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Part 109 – Biology Previous Year Questions

Q1. Smut of wheat is coused by
(a) Ustilago maydis
(b) Puccinia graminis
(c) Ustilago tritici
(d) Colletotrichum falcatum
Ans: (c) Smut of wheat is caused by Ustilago tritici.

Q2. Which base in place of thymine is present in RNA ?

(a) Adenine (b) Guanine
(c) Uracil (d) Cytosine
Ans: (c) DNA (Deoxyribonucleic acid) contains 2-deoxyribose sugar. It contains cytosine and thymine as pyrimidine bases and guanine and adenine as purine bases. RNA (Ribonucleic acid) contains ribose sugar. It contains cytosine and uracil as pyrimidine bases and guanine and adenine as purine bases.

Q3. Protein part of enzyme is know as

(a) Isoenzyme
(b) Holoenzyme
(c) Apoenzyme
(d) All the above
Ans: (c) Enzymes are defined as biological catalysts. Chemically all enzymes are globular proteins. Each enzyme catalyses only one chemical reaction. Protein part of enzyme is known as Apoenzyme.

Q4. Time required for the organism to eliminate 50% the total body burden or tissue concentration of chemical is referred as

(a) Threshold limit time
(b) Half-time life
(c) Residual period
(d) Half-life period
Ans: (d) Time required for the organism to eliminate 50 per cent of the total body burden or tissue concentration of chemical is referred to as Half Life Period.

Q5. The ambient air quaility standard
(24 hours’ average) for lead in industrial area is

(a) 0.65 μg/m3
(b) 0.75 μg/m3
(c) 1.0 μg/m3
(d) 1.5 μg/m3
Ans: (d) The ambient air quality standard (24 hours’ average) for lead in industrial area is 1.5 μg/m3

Q6. Thinner particles responsible for deteriorating the air-quality resulting in the damage of vital body organs are referred as PM:

(a) 15.5 (b) 10.5
(c) 2.5 (d) 20.5
Ans: (c) The term fine particles, or particulate matter 2.5 (PM2.5), refers to tiny particles or droplets in the air that are two and one half microns or less in width. Particles in the PM2.5 size range are able to travel deeply into the respiratory tract, reaching the lungs. Exposure to fine particles can cause short-term health effects such as eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath. Exposure to fine particles can also affect lung function and worsen medical conditions such as asthma and heart disease.

Q7. An example of protein which acts as a hormone is :

(a) Trypsin (b) Oxytocin
(c) Keratin (d) Casein
Ans: (b) Hormonal Proteins are messenger proteins which help to coordinate certain bodily activities. Examples include Insulin, Oxytocin, and Somatotropin. Oxytocin stimulates contractions in females during childbirth.

Q8. The primary producer in an ecosystem are;

(a) Women (b) Men
(c) Plants (d) Bacteria
Ans: (c) Primary producers are the organisms in an ecosystem that produce biomass from inorganic compounds (autotrophs). In almost all cases these are photosynthetically active organisms (plants, cyanobacteria and a number of other unicellular organisms.

Q9. Some of the ingredients required for bread making are:

(a) Maida and Yeast
(b) Maida and Baking Powder
(c) Maida and Baking Soda
(d) Maida and Ghee
Ans: (a) Salt, fat and leavening agents such as yeast and baking soda are common ingredients, though bread may contain other ingredients also. Yeast plays an important role in bread-making. It ferments and grows when combined with “food” such as flour and/ or sugar, and warmed. Carbon dioxide is produced and trapped in the dough as tiny air bubbles which make the bread rise during cooking and give it its characteristic texture.

Q10. Which one of the following hormone is called ”Emergency Hormone” ?

(a) Adrenaline (b) Thyroxine
(c) Vasopressin (d) Insulin
Ans: (a) Adrenalin is often referred to as ‘emergency hormones’ because they are released when a person feels excited. Thus, it is this hormone that often gives people the strength to do otherwise-impossible deeds and prevent emergencies.

Q11. Malaria is transmitted from one person to another by:

(a) Aedes Mosquito
(b) Culex Mosquito
(c) Anopheles Mosquito
(d) All of the above
Ans: (c) Malaria is a mosquito-borne infectious disease which begins with a bite from an infected female Anopheles mosquito, which introduces the protists through saliva into the circulatory system. In the blood, the protists travel to the liver to mature and reproduce.

Q12. Liver is a RICH source of :

(a) sugars
(b) fat soluble vitamins
(c) minerals
(d) proteins
Ans: (d) In general, liver is a good source of vitamin A, iron, zinc, copper and manganese, and a very good source of protein. There are twenty grams of protein in a single slice of liver.

Q13. Cuscuta is a :

(a) Saprophyte (b) Epiphyte
(c) Xerophyte (d) Parasite
Ans: (d) Cuscuta (dodder) is a genus of about 100–170 species of yellow, orange, or red parasitic plants. Dodder is parasitic on a very wide variety of plants, including a number of agricultural and horticultural crop species, such as alfalfa, lespedeza, flax, clover, potatoes, etc.

Q14. The number of eggs normally released during one menstrual cycle is:

(a) 3 (b) 2
(c) 1 (d) 4
Ans: (c) In each menstrual cycle, rising levels of oestrogen cause the ovary to develop an egg and release it (ovulation). After ovulation, the egg lives for 24 hours.

Q15. The animal that do not develop hypertension inspite of heavy intake of salt is:

(a) Sheep (b) Buffalo
(c) Tiger (d) Camel
Ans: (d) The daily salt intake of camels is eight times that of a typical cow or sheep. Yet, surprisingly, they do not develop high blood pressure. Similarly, their blood sugar levels are twice those of other cudchewing animals; still they do not develop diabetes.

Q16. The pol lutants which move downward with percolating ground water are called

(a) Leachates (b) Pollutates
(c) Earthites (d) Percolates
Ans: (a) Leachate is any liquid that, in passing through matter, extracts solutes, suspended solids or any other component of the material through which it has passed. In older landfills and those with no membrane between the waste and the underlying geology, leachate is free to egress the waste directly into the groundwater. In such cases high concentrations of leachate are often found in nearby springs and flushes.

Q17. Lungs are located in the

(a) abdominal cavity
(b) pericardial cavity
(c) peritoneal cavity
(d) pleural cavity
Ans: (d) In human anatomy, the pleural cavity is the potential space between the two pleura (visceral and parietal) of the lungs. The pleura is a serous membrane which folds back onto itself to form a twolayered membrane structure.

Q18. Which one of the following is the ideal food for newborn babies ?

(a) Water (b) Sugar
(c) Honey (d) Milk
Ans: (d) The best food for the newborn baby is mother’s milk. Breast milk is free from contamination and adulteration and supplies nutrients in almost correct amounts.

Q19. Transcription means the synthesis of

(a) Lipids (b) Protein
(c) DNA (d) RNA
Ans: (c) Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme, RNA polymerase. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand.

Q20. Hydrochloric acid is secreted by the cells lining the

(a) Oral cavity (b) Stomach
(c) Ileum (d) Colon
Ans: (b) The chief cells of the stomach secrete enzymes for protein breakdown (inactive pepsinogen and rennin). Hydrochloric acid activates pepsinogen into the enzyme pepsin, which then helps digestion by breaking the bonds linking amino acids, a process known as proteolysis.

Q21. Emulsification is

(a) breaking fats into small globules
(b) digestion of fats
(c) absorption of fats
(d) storage of fats
Ans: (a) Emulsification is the breakdown of large fat globules into smaller, uniformly distributed particles. It is accomplished mainly by bile acids in the small intestine. Emulsification is the first preparation of fat for chemical digestion by specific enzymes.

Q22. Taxonomy is a science that deals with

(a) Morphology
(b) Anatomy
(c) Classification
(d) Economic uses
Ans: (c) Taxonomy is the academic discipline of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. Each group is given a rank and groups of a given rank can be aggregated to form a super group of higher rank and thus create a hierarchical classification.

Q23. The outer skin most of the crustaceans are made up of a carbohydrate. This carbohydrate is

(a) cellulose (b) galactose
(c) chitin (d) starch
Ans: (c) All crustaceans have a body covered with a protective shell composed of a horny substance called chiton. The outer skeleton is not continuous but made up of divided sections called somites.

Q24. Blood pressure may be increased by the excessive secretion of

(a) Thyroxine
(b) Testosterone
(c) Estradiol
(d) Estrol
Ans: (a) With its excess secretion, also known as hypersecretion, thyroxin (T4) causes an increased heart rate, high blood pressure, possible palpitations, and could lead to heart failure. It is related to hyperthyroidism.

Q25. The Particulate Matter (PM-10) exhaled from the pol luted atmosphere is often filtered out during the process of

(a) Coughing (b) Sneezing
(c) A and B (d) Urination
Ans: (b) PM-10 is a particulate matter having an aerodynamic diameter of less than 10 μm. Particles larger than 10 microns tend to be filtered out in the nose and therefore do not enter the respiratory tract.

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