OSMOSIS/DIFFUSION

During osmosis

• water moves from high to low concentration

• large or oddly shaped molecules move across a cell membrane

• water moves when energy is used

• proteins are built

Answer explanation

During osmosis, water moves from an area of high concentration to an area of low concentration. This process does not require energy and is essential for maintaining cell balance.

In the given scenario what will happen?  An egg is placed in pure water for 48 hours.

• The egg will gain water and swell.

• Water will move in and out of the cell equally, and the cell with neither shrink nor swell.

• The egg will lose water and shrink.

Answer explanation

When an egg is placed in pure water, osmosis occurs, causing water to move into the egg. This results in the egg gaining water and swelling, as the concentration of solutes inside the egg is higher than in the surrounding water.

The picture below is an example of _________________.

• osmosis

• isotonic

• diffusion

• active transport

Answer explanation

The picture illustrates diffusion, which is the movement of molecules from an area of higher concentration to an area of lower concentration. This process does not require energy, distinguishing it from active transport.

Passive transport requires no

• concentration gradients

• osmosis

• motion

• energy

Answer explanation

Passive transport does not require energy, as it relies on the natural movement of molecules down their concentration gradient. This process occurs without the input of energy, unlike active transport.

_______ regulates what enters and leaves a cell.  

• Cell Membrane

• Nucleus

• Mitochondria

• Cytoplasm

Answer explanation

The cell membrane, also known as the plasma membrane, regulates what enters and leaves a cell, maintaining homeostasis. It acts as a barrier and selectively allows substances to pass through, unlike the nucleus, mitochondria, or cytoplasm.

Which way will the water molecules move during osmosis?

• Out of the cell, so the cell shrinks.

• Out of the cell, so the cell swells.

• Into the cell, so the cell shrinks.

• Into the cell, so the cell swells.

Answer explanation

During osmosis, water moves out of the cell when the surrounding solution is hypertonic. This causes the cell to lose water, leading to shrinkage.

What is diffusion?

• when molecules move 

• when molecules move from a high concentration to a low.

• no movement 

• molecules move everywhere

Answer explanation

Diffusion is the process where molecules move from an area of high concentration to an area of low concentration, resulting in even distribution. This is why the correct answer is 'when molecules move from a high concentration to a low.'

Which diagram best shows the end result of diffusion?

• F

• G

• H

• J

Answer explanation

Choice J best illustrates the end result of diffusion, showing a uniform distribution of particles throughout the space, which is the key characteristic of diffusion. Other choices do not represent this balanced state.

 An animal cell placed in a hypertonic (salty) solution will

• Stay the same

• Shrink- get smaller

• Swell- get bigger

Answer explanation

An animal cell in a hypertonic solution loses water to the surrounding environment, causing it to shrink. Therefore, the correct answer is that the cell will shrink and get smaller.

What is the definition of  Selective Permeability?

• The movement of materials across the cell membrane that requires NO ENERGY from the cell.
  

• The movement of materials through (or across) the cell membrane
  

• The ability of the cell membrane to allow some things to pass through while preventing other things from passing through.

• The movement of molecules from an area of high concentration to a area of low concentration 
  

Answer explanation

Selective permeability refers to the cell membrane's ability to allow certain substances to pass while blocking others, ensuring that essential materials enter and harmful substances are kept out.