Exams

Rafael Nadal defeated Daniil Medvedev in the men's singles title at the 2019 US Open. It was Nadal's 19th Grand Slam singles title, and fourth US Open title.

The number of protons is equal to the number of electrons. That is the number of positive charges is equal to the number of negative charges.

Desertification is a type of land degradation in which a relatively dry area of land becomes increasingly arid, typically losing its bodies of water as well as vegetation and wildlife.

Conversion of a grassland or an already arid land into a desert through indiscriminate human actions magnified by droughts.

Hence, forest improving to deserts is refers to desertification.

Any number which can be expressed as a fraction of two integers like P & Q as P/Q where Q is not equal to zero.

Every integer is a rational number since Q can be 1.

Hence, in the given options, 4 can be expressed as a simple fraction as 4/1. And all other options cannot be expressed as fractions.

Hence, 4 is a rational number in the given options.

All of the genetic information in a cell was initially thought to be confined to the DNA in the chromosomes of the cell nucleus.

It is now known that small circular chromosomes, called extranuclear, or cytoplasmic, DNA, are located in two types of organelles found in the cytoplasm of the cell.

These organelles are the mitochondria in animal and plant cells and the chloroplasts in plant cells.

Chloroplast DNA (cpDNA) contains genes that are involved with aspects of photosynthesis and with components of the special protein-synthesizing apparatus that is active within the organelle.

Mitochondrial DNA (mtDNA) contains some of the genes that participate in the conversion of the energy of chemical bonds into the energy currency of the cell—a chemical called adenosine triphosphate (ATP)—as well as genes for mitochondrial protein synthesis.

The One-word substitute for That which cannot be corrected is Incorrigible.

A substance that cannot be decomposed (broken down) into simpler substances by ordinary chemical means.

Examples: gold, iron, carbon, hydrogen, oxygen, nitrogen.

Material composed of only one kind of matter throughout (same atoms or same molecules).

Lines of latitude measure north-south position between the poles.

Lines of latitude are imaginary reference lines that describe how far north or south a location on the Earth is from the Equator. The equator is defined as 0 degrees, the North Pole is 90 degrees north, and the South Pole is 90 degrees south. Lines of latitude are all parallel to each other, thus they are often referred to as parallels.