Explanation

Vaccines are made from:

• Weakened or killed bacteria or viruses
• Small pieces of bacteria or viruses, like proteins or sugars
• Genetic material (DNA or RNA) from bacteria or viruses

These components stimulate an immune response, helping the body build immunity against specific diseases.

Explanation

• Ozone protects the Earth from harmful ultraviolet (UV) rays from the solar. with out the Ozone layer inside the atmosphere, existence on the earth could be very hard. plant life cannot live and grow in heavy ultraviolet radiation, nor can the planktons that serve as food for most of the sea existence.
• With a weakening of the Ozone Layer defend, human beings would be greater at risk of skin cancer, cataracts and impaired immune systems.
• Ozone can both shield and damage the Earth — it all depends on in which it is living. for example, if Ozone is present in the stratosphere of the ecosystem, it's going to act as a guard.
• however, if it is in the troposphere (about 10 km from the Earth's floor), Ozone is harmful. it's miles a pollutant that could purpose damage to lung tissues and plants. hence, an upset inside the ozone balance can have extreme outcomes

Explanation

Answer: D

The disease affects cattle, pigs, sheep, goats, and other ruminant ungulates. Intensively bred animals are more susceptible to disease than traditional breeds.

Explanation

The cross product (A × B) is a vector whose magnitude is given by:

| A × B | = |A||B| sinθ

Its direction follows the right-hand rule.

Explanation

The velocity of a photon is independent of its wavelength. 

The velocity of a photon is determined by the speed of light in a vacuum, which is a constant value (approximately 299,792,458 meters per second) and does not change based on the photon's wavelength or amplitude.

The speed of light is a fundamental constant of nature. 

Explanation

73.650 rounded up to one decimal place is 73.7.

When rounding up, if the digit to the right of the desired decimal place is 5 or greater,

You increase the digit in the desired decimal place by one.

Since 5 in the hundredth place is greater than or equal to 5, the tenths place digit (6) is increased to 7.

Explanation

The moon is a satellite because it moves around Earth.

Earth and the moon are called "natural" satellites.

Explanation

the kinetic energy of an object is the energy that it possesses due to its motion.

It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

Applying a force requires us to do work.

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2

ND18-4-2023

Explanation

Oxygen is the chemical element with the symbol O and atomic number 8. 

Explanation

Gas: No definite shape or volume – Expands to fill any container.

Example: Oxygen, CO₂.

Solid: Fixed shape and volume (e.g., iron).

Liquid: Fixed volume, no fixed shape (e.g., water).