Biology Test 151

Lower concentrations of zinc increased both plant growth and the biosynthesis of tryptophan and auxins. The finding that zinc acts simultaneously on the biosynthesis of auxins and gibberellins is also evidence for the common action of growth substances of various chemical types on plant growth.
Hence, the correct option is (B).

Overwintering plants secrete antifreeze proteins (AFPs) to provide freezing tolerance. These proteins bind to and inhibit the growth of ice crystals that are formed in the apoplast during subzero temperatures. Antifreeze activity has been detected in more than 60 plants and AFPs have been purified from 15 of these, including gymnosperms, dicots and monocots.

Hence, the correct option is (C).

Hypochondriasis or hypochondria is a condition in which a person is excessively and unduly worried about having a serious illness. An old concept, the meaning of hypochondria has repeatedly changed. It has been claimed that this debilitating condition results from an inaccurate perception of the condition of body or mind despite the absence of an actual medical diagnosis.

Hence, the correct option is (A).

In eukaryotes, the kinetochore is a proteinaceous multi-subunit assembly whose main function is to generate load-bearing attachments of sister chromatids (the replicated chromosomes held together by the protein complex cohesin) to spindle microtubules during cell division (mitosis or meiosis).
Hence, the correct option is (B).

Oxygen is poorly soluble in plasma so that less than 2 percent of oxygen is transported dissolved in plasma. The vast majority of oxygen is bound to hemoglobin, a protein contained within red cells.

Hence, the correct option is (B).

Anti-Müllerian hormone (AMH) is a functional marker of fetal Sertoli cells. The germ cell number in adults depends on the number of Sertoli cells produced during perinatal development. Recently, AMH has received increasing attention in the research of disorders related to male fertility. 

Hence, the correct option is (D).

To begin transcribing a gene, RNA polymerase binds to the DNA of the gene at a region called the promoter. The DNA opens up in the promoter region so that RNA polymerase can begin transcription. Each gene (or, in bacteria, each group of genes transcribed together) has its own promoter.
Hence, the correct option is (B).

In C₄ plants, the photosynthesis takes place in a chloroplast of a thin-walled mesophyll cell and a 4-carbon acid is handed off to a thick-walled bundle sheath cell where the Calvin cycle occurs.

Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO₂). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain.

Hence, the correct option is (D).

Lion-tailed Macaques may be found at elevations of about 1500 metres in evergreen and semi-evergreen monsoon forests with broadleaf trees. Endemic to India, they are found in the Western Ghats in the South-West. Body Length – 46 to 61 cms. Weight – Males weigh between 9 to 11 kgs and females weigh between 7 to 8 kg. it's one of the endangered animals.

Hence, the correct option is (B).

Leaf tip tendril is the modified leaf or leaf part which is found in the weak-stemmed plants. They provide mechanical support to the plant and help it in climbing. The tendrils develop from the apex of the developing leaf, as in Gloriosa. This type of leaf apex is known as cirrhose.

Hence, the correct option is (C).