Hello Students Day 1 - Evening Coffee with NEET


1.Minerals Deficiency Diseases in Plants:
*Die back of Citrus - Copper
*Reclamation disease -Copper
*Yello tip of Oat-Copper
*Exanthema in Citrus-Copper
*Hooked leaf tip -Calcium
*Little leaf of grape veins- Zinc
*Mottle leaf of Citrus-Zinc
*Rosette of Apple-Zinc
*Khaira disease of Rice-Zinc
*Brown Heart rot of Turnip-Boron
*Internal Cork of Apple-Boron
*Whiptail of Cauliflower -Molybdenum
*Whiptail of Cabbage- Molybdenum
*Curled leaf margin-Potassium
*Yellow disease of Tea- Sulphur
*Chlorosis of Pine apple -Iron

2.Facts on Plant Hormones or Phytohormones:
*Gaseous plant hormone is Ethylene(a liquid called ETHEPHON is used to release Ethylene).
*Artificial ripening of fruits is done by Ethylene.
*Epinasty is caused by Ethylene.
* Stress hormone in plant(Stress phyto hormone) is Abscisic acid.
*Plant hormone promote abscission and senescence is ABA.
*Closing of the stomata is caused by a plant hormone Abscisic acid (ABA)
*Examples for Natural Auxin : Indole Acetic acid (IAA),Phenyl Acetic acid(PAA),Indole Butyric acid (IPA)
*Examples for Synthetic Auxin:2,4-Dichloro Phenoxy Acetic acid (2,4-D),Napthalene Acetic acid (NAA),2,4,5-Trichloro Phenoxy Acetic acid (2,4,5-5)
*Apical dominance is by Auxins
*Auxins used to eradicate weeds(weed killer).
*Avena seedlings curvature Test is a Bioassay for Auxin (or)IAA.
*Bolting (sudden elongation of stem followed by flowering) is caused by Gibberellins
*Bakanae disease or Foolish Seedling disease is caused by a fungus ,Gibberella fujikurai.(Studied in Japan by Eiichi Kurusowa in1926)
*Abscission is prevented by Auxin.
*Anti-gibberellin and Anti- auxin hormone is Abscisic acid.
*Substitute for low temperature for flowering is given  by Gibberellins.
*Gibberellin breaks dormancy in potato tubers.
*Auxins were isolated initially from human urine.
*GA3 is the first discovered gibberellin.
*Gibberellin was crystallized by Yabuta and Suniki in 1938.
*Gibberellin  initiates to produce male flowers in Cucurbits.
*Gibberellin called as gibberellic acid by Brain et al.
*Richmond Lang Effect (delaying the process of ageing in plants) is promoted by Cytokinin.
*Cytokinin  promotes cell division .
*Auxin (IAA) and Cytokinin (Kinetin) collectively initiates bud and root development in Callus(unorganised mass of undifferentiated tissue in tissue culture).
*Cytokinin found in Zea mays is called Zeatin.
*The plant hormone found in endosperm of coconut is Cytokinin.
*The hormone abundantly found in embryos ,developing fruits and roots is Cytokinin.
*Cytokinin was first isolated from Herring fish sperm DNA by Miller and Skoog.
*Chemical name of Kinetin is 6- Furfuryl Amino acid .
*Free auxin is IAA.
*Bound auxin is IAA-Aspartic acid .
*Precursor of IAA is amino acid Tryptophan .
*Zinc is essential for synthesis of Tryptophan.
*Anti- auxins are 2,4,5-Tri Iodine Benzoic Acid(TIBA) and Napthylpthalamine.
*The term auxin is first used by F.W.Went in 1926 and isolated auxin from Oats(Avena).
*The unilateral growth and curvature of Canary grass (Phalaris canariensis) coleoptile to light is observed in 1880 by Charles Darwin.
*Mixture of two Phenoxy herbicides 2,4-D and 2,4,5-T is given the name "AGENT ORANGE" which was used by USA in Vietnam War for defoliation of forest (Chemical warfare).

3.Important Vital Stains used in Cytological Techniques:
*EOSIN is used to stain Cytoplasm (Pink).
*FEULGEN'S STAIN is used to stain DNA(Purple).
*JANUS GREEN B is used to stain Mitochondria and Fungi(Green).
*METHYLENE BLUE is used to stain Golgi bodies and Yeast (Blue).
*TOLUDINE BLUE is used to stain RNA(Blue).
*HEMATOXYLINE is used to stain Nucleus and Cell Wall (Violet).

4.Absent (devoid of / lack of /not found )cases in plants :
*Phloem parenchyma, Phloem fibres Vascular cambium, Secondary growth and Shoot hairs( Trichomes) are absent in MONOCOTS.
*Xylem vessels or Trachae are absent in Gymnosperms EXCEPT Gnetum ,Ephedra and Welwitschia.
* Xylem fibres , Companion cells and Sieve tubes are absent in GYMNOSPERMS.
*Phloem fibres,Xylem fibres and Tracheids are absent in Dicot leaves.
* Vessels are absent in few angiopermic families Winteraceae,Tetracentraceae and Trochodendracae.

Mr.R.Soundarapandian, MSc, MEd, MPhil, 
PG Asst Zoology Sir 
MCTM Boys Higher Secondary School, 
Purasawalkam Chennai-84.

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