Biology Questions

ddNTPs - Dideoxynucleotides and abbreviated as ddNTPs.

They are chain-elongating inhibitors of DNA polymerase, used in the Sanger method for DNA sequencing.

They have a hydrogen at the 3’ carbon of the ribose sugar.

In flowering plants one sperm nucleus fertilizes the egg and the other sperm nucleus fuses with two other nuclei found within the ovule, thus forming triploid endosperm.

Hence, double fertilization is unique to flowering plants.

The central nervous system ( brain and spinal card ) are invested with the meninges which nourish and protect the system .This again is enclosed inside a bony box which has the skin above it

RNA is not a lipid among the given options.

A lipid is a substance of biological origin that is soluble in nonpolar solvents. It comprises a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids.

The persons with 'O' blood group do not have antigens in the red corpuscles. So that blood will not cause agglutination of corpuscles if mixed with any type of blood. So group 'O' persons are called universal donors.

Capillaries Tiny blood vessels connecting arteries to veins. These blood vessels carry oxygen

and nutrients to individual cells. Capillaries are the smallest blood vessels in the body, and have

walls only one or two cells thick. (Their diameter is 5 to 10 micrometers, or 5 to 10 millionths of

a meter.)

Capillaries connect arterioles and venules, which are the smaller extensions of the larger arteries and veins.