Explanation

• Animal cells do not have chloroplasts, as they are not capable of photosynthesis.
• Animal cells also do not have a cell wall, unlike plant cells and some other organisms.

The components of an animal cell:

• Cell Membrane
• Cytoplasm
• Small Vacuole
• Nucleus
• Chromosomes

Explanation

 Ostia are small pores on the sponge's body that allow water to flow in, leading to the central cavity called the spongocoel. 

Explanation

Most coenzymes are actually vitamins or derived from vitamins, meaning they are essential organic compounds needed in small amounts for normal metabolism

Explanation

Endometriosis is a condition where tissue similar to the lining of the uterus grows outside the uterus.

This tissue can cause pain and infertility, primarily in women.

There is very strong evidence linking endometriosis to female infertility.

Studies show that a significant portion of women with infertility also have endometriosis.

While endometriosis can rarely occur in men, it is not considered a significant cause of infertility in males. 

Explanation

 The proper term for "X" is Plane of symmetry.

A plane of symmetry is an imaginary plane that divides a crystal into two halves, where each half is the mirror image of the other. 

Explanation

 When a sound wave moves from one medium to another, the quantity that remains the same is its frequency. 

The frequency of a sound wave is determined by the source of the sound and doesn't change when it enters a different medium.

However, the wavelength and speed of the wave can change depending on the properties of the new medium. 

Explanation

A liquid crystal is a state of matter that exhibits properties of both liquids and crystals.

It requires the molecules to have a specific structure, often long and rigid, to form ordered phases.

While soap can form structures similar to liquid crystals when mixed with water (forming micelles), pure soap is not a liquid crystal.

The other options listed, DNA, cholesteryl format, and engine oil, can all exhibit liquid crystal properties under certain conditions. 

Explanation

Beta particles are high-energy electrons or positrons that interact frequently with air molecules.

These collisions cause them to change direction randomly, resulting in a zigzag or erratic path. 

Explanation

If two streams of protons move parallel to each other in the same direction, they repel each other. 

Protons are positively charged particles, and according to Coulomb's law, particles with the same charge repel each other.

This repulsive electrostatic force dominates between the protons, causing them to push away from each other. 

Explanation

Alveoli:

Bronchioles terminate in tiny air sacs called alveoli.

These are the primary sites for gas exchange in the lungs. 

Alveolar sac:

Alveoli are clustered together to form alveolar sacs

These sacs are the functional units of the lung where oxygen and carbon dioxide exchange occurs.