33 public questions tagged with this topic.
Infectious mononucleosis, also known as the "kissing disease, " is caused by the Epstein-Barr virus (EBV). This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Human Health and Disease, Topic: Immunity, diseases and health maintenance.
Plateau phase, also termed stationary phase, occurs when culture reaches carrying capacity constrained by surface area for adherent cells or nutrient limits for suspension cells. Cell number stabilizes as division rate equals death rate, curve flattening. Molecular mechanisms include contact inhibition mediated by Hippo pathway: high cell density activates LATS1/2 kinases phosphorylating YAP leading to cytoplasmic retention and degradation preventing transcription of cyclin D1 and survivin. Cadherin engagement also induces p27Kip1. Simultaneously growth factor exhaustion, accumulation of inhib
Ref: Alberts MBoC Ch.17 Plateau contact inhibition Hippo YAP; Freshney Ch.13 Growth curve plateau stationary quiescence balance.
MDCK cells are premier model for epithelial physiology because they form highly polarized monolayers with distinct apical membrane enriched in glycoproteins with GPI anchors and basolateral membrane containing receptors for growth factors, enabling study of protein sorting signals such as tyrosine motifs and raft-dependent trafficking via Par3-Par6-aPKC polarity complex. They develop tight junctions that restrict paracellular diffusion, allowing measurement of drug permeability, P-glycoprotein mediated efflux, and toxicant effects on barrier integrity. In influenza research, MDCK is gold stand
Ref: Simons K & Fuller SD Annu Rev Cell Biol 1985 MDCK polarity; WHO Manual Influenza diagnostics: MDCK culture influenza virus study.
Vero cells are particularly valuable for vaccine production and virology because deletion of interferon alpha/beta genes prevents establishment of antiviral state normally triggered by viral RNA sensing via RIG-I and MDA5 activating IRF3. Consequently viruses replicate to high titers enabling efficient bulk production under Good Manufacturing Practice. Poliovirus inactivated polio vaccine, rabies vaccine, Japanese encephalitis vaccine, and rotavirus vaccine are produced in Vero microcarrier cultures. Regulatory agencies accept Vero because extensive documentation demonstrates absence of tumori
Ref: WHO Requirements for Vero cells for vaccine production TRS 978 Annex 3; Barrett et al Biologicals 2009 Vero interferon deficiency vaccine.
Vero cell line originates from kidney epithelial tissue excised from adult African green monkey Chlorocebus aethiops, formerly Cercopithecus aethiops, at Chiba University Japan in 1962 by Yasumura and Kawakita. Designation Vero derived from Esperanto phrase Verda Reno meaning green kidney. Cells exhibit epithelial-like cobblestone morphology, anchorage dependence, contact inhibition, and were initially diploid but later became aneuploid after continuous passage. Critical molecular feature is homozygous deletion of approximately 9 megabase region on chromosome 12 encoding type I interferon gene
Ref: Yasumura Y & Kawakita Y Nippon Rinsho 1963 Vero African green monkey kidney; Desmyter et al J Virol 1968 Interferon deficiency in Vero.
AIDS is caused by the Human Immunodeficiency Virus (HIV), which attacks the immune system.
Ref: NCERT Class 12 Biology Chapter 7: Human Health and Disease Immune Disorders - Allergies Autoimmunity and AIDS
The common cold is caused by rhinoviruses, which infect the upper respiratory tract.
Ref: NCERT Class 12 Biology Chapter 7: Human Health and Disease Common Diseases - Viral - Common Cold and Other Viral Diseases
T-cytotoxic cells (CD8+ cells) destroy virus-infected cells by inducing apoptosis.
Ref: NCERT Class 12 Biology Chapter 7: Human Health and Disease Common Diseases - Viral - Common Cold and Other Viral Diseases
M. W. Beijerinck showed that extract from infected tobacco plants could infect healthy plants. He called the infectious fluid âContagium vivum fluidum,â meaning infectious living fluid.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Five Kingdom Classification and Kingdom Plantae Animalia
Viroids are infectious agents made of low-molecular-weight RNA. They lack the protein coat found in viruses and were discovered by T. O. Diener.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Viruses Viroids Prions and Lichens
The particle is a virus. Viruses remain inert outside their specific host cells but take over the host-cell machinery after infection to produce additional virus particles.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Viruses Viroids Prions and Lichens
The agent is a viroid. T. O. Diener discovered viroids while studying potato spindle tuber disease. Viroids consist of free RNA of low molecular weight and lack the protein coat found in viruses.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Viruses Viroids Prions and Lichens
