Questions

Enzymes play an essential role in each living cell of our body. Enzymes are globular proteins that control biological reactions. These are of two types.

1. Intracellular enzymes

2. Extracellular enzymes

Intracellular enzymes are found inside the cell.

Extracellular enzymes act outside the cell.

Enzymes are produced by exocrine glands.

Digestive enzymes of diverse specificities are secreted by the salivary glands, stomach, pancreas, and the small intestine.

A method for providing fault tolerance by using multiple hard disk drives

The size of the pupil of the automatically adjusts itself according to the intensity of light passing through it; if the intensity is more, the size is less, if less, it is more. So in our case the pupil should dilate i.e , increase in size to be able to see in the dark. This switchover takes some time. But here the entry into the dark room is immediate. So the eye has no time to adjust itself and hence is not able to see at all for a while. 

The USSR( now a Common Wealth of Independent States) is spread over Europe and Asia

Detroit is the largest and most populous city in the U.S. state of Michigan. It is famous for Automobile Industries and is also known as MOTOR CITY.

NETBIOS is a programming interface that allows I/O requests to be sent to and received from a remote computer and it hides the networking hardware from applications.

NETBEUI is NetBIOS extended user interface. A transport protocol designed by microsoft and IBM for the use on small subnets.

In chemistry, the term transition metal has three possible meanings: The IUPAC definition defines a transition metal as "an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete d sub-shell".

Any of the set of metallic elements occupying a central block (Groups IVB–VIII, IB, and IIB, or 4–12) in the periodic table, e.g. iron, manganese, chromium, and copper. Chemically they show variable valency and a strong tendency to form coordination compounds, and many of their compounds are coloured.

Here in the given options, only iron (Fe) is a transition metal since Strontium is an alkaline earth, arsenic is a metalloid, hydrogen is (normally) a diatomic gas.