Test: Biology - 3 - UPSC MCQ

Jaundice is a result of increased bile pigments in the blood. Defects of heart valves leads to stenosis, in which the blood vessels are narrowed abnormally so, there is abnormal blood sounds. Highly allergic infection and inflammation of nose is known as Rhinitis. Paralysis is the loss of motor functions due to damage to nervous system.

Antibiotics act against the growth of microorganisms. Some antibiotics are broad range and others are specific being active against many microorganismal species or selective for only some. The ‘Resistance genes’ in the bacteria develop resistance against a particular antibiotic over a long time due to mutation and thus, that particular antibiotic does not act on this resistant mutant strains.

Temperate climatic zones see spring and autumn distinctly in a year. Spring brings plenty of water that the trees can take up to form larger xylem vessels and a broader and soft 'spring wood'. In late summer or in winters, the climate becomes dry severing enough water supply, thus, the vascular cambium cuts off smaller xylem vessels forming a narrow and darker dense 'autumn woods'. Spring and autumn woods together form a growth ring or annual growth ring. Counting each growth ring as the age of the tree.

Carolus Linnaeus is credited as the father of modern taxonomy. He had created the binomial nomenclature of the living organism as he introduced it in Species Plantarum in 1753. The term taxonomy was originally coined by Augustin Pyramus de Candolle in 1813.

Ribosomes are the sites of protein synthesis in the cytoplasm of the cells. The RNA template sits in between the two subunits of the ribosomes and the peptide synthesis take place. Intracellular digestion occurs via lysosomes. The mitochondria are the sites of cellular respiration and power house of the cells generating ATPs. The nucleus contains all the genetic materials which get expressed to produce a phenotype thus, making nucleus the controller of the cells.

Somatic cells undergo mitosis during the cell cycle. The phase in which the cells undergo division is called M-phase. The first stage of this phase is prophase, the second is metaphase in which the chromosomes come and lie at the equatorial plate. This stage is followed by anaphase in which the sister chromatids separate out and go to the poles. The telophase is the last stage when the cell’s cytoplasm is divided to give rise to two daughter cells.

The cell was discovered by Robert Hooke in 1665. The nucleus was the first organelle to be discovered. The oldest description of the nucleus was given by Anton van Leeuwenhoek (1632– 1723). But the nucleus was described in more detail for the first time in 1831 by Scottish botanist Robert Brown in a talk at the Linnean Society of London. Lysosomes are found in animal cells but their presence in yeasts and plant cells is disputed.

NBRI — Lucknow, CPRI — Shimla, CRRI — Cuttack, CFRI — Dehradun

Sundews are one of the largest genera of carnivorous plants. These are the members of the family Droseraceae. So, Drosera is a sundew carnivorous plant. Dionaea is the member of the family Tachinidae, commonly called as venus flytrap. Utricularia is member of the family Lentibulariaceae, which are carnivorous, plants commonly known as bladderworts. Nepenthes are genera comprising tropical carnivorous plants and also known as monkey cups. These are generally found in old world tropics.

The dark reactions of photosynthesis occur in the stroma of the chloroplast. The light reactions occur in the thylakoid membranes or the grana of the chloroplasts. The glycolytic pathways occur in the cytoplasm of the cells. Kreb's cycle or tricarboxylic acid or citric acid cycle occurs in the mitochondria to produce energy through oxidation.

Living fossils are those organisms whose close relatives are not living on the earth. Cycas is a living fossil. Zamia pygmaea is endemic to Cuba and is the smallest gymnosperm on the earth. Sequoiadendron giganteum is the tallest coniferous gymnosperm known as redwoods. Canada balsam is obtained from the Abies balsamea (a North American fir) also known as Canada balsam.

Sphagnum is also called as peat moss. These have leaf-like appendages that have many circular openings which enable them to absorb liquids readily. Thus they are commercially important as soil structure enhancer, packing material for living plants. Ephedrine is a sympathomimetic amine commonly used as a stimulant, appetite suppressant, concentration aid, decongestant. Ephedrine is obtained from the plant Ephedra sinica and other members of the Ephedra genus.

Selaginella bryopteris, a lithophytic plant, is used as a medicinal plant in India and commonly known as 'Sanjeevani' or one that infuses life. It is very much drought hardy and can remain alive for many years without water. Adiantum is the maiden hair fern. Equisetum or horsetail is a living fossil and the only living genus of class Equisetopsida. Dryopteris is commonly known as wood fern or male fern.

Bryophytes are the phylum of small simple plants with no vascular tissue and root like rhizoids. They are called the amphibians of the plant kingdom as they can survive in both conditions with and without water. Selaginella is an example of Pteridophyte.

In the leaves, the photosynthates or sugars are converted into starch and via phloem their transport to all the other parts occur. The xylem cells transport only water and some minerals from the roots upto the shoots. The xylem vessels are dead cells with empty lumen but they are hard to carryout the water transport by depositing secondary wall materials, such as lignin.

Lichens are the symbiotic association of algae and fungi. The algal member is generally a green alga or blue-green alga. The fungal partner is usually of Ascomycota. Lichens are sensitive to pH change, thus making them good indicators of pollution or SO2 as the later makes H2SO4 with water.

In sewage treatment tanks, different aerobic bacteria are used to degrade organic wastes. 'Chlorella' is used as a source of providing oxygen to the bacteria. Chlorella is an attractive food source as it is high in protein and other essential nutrients. Dried Chlorella contains around 45% protein, 20% fat, 20% carbohydrate and pretty good amount of vitamins. Chlorella is a potential plant to be used in space flight shuttles for continuous oxygen supply. Chlorellin is an antibiotic obtained from chlorella.

Three types of cells are found in pancreas. ∝-cells, β-cells, δ-cells. ∝-cells secrete peptide hormone glucagon.  β-cells synthesise and secrete the endocrine hormone, insulin, the hyposecretion of which leads to abnormal metabolism of body’s sugar and causes Diabetes mellitus. δ-cells produce somatostatin.

Lymphatic filariasis is caused by nematodes of genera, Wuchereria bancrofti, Brugia malayi and Brugia timori, which occupy the lymphatic system, including the lymph nodes. In chronic cases, the worms lead to disease elephantiasis in which legs and sometimes genital organs swell up.

Progeria or Hutchinson-Gilford progeria syndrome is a genetic disease with a defect in the gene LMNA, in which the ageing process is manifested at a very early age and the progeric children typically live to their mid-teens to early twenty.