Daily Quiz: UPSC Prelims Marathon – November 16

The Union Cabinet has recently approved the creation of National Testing Agency (NTA) as an autonomous and self-sustained premier testing organization to conduct entrance examinations for higher educational institutions. It will be society registered under Indian Societies Registration Act, 1860.

The NTA will initially conduct entrance examinations currently being conducted by CBSE. Other examinations will be taken up gradually after NTA is fully geared up. These examinations will be conducted in online mode at least twice a year to give adequate opportunity to candidates to bring out their best. In order to serve requirements of the rural students, it will locate centres at sub-district and district level and as far as possible it will undertake hands-on training to the students.

Types of Immunity:

a) Innate immunity is present from the time of birth and provides protection against the entry of any foreign agent into our body. Skin and the mucous membranes prevent entry of foreign agents into the body. Hydrochloric acid in the stomach kills the germs that reach the stomach. White blood cells (WBC) engulf foreign particles and destroy them.

b) Acquired immunity- It develops during one’s life time by producing antibodies in response to foreign bodies termed antigens. Each antigen is recognised by a specific antibody. Antibodies’ are proteins produced by lymphocytes (a type of WBC), against specific antigen. Antibodies remember and recognize the infective agents that have once attacked the body and recognise and kill them when they enter the body again. This is called the memory of the immune system and is the basis of immunisation programme.

Chromosome The nucleus of every cell (except RBC of mammals) contains a fixed number of chromosomes. In all the cells of eukaryotes, chromosomes show the following typical characteristics:

1. They are present in pairs, one from the father and the other from the mother.
2. They can be seen only during cell division. In a non-dividing cell, they appear in the nucleus as a jumbled up network termed chromatin.
3. The paired chromosomes are present in a fixed number. A fixed set of chromosomes is termed the ‘diploid’ (paired) number and designated as 2n.
4. Each chromosome is made of one molecule of the chemical called DNA or deoxyribonucleic acid and some proteins.
5. Before cell division, the DNA molecule of a chromosome replicates (duplicates) to give two molecules of DNA which are called ‘chromatids.’ The two chromatids of a chromosome remain attached at a point called centromere and separate to form two chromosomes during cell division.

Note:  In the bacteria, only one chromosome (that is only one molecule of DNA) is present and since there is no well formed nucleus, the single chromosome lies in the cytoplasm in the region termed nucleoid.

All organisms are now classified into three major domains

1. Archaebacteria are thermophilic or heat loving bacteria that live in high temperature vents.
2. Eubacteria are single celled organisms without well developed nucleus.
3. Eukarya are all other organisms with a well formed nucleus in their cell/cells. (Eu: true; Karyon : nucleus)

Grey goo is a hypothetical end-of-the-world scenario involving molecular nanotechnology in which out-of-control self-replicating robots consume all biomass on Earth while building more of themselves, a scenario that has been called ecophagy (“eating the environment”, more literally “eating the habitation”). The original idea assumed machines were designed to have this capability, while popularizations have assumed that machines might somehow gain this capability by accident.

About ALMA:

High on the Chajnantor plateau in the Chilean Andes, the European Southern Observatory (ESO), together with its international partners, is operating the Atacama Large Millimeter/submillimeter Array (ALMA) — a state-of-the-art telescope to study light from some of the coldest objects in the Universe. This light has wavelengths of around a millimetre, between infrared light and radio waves, and is therefore known as millimetre and submillimetre radiation. ALMA comprises 66 high-precision antennas, spread over distances of up to 16 kilometres. This global collaboration is the largest ground-based astronomical project in existence.

What is submillimeter astronomy?

Light at these wavelengths comes from vast cold clouds in interstellar space, at temperatures only a few tens of degrees above absolute zero, and from some of the earliest and most distant galaxies in the Universe. Astronomers can use it to study the chemical and physical conditions in molecular clouds — the dense regions of gas and dust where new stars are being born. Often these regions of the Universe are dark and obscured in visible light, but they shine brightly in the millimetre and submillimetre part of the spectrum.

REPAIR is a  gene editing tool can tweak an individual RNA ‘letters’ in human cells without making changes to entire genome  and can have profound potential  as a tool for both research and disease treatment.REPAIR is based on gene editing tool CRISPR (Clustered Regularly Interspaced Short Palindrome Repeats) that can be used to modify DNA in cells. The new tool can change single RNA nucleosides in mammalian cells in a programmable and precise fashion