Explanation

A pair of two equal and unlike parallel forces (i.e. forces equal in magnitude, with lines of action parallel to each other and acting in opposite directions) is known as a couple.

As a matter of fact, a couple is unable to produce any translatory motion (i.e., motion in a straight line).

Explanation

Mass 1,  = 1000 kg

Mass 2,  = 1000 kg

Distance between the spheres, r = 0.5 meters

Gravitational force is the force of attraction between two bodies.

The force of gravitation is inversely proportional to the square of the distance between the bodies and directly proportional to the multiplication of masses of two bodies.

It is given as:

F= G (m1.m2/r^2)

F = 6.67 *n10^11 (1000 * 1000/ 0.5 * 0.5)

F = 2. 67 * 10^-4 N

Explanation

The name “red tide” comes from the fact that the overgrowth of algae can cause the colour of the water to turn red.

The red tides caused by the dinoflagellate Gonyaulax (unicellular algae) are serious

because this organism produces powerful toxins (saxitoxin and gonyautoxins) that can kill aquatic organisms.

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Cephaleuros virescens which is Green algae

Fucus is a genus of brown algae.

Explanation

Explanation

Echidnas and platypus are the only egg-laying mammals, known as monotremes.

Explanation

Plasmids are replicons that are maintained as discrete, extrachromosomal genetic elements in bacteria.

Explanation

In Riccia sporophyte is embedded.

The spores are formed inside the sporophyte.

The spores are dispersed by the decay of surrounding thallus tissue.

The spore is the first cell of gametophytic

Explanation

A facultative parasite is an organism that is normally a saprophyte (lives on dead organic matter) but can live as a parasite under favorable conditions.

Unlike obligate parasites, they do not require a host to complete their life cycle and can survive independently. 

Explanation

Mature vascular bundles have a canal called the carinal canal.

It is one of a number of longitudinal channels inside the metaxylem and is formed by the disintegration of the protoxylem.

Commonly seen in Equisetum.

Explanation

In facilitated transport, also called facilitated diffusion,

material moves across the plasma membrane with the assistance of transmembrane proteins down a concentration gradient (from high to low concentration) without the expenditure of cellular energy.