Zoology
- Receptors for sperm binding in mammals are present on : Answer: 4. Zona pellucida In mammals, sperm-binding receptors are present on the zona pellucida, the glycoprotein layer around the ovum. Bin... 1
- Which of the following secretes the hormone, relaxin, during the later phase of pregnancy ? Answer: 2. Corpus luteum Relaxin, which relaxes pelvic ligaments in late pregnancy, is secreted by the corpus luteum (and placenta). Graafia... 1
- Which of these is not an important component of initiation of parturition in humans ? Answer: 4. Release of Prolactin Parturition is initiated by foetal signals, rise in oestrogen to progesterone ratio, prostaglandin synthesis... 1
- Veneral diseases can spread through :(a) Using sterile needles(b) Transfusion of blood from infected person(c) Infected mother to foetus(d) Kissing(e) InheritanceChoose the correct answer from the options given below. Answer: 3. (b) and (c) only Sexually transmitted diseases spread by sexual contact, sharing of infected needles, blood transfusion from an i... 1
- Identify the types of cell junctions that help to stop the leakage of the substances across a tissue and facilitation of communication with neighbouring cells via rapid transfer of ions and molecules. Answer: 2. Tight junctions and Gap junctions, respectively. Tight junctions seal cells and stop leakage of substances across a tissue. Gap j... 1
- Now a days it is possible to detect the mutated gene causing cancer by allowing radioactive probe to hybridise its complimentary DNA in a clone of cells, followed by its detection using autoradiography because : Answer: 3. mutated gene does not appear on a photographic film as the probe has no complimentarity with it. The radioactive probe is a singl... 1
- Plasmid pBR322 has PstI restriction enzyme site within gene ampR that confers ampicillin resistance. If this enzyme is used for inserting a gene for β-galactoside production and the recombinant plasmid is inserted in an E.coli strain Answer: 1. it will not be able to confer ampicillin resistance to the host cell. The PstI site lies inside the ampR gene. Inserting the fore... 1
- A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is : Answer: 3. Palindromic Nucleotide sequences Restriction endonucleases recognise specific palindromic nucleotide sequences in DNA and cut at... 1
- Which one of the following organisms bears hollow and pneumatic long bones ? Answer: 1. Neophron Birds have light, hollow bones with air cavities (pneumatic bones) to help flight. Neophron (vulture) is a bird, so it h... 1
- Match List - I with List - II.List - I / List - II(a) Metamerism (i) Coelenterata(b) Canal system (ii) Ctenophora(c) Comb plates (iii) Annelida(d) Cnidoblasts (iv) PoriferaChoose the correct answer from the options given below. Answer: 3. (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i) Match each feature with its phylum. Metamerism (segmentation) - Annelida (iii) Canal syste... 1
- Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli. Answer: 1. High pO ₂ , low pCO ₂ , less H ^+ , lower temperature Oxygen binds haemoglobin best where pO ₂ is high and pCO ₂ is low. At the a... 1
- The partial pressures (in mm Hg) of oxygen (O_2) and carbon dioxide (CO_2) at alveoli (the site of diffusion) are : Answer: 1. pO ₂ = 104 and pCO ₂ = 40 Standard values in the alveoli are pO ₂ = 104 mm Hg and pCO ₂ = 40 mm Hg. pO ₂ 40 and pCO ₂ 45 are deox... 1
- Sphincter of oddi is present at : Answer: 2. Junction of hepato-pancreatic duct and duodenum The sphincter of Oddi guards the opening of the common hepato-pancreatic duct int... 1
- Which of the following statements wrongly represents the nature of smooth muscle ? Answer: 3. Communication among the cells is performed by intercalated discs Smooth muscles are unstriated, involuntary and found in walls of... 1
- Chronic auto immune disorder affecting neuro muscular junction leading to fatigue, weakening and paralysis of skeletal muscle is called as : Answer: 3. Myasthenia gravis An autoimmune attack on the neuromuscular junction causing fatigue and paralysis of skeletal muscle is myasthen... 1
- Which one of the following is an example of Hormone releasing IUD ? Answer: 2. LNG 20 Hormone releasing IUDs release progestogen or hormone slowly into the uterus. LNG-20 releases levonorgestrel. CuT, Cu7 and... 1
- Which of the following characteristics is incorrect with respect to cockroach ? Answer: 1. A ring of gastric caeca is present at the junction of midgut and hind gut. The incorrect statement is the one about gastric caeca... 1
- When gene targetting involving gene amplification is attempted in an individual’s tissue to treat disease, it is known as : Answer: 2. Gene therapy Treating a disease by correcting a defective gene, by delivering a normal gene into a person's cells and tissues, is... 1
- Which of the following is not an application of PCR (Polymerase Chain Reaction) ? Answer: 3. Purification of isolated protein PCR amplifies a chosen DNA segment from small amounts of DNA. It is used for gene amplification,... 1
- During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out : Answer: 2. DNA DNA is insoluble in ethanol. When chilled ethanol is added to the purified lysate, DNA precipitates and appears as fine threa... 1
- Which of the following is a correct sequence of steps in a PCR (Polymerase Chain Reaction) ? Answer: 1. Denaturation, Annealing, Extension Each PCR cycle has three steps in order: denaturation (double strand separated at about 94 °C)... 1
- The factor that leads to Founder effect in a population is : Answer: 4. Genetic drift The founder effect occurs when a small group of individuals starts a new population. Their allele frequencies diffe... 1
- The sequence that controls the copy number of the linked DNA in the vector, is termed : Answer: 2. Ori site The origin of replication (ori) is the sequence from where replication starts, and it controls the copy number of the li... 1
- Bilaterally symmetrical and acoelomate animals are exemplified by : Answer: 2. Platyhelminthes Platyhelminthes (flatworms) are bilaterally symmetrical and acoelomate. Ctenophora are radially symmetrical, Asch... 1