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Medical
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Which one of the following shows isogamy  with non-flagellated gametes?

  • Option 1)

    Sargassum 

  • Option 2)

    Ectocarpus 

  • Option 3)

    Ulothrix 

  • Option 4)

    Spirogyra 

 
  Reproduction in chlorophyceae - Vegetative by fragmentation or fission. Asexual by Zoospores. Sexual by Isogamous to oogamous. -   Spirogyra belongs to class chlorophyceae which shows isogamy with non flagellated gametes Option 1) Sargassum  This is incorrect option Option 2) Ectocarpus  This is incorrect option Option 3) Ulothrix  This is incorrect option Option 4) Spirogyra  This is...
Medical
91 Views   |  

Viruses have:

  • Option 1)

    DNA enclosed in a protein coat

  • Option 2)

    Prokaryotic nucleus 

  • Option 3)

    Single chromosome 

  • Option 4)

    Both DNA and RNA 

 
As discussed 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. -     Viruses have DNA enclosed in a protein coat. Option 1) DNA enclosed in a protein coat This option is correct. Option 2) Prokaryotic nucleus  This option is incorrect. Option 3) Single...
Medical
166 Views   |  

Which of the following shows coiled RNA strand and capsomeres?

  • Option 1)

    Polio virus 

  • Option 2)

    Tobacco mosaic virus 

  • Option 3)

    Measles virus 

  • Option 4)

    Retrovirus 

 
As we learnt in Tobacco mosaic virus (TMV) - RNA is ssRNA - wherein Infects members of family solanaceae.    and,   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. -   Tobacco mosaic virus shows coiled RNA strand and capsomeres.   Option 1) Polio...
Medical
199 Views   |  

The motile bacteria are able to move by:

  • Option 1)

    Fimbriae

  • Option 2)

    Flagella 

  • Option 3)

    Cilia 

  • Option 4)

    Pili

 
As learnt in Flagellum - Organ of motality in bacteria. Arise from basal granule called blepharoplast. - wherein Made up of basal body, hook and filament.       The motile bacteria are able to move by Flagella. Option 1) Fimbriae This option is incorrect. Option 2) Flagella  This option is correct. Option 3) Cilia  This option is incorrect. Option 4) Pili This option is incorrect.
Medical
82 Views   |  

Archaebacteria differ from eubacteria in:

  • Option 1)

    Cell membrane

  • Option 2)

    Mode of nutrition 

  • Option 3)

    Cell shape 

  • Option 4)

    Mode of reproduction 

 
As learnt in Archaebacteria - Live in harsh habitats. Cell walls lack muramic acid and peptidoglycan. Branched lipids having Phytanyl side groups decreases membrane fluidity. - wherein They are of three major type Methanogens Halophiles Thermoacidophiles     and,     Eubacteria - Cosmopolitan in distribution Rigid cell wall is present. - wherein They are of two type. Bacteria Cyano...
Medical
100 Views   |  

Five kingdom system of classification suggested by R.H. Whittaker is not based on:

  • Option 1)

    Presence or absence of a well defined nucleus 

  • Option 2)

    Mode of reproduction 

  • Option 3)

    Mode of nutrition 

  • Option 4)

    Complexity of body organisation 

 
As discussed in Five kingdom Classification - Proposed by Whittaker (1969). The main criteria for classification include cell structure, body organisation, mode of nutrition, reproduction phylogenetic relationship. - wherein Five kingdoms includes : Monera Protista Fungi Plantae Animalia.     Five kingdom system of classification suggested by R.H. Whittaker is not based on presence or...
Medical
136 Views   |  

Commonly used vectors for a human genome sequencing are:

  • Option 1)

    T-DNA

  • Option 2)

    BAC and YAC

  • Option 3)

    Expression Vectors

  • Option 4)

    kT/A Cloning Vectors

 
As learnt in Size of insert in other vectors - Bactripohage-can take up to N 25 Kbps.  Cosmid-constructed vector contains cos site from  phage DNA with plasmid and can take up to 45-48 kb insert.  Plasmid-Contains phase DNA and plasmid DNA and can take up to 100 kb.  BAC-can take up to 250-300kb  insert  YAC-can take up to 500 Kbs insert  MAC-can take up to 1 Mbp insert  -    and Human genome...
Medical
148 Views   |  

Which vector can clone only a small fragment of DNA ?

  • Option 1)

    Bacterial artificial chromosome

  • Option 2)

    Yeast artificial chromosome

  • Option 3)

    Plasmid

  • Option 4)

    Cosmid

 
As learnt in Plasmids - A plasmid is a small, circular double standard DNA molecules; has power of self replication. They usually exist in bacteria and some lower eukaryotes. They have antibiotic resistance gene. - wherein Plasmids provide genetic advantages like antibiotic resistance.     Option 1) Bacterial artificial chromosome This option is incorrect Option...
Medical
106 Views   |  

An analysis of chromosomal DNA using Southern hybridization technique does not use:

  • Option 1)

    Electrophoresis

  • Option 2)

    Blotting

  • Option 3)

    Autoradiography

  • Option 4)

    PCR

 
As we learnt in 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 is used for DNA only.    and Gel Electrophoresis - This technique is used to separate DNA fragments on the basis of charge and size. Agarose is a polysaccharide...
Medical
119 Views   |  

Which one of the following statements is not correct?

  • Option 1)

    Retinal is the light absorbing portion of visual photo pigments.

  • Option 2)

    In retina the rods have the photopigment rhodpsin while cones have three different photopigments.

  • Option 3)

    Retinal is a derivative of vitamin C.

  • Option 4)

    Rhodopsin is the purplish red protein present in rods only.

 
  Visual cortex - the photosensitive compounds (photopigments) in the human eyes is composed of opsin (a protein) and retinal (an aldehyde of vitamin A). Light induces dissociation of the retinal from opsin resulting in changes in the structure of the opsin. This causes membrane permeability changes. - wherein As a result, potential differences are generated in the photoreceptor cells. This...
Medical
88 Views   |  

Which of the following causes an increase in sodium reabsorption in the distal convoluted tubule?

  • Option 1)

    Increase in aldosterone levels

  • Option 2)

    Increase in antidiuretic hormone levels

  • Option 3)

    Decrease in aldosterone levels

  • Option 4)

    Decrease in antidiuretic hormone levels

 
  Aldosterone - Aldosterone acts mainly at the renal tubules and stimulates the reabsorption of Na+ and water and excretion of K+ and phosphate ions. - wherein Thus, aldosterone helps in the maintenance of electrolytes, body fluid volume, osmotic pressure and blood pressure. Small amounts of androgenic steroids are also secreted by the adrenal cortex which play a role in the growth of axial...
Medical
103 Views   |  

The intial step in the digestion of milk in humans is carried out by?

  • Option 1)

    Lipase

  • Option 2)

    Trypsin

  • Option 3)

    Rennin

  • Option 4)

    Pepsin

 
As learnt Rennin - Rennin is a proteolytic enzyme found in gastric juice of infants - wherein It helps in the digestion of milk proteins. Small amounts of lipases are also secreted by gastric glands.    Rennin helps in digestion of milk protein. Option 1) Lipase This option is incorrect Option 2) Trypsin This option is incorrect Option 3) Rennin This option is correct Option 4) Pepsin This...
Medical
126 Views   |  

Stimulation of a muscle fiber by a motor neuron occurs at:

  • Option 1)

    the neuromuscular junction

  • Option 2)

    the transverse tubules

  • Option 3)

    the myofibril

  • Option 4)

    the sacroplasmic reticulum

 
  Mechanism of Muscle Contraction - neuromuscular junction. - wherein The junction between a motor neuron and the sarcolemma of the muscle fibre is called the neuromuscular junction or motor-end plate.     Option 1) the neuromuscular junction Correct Option 2) the transverse tubules Incorrect Option 3) the myofibril Incorrect Option 4) the sacroplasmic reticulum Incorrect
Medical
93 Views   |  

Person with blood group AB is considered as universal recipient because he has:

  • Option 1)

    both A and B antigens on RBC but no antibodies in the plasma.

  • Option 2)

    both A and B antibodies in the plasma.

  • Option 3)

    no antigen on RBC and no antibody in the plasma.

  • Option 4)

    both A and B antigens in the plasma but no antibodies.

 
  Universal Recipients - Persons with ‘AB’ group can accept blood from persons with AB as well as the other groups of blood. - wherein Therefore, such persons are called ‘universal recipients’    AB is universal acceptor Option 1) both A and B antigens on RBC but no antibodies in the plasma. This solution is correct  Option 2) both A and B antibodies in the plasma. This solution is...
Medical
252 Views   |  

Injury localized to the hypothalamus would most likely disrupt:

  • Option 1)

    short - term memory.

  • Option 2)

    co- ordination during locomotion.

  • Option 3)

    executive function, such as decision making.

  • Option 4)

    regulation of body temperature.

 
  Hypothalamus - Another very important part of the brain called hypothalamus lies at the base of the thalamus. - wherein The hypothalamus contains a number of centres which control body temperature, urge for eating and drinking. It also contains several groups of neurosecretory cells, which secrete hormones called hypothalamic hormones.     Option 1) short - term memory. This solution is...
Medical
77 Views   |  

Identify the hormone with its correct matching of source and function:

  • Option 1)

    Oxytocin - posterior pituatory, growth and maintenance of mammary glands.

  • Option 2)

    Melatonin - pineal gland, regulates the normal rhythm of sleepwake cycle.

  • Option 3)

    Progesterone - corpus - luteum, stimulation of growth and activities of female secondary sex organs.

  • Option 4)

    Atrial natriuretic factor - ventricular wall increases the blood pressure.

 
As learnt in Melatonin - Melatonin plays a very important role in the regulation of a 24-hour (diurnal) rhythm of our body - wherein For example, it helps in maintaining the normal rhythms of sleep-wake cycle, body temperature. In addition, melatonin also influences metabolism, pigmentation, the menstrual cycle as well as our defense capability    Melatonin maintains the biological clock or...
Medical
114 Views   |  

How do parasympathetic neural signals affect the working of the heart?

  • Option 1)

    Reduce both heart rate and cardiac output.

  • Option 2)

    Heart rate is increased without affecting the cardiac output.

  • Option 3)

    Both heart rate and cardiac output increase

  • Option 4)

    Heart rate decreases but cardiac output increases.

 
As learnt in Factors affecting Cardiac Output - Parasympathetic neural signals (another component of ANS) decrease the rate of heart beat, speed of conduction of action potential and thereby the cardiac output. -     Option 1) Reduce both heart rate and cardiac output. This option is correct Option 2) Heart rate is increased without affecting the cardiac output. This option is incorrect Option...
Medical
120 Views   |  

Fight - or - flight reactions cause activation of:

  • Option 1)

    the parathyroid glands, leading to increased metabolic rate.

  • Option 2)

    the kidney, leading to suppression of reninangiotensin - aldeosterone pathway.

  • Option 3)

    the adrenal medulla, leading to increased secretion of epinephrine and norepinephrene.

  • Option 4)

    the pancreas leading to a reduction in the blood sugar levels.

 
As learnt in Adrenaline and noradrenaline - Adrenaline and noradrenaline are rapidly secreted in response to stress of any kind and during emergency situations and are called emergency hormones or hormones of Fight or Flight - wherein These hormones increase alertness, pupilary dilation, piloerection (raising of hairs), sweating etc. Both the hormones increase the heart beat, the strength of...
Medical
262 Views   |  

Choose the correctly matched pair:

  • Option 1)

    Inner lining of salivary ducts - Ciliated epithelium

  • Option 2)

    Moist surface of buccal cavity - Glandular epithelium

  • Option 3)

    Tubular parts of nephrons - Cuboidal epithelium

  • Option 4)

    Inner surface of bronchioles - squamous epithelium

 
As we discussed in concept FUNCTION OF THE TUBULES - Proximal Convoluted Tubule (PCT) - wherein PCT is lined by simple cuboidal brush border epithelium which increases the surface area for reabsorption. Nearly all of the essential nutrients, and 70-80 per cent of electrolytes and water are reabsorbed by this segment    Cuboidal epithelium is present in tubular part of nephrons. Option...
Medical
94 Views   |  

Approximately seventy percent of carbon - dioxide absorbed by the blood will be transported to the lungs :

  • Option 1)

    as bicarbonate ions

  • Option 2)

    in the form of dissolved gas molecules

  • Option 3)

    by binding to R.B.C

  • Option 4)

    as carbamino - haemoglobin

 
As we discussed in concepts Oxyhaemoglobin - O2 can bind with haemoglobin in a reversible manner to form oxyhaemoglobin. - wherein Each haemoglobin molecule can carry a maximum of four molecules of O2. Binding of oxygen with haemoglobin is primarily related to partial pressure of O2.    and Carboxyhaemoglobin - Carboxyhaemoglobin (symbol COHb or HbCO) is a stable complex of carbon monoxide and...
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