NEET Biology Solved Question Paper 2014

Micronutrients are elements needed in small amounts (less than 10 mmole$/$kg of dry matter). These are 8 in number and include iron, manganese, copper, molybdenum, zinc, boron, chlorine and nickel.

In pteridophytes, majority of plants are homosporous (producing similar kind of spores) e.g., Lycopodium. However, plants of genera like Selaginella and Salvinia are heterosporous (producing macro and micro spores). Pinus and Cycas, which are gymnosperms, are also heterosporous.

The cells derived from root apical and shoot apical meristems and cambium differentiate and mature to perform special functions. This act leading to maturation is termed as differentiation.

Differentiation is the process by which a less specialized cell becomes a more specialized cell type. It is part of developmental biology. Different tissues have different kinds of organisms inside the cells. Differentiation occurs many times during the development of a multicellular organism.

DNA and RNA are nucleic acids which are found in living systems. DNA is a long polymer of deoxyribonucleotides and RNA is a long polymer of ribonucleotides. A nucleotide has 3 components- a nitrogenous base, a pentose sugar and a phosphate group.

Coconut and cucurbits are monoecious plants. Ornithorhynchus is an egg-laying mammal. Whale is a viviparous mammal. Frog shows external fertilisation. It takes place in water. Peacock shows internal fertilisation

Vernalization is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower.

Many temperate plants have vernalisation requirement and must experience a period of low temperature in winter, to initiate or accelerate flowering process, or in many fruit tree species, to induce dormancy and then break dormancy prior to flowering.

Cell cycle is divided into 2 phases.

(i) Interphase (a period of preparation for cell division)

(ii) M phase (the actual period of cell division).

The interphase cell is metabolically quite active. Interphase is the long nondividing phase further divided into G₁, S and G_2. It occupies 75 to 95% of entire cell division time.

Liver fluke has an incomplete alimentary canal.

Bt genes, RNAi genes and Cry genes occur naturally in living organisms.

Bt toxic gene of bacterium Bacillus thuringiensis has been cloned from bacteria, and expressed in plants, to provide resistance to insects without the need of insecticides. The choice of genes depends upon the crop and the targeted pest as most Bt toxins are insect group specific. The toxin is coded by a gene named Cry.

RNAi takes place in all eukaryotic organisms as a method of cellular defence. This method involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA (silencing).