Biology Test 134

Ferredoxin (Fd) is comprised of ubiquitous, small proteins containing one or two iron-sulfur clusters. These prosthetic groups contain iron and sulfur atoms, organized in three different types of centers: 2Fe–2S, 4Fe–4 S, and 3Fe–4S. The presence of the cluster(s) confers to the protein the property of absorbing light in the visible region. Fd solutions are thus reddish-brown in the oxidized state and fade upon reduction.

Hence, the correct option is (B).

Gibberellin is a hormone that replaces vernalisation. Vernalization is a period of cold treatment for plants, usually perennials or trees. Some plants won't bloom without it. In vernalization plants are exposed to low temperatures in order to stimulate flowering or to enhance seed production. The biennials form their vegetative body in the first year. Then they pass through the winter season and then produce flowers and fruits in the second year. By exogenous application of gibberellins, many biennials can be induced to behave like annuals and they no more require the natural chilling treatment for their flowering.

Hence, the correct option is (C).

Pollen wall comprises two principal layers, the inner intine, and outer exine. The intine is pectocellulosic in nature. A special feature of intine is the presence of beads, ribbons, or plates of enzymatic proteins particularly in the vicinity of germ pores. The exine is composed of sporopollenin which is derived from carotenoids by oxidative polymerization. it is resistant to physical and biological decomposition. Due to this, pollen walls are often preserved for long periods in fossil deposits.

Hence, the correct option is (D).

Monascus purpureus is used to produce Statin. Statins lower the blood cholesterol level by competitively inhibiting the enzyme responsible for the synthesis of cholesterol. Statins are bioactive molecules, produced by the yeast Monascus purpureus. These bioactive molecules have been commercialized as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for the synthesis of cholesterol.

Hence, the correct option is (D).

Polymers are broken down into monomers in a process known as hydrolysis, which means “to split water,” a reaction in which a water molecule is used during the breakdown. During these reactions, the polymer is broken into two components.  If the components are un-ionized, one part gains a hydrogen atom (H) and the other gains a hydroxyl group (OH) from a split water molecule. This is what happens when monosaccharides are released from complex carbohydrates via hydrolysis.

Hence, the correct option is (B).

Osteoporosis is a bone disease that occurs when the body loses too much bone, makes too little bone, or both. As a result, bones become weak and may break from a fall or, in serious cases, from sneezing or minor bumps. Osteoporosis means “porous bone.” Viewed under a microscope, healthy bone looks like a honeycomb.

Hence, the correct option is (B).

Typically, frogs lay eggs. This process usually occurs through external fertilization, where the female releases her eggs from her body into the water. Then, the male releases his sperm to fertilize them.

Hence, the correct option is (D).

An ectomycorrhiza is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobiont, and the roots of various plant species. Ectomycorrhizas form on the roots of around 70% of plant species, usually woody. Some polypeptides are only found when the fungus and plant have achieved symbiosis.

Hence, the correct option is (A).

Warburg effect is the inhibitory effect of high oxygen concentrations on photosynthesis. He was a German scientist, who reported in chlorella alga, that high O2 level inhibits the rate of photosynthesis. Various hypotheses have been put forward to explain the inhibitory effect of oxygen, commonly referred to as the Warburg effect.

Hence, the correct option is (A).