which month of pregnancy.

  • Option 1)

    Fourth month

  • Option 2)

    Fifth month

  • Option 3)

    Sixth month

  • Option 4)

    Third month

 

Option 2 .i.e 5thh month acc. To new ncert 2019

Medical
94 Views   |  

Sertoli cells are found in

  • Option 1)

    ovaries and secrete progesterone

  • Option 2)

    adrenal cortex and secrete adrenaline 

  • Option 3)

    seminiferous tubules and provide nutrition to germ cells

  • Option 4)

    pancreas and secrete cholecystokinin

 
As we discussed in concept Structure of Testis - Each seminiferous tubule is lined on its inside by two types of cells called male germ cells (spermatogonia) and Sertoli cells - wherein       Option 1) ovaries and secrete progesterone This option is incorrect. Option 2) adrenal cortex and secrete adrenaline  This option is incorrect. Option 3) seminiferous tubules and provide nutrition to...
Medical
97 Views   |  

Seminal plasma in human males is rich in:

  • Option 1)

    fructose and calcium

  • Option 2)

    glucose and calcium

  • Option 3)

    DNA and testosterone

  • Option 4)

    ribose and potassium

 
As we discussed in concept Male accessory glands - The male accessory glands include paired seminal vesicles, a prostate and paired bulbourethral glands. - wherein Secretions of these glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes. The secretions of bulbourethral glands also helps in the lubrication of the penis.       Option 1) fructose and...
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