Explanation

The organelle that is not present in animal cells is the Plastid. 

Plastids, including chloroplasts, are organelles specific to plant cells and are not found in animal cells. 

Endoplasmic Reticulum:

Present in both animal and plant cells. 

Ribosome:

Present in all cells, as they are the site of protein synthesis. 

Mitochondria:

Present in most animal cells, responsible for generating energy. 

Explanation

If a vector is given as →A = xi, its magnitude is simply |→A| = √(x²) = x (assuming x ≥ 0).

Explanation

 The term for a sentence that expresses strong emotion or surprise is an exclamatory sentence.

These sentences typically end with an exclamation mark (!) and convey feelings such as excitement, anger, happiness, or admiration. 

Explanation

Treponema pallidum is a spirochete bacterium that causes syphilis.

This is the correct answer as confirmed by multiple sources. 

Explanation

The breakdown of two molecules of glucose in aerobic respiration will produce 12 molecules of carbon dioxide (CO2). 

The balanced chemical equation for aerobic respiration shows that one molecule of glucose (C6H12O6) produces six molecules of carbon dioxide (6CO2).

Therefore, if two molecules of glucose are broken down, the total number of CO2 molecules produced will be:

2 molecules of glucose * 6 molecules of CO2 per glucose = 12 molecules of CO2. 

Explanation

Light intensity refers to the amount of light energy reaching a plant surface per unit time.

This is a crucial factor for photosynthesis as it directly determines how much energy is available to drive the process

Higher light intensity leads to a higher rate of photosynthesis until the plant reaches its maximum capacity. 

Explanation

 A chromosome is a long, thread-like structure made up of DNA, and within that DNA are smaller segments called genes. 

Explanation

All gases will start effusing at the same time, but the rate of effusion depends on their molar mass (Graham’s Law).  

Lighter gases like H₂ effuse faster than heavier ones like Cl₂.

Explanation

 When a body moves against the force of friction on a horizontal plane, the work done by the body is negative.

This is because work is defined as the dot product of force and displacement,

And when moving against friction, the force of friction acts in the opposite direction to the displacement of the body,

Resulting in an angle of 180 degrees between them. 

Explanation

 Energy = Power × Time = 40 W × 3600 s = 144000 J