48 .With reference to the latest developments in stem cell research, consider the following statements. 1. The only source of human stem cells are the embryos at blastocyst stage. 2. The stem cells can be derived without causing destruction to blastocysts. 3. The stem cells can regenerate themselves in vitro virtually forever. 4. Indian research centres also created a few cell lines, which can be developed into many types. Which of these statements are right?
Renewable Energy.Data for 2013 shows that renewable electricity generation overtook natural gas to become the 2nd largest source of electricity worldwide producing 22% of total electricity or 5,130 TWh. Fossil fuels remained the bedrock of global electricity production with more than two-3rds (about 67%) of the total. Some of the sources of renewable energy are: solar power, wind power, wave & tidal power, geothermal power, biomass & hydro power.
folic acid.Anemia is a fall in number of red blood cells (RBCs) or less than the normal quantity of hemoglobin in the blood. As hemoglobin (found inside RBCs) normally carries oxygen from the lungs to the capillaries, anemia leads to hypoxia (lack of oxygen) in organs. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types and categories of hemoglobin deficiency. Megaloblastic anemia, the most common cause of macrocytic anemia, is due to a deficiency of either vitamin B12, folic acid, or both. Deficiency in folate and/or vitamin B12 can be due either to inadequate intake or insufficient absorption.
Neutron Star.The mass of a star which is two times the mass of the sun turns into a neutron star. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge & with slightly larger mass than protons. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Neutron stars are very hot & are supported against further collapse by quantum degeneracy pressure due to the Pauli's exclusion principle. This principle states that no two neutrons (or any other fermionic particles) can occupy the same place & quantum state simultaneously. A typical neutron star has a mass between about 1.4 & 3.2 solar masses (Chandrasekhar Limit), with a corresponding radius of about 12 km if the Akmalâ€“ Pandharipandeâ€“Ravenhall equation of state (APR EOS) is used.
Hepatic vein.The liver produces urea & other waste materials & then it pours it all in the right ventricle of the heart for oxygenation. So the impure blood brought by the Hepatic Vein & other blood vessels gets distributed through the aorta. The heart then distributes the blood to various parts of the body. This clearly signals that hepatic vein carries the largest amount of urea, while the renal vein carries the least.
Acetic acid.Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) & water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. Commercial vinegar is produced either by fast or slow fermentation processes. It is today mainly used in the kitchen as a general cooking ingredient, but historically, as the most easily available mild acid, it had a great variety of industrial, medical, & domestic uses, some of which (such as a general household cleanser) are still promoted today. Acetic acid has a distinctive sour taste & pungent smell. Besides its production as household vinegar, it is mainly produced as a precursor to polyvinylacetate & cellulose acetate. Although it is classified as a weak acid, concentrated acetic acid is corrosive, & attacks the skin.
is a disease spread by the bite of the female sandfly. This disease is the 2nd -largest parasitic killer in the world (after malaria). The parasite migrates to the internal organs such as liver, spleen (so 'visceral'), & bone marrow, and, if left untreated, will almost always result in the death of the host.
55 .Which among the given statements is/are right? 1. Viruses lack enzymes necessary for the generation of energy. 2. Viruses can be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only. Select the right answer using the codesgiven below
Femur.The femur or thigh bone, is the most proximal (closest to the center of the body) bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, & amphibians such as frogs. The femur is the largest bone in the human body. In vertebrates with four legs such as dogs & horses, the femur is found only in the rear legs. The head of the femur articulates with the acetabulum. By most measures the femur is one of the strongest bones in the body.
Lichen.Lichens can be used as air pollution indicators, especially of the concentration of sulfur dioxide in the atmosphere. This makes lichens natural indicators of air pollution. Air pollutants dissolved in rainwater, especially sulfur dioxide, can damage lichens, & prevent them from growing.
Ultra sound.Ultrasound is a technique that uses sound waves to show a picture of a baby (fetus) in the uterus. Echoes from the waves are analyzed by computer to produce a moving or still picture, called a sonogram, on a screen. It works by bouncing sound waves off the developing fetus. The technique is also called sonography.
D. Bacteria cannot survive in an active state in a solution of high osmotic strength as water is drawn out
Answer & Explanation
Answer : Option
Bacteria cannot survive in an active state in a solution of high osmotic strength as water is drawn out.The reason why bacteria doesnot grow in high concentration of sugar is as of sugar's high osmotic & dehydrating effects. This has the effect of drawing available water from within the food to the outside & inserting sugar molecules into the food interior. Sugar, whether in solid or aqueous form, attempts to reach equilibrium with the sugar content of the food product with which it is in contact. The result is a reduction of theso-called product water activity (aw), a measure of unbound, free water molecules in the food that is necessary for microbial survival & growth.Sugar's other antimicrobial mechanisms include interference with a microbe's enzyme activity & weakening the molecular structure of its DNA (Scientific American Journal).