Cellular Homeostasis

Homeostasis and Cellular Processes

by Randa Buchanan

Multiple Choice

Homeostasis is necessary for cells to survive. What is the definition of homeostasis?

• The elimination of waste materials

• The division of cells to form new cells.

• The maintenance of a stable internal environment

• The process by which energy from the sun is used to make food

Multiple Choice

Molecules move in and out of a cell by diffusion. This image shows molecules both inside and outside of the cell. How will the molecules in this illustration move as a result of diffusion?

• into the cell

• out of the cell

• into another cell

• to the external environment

Multiple Choice

Cells grow and divide and make new cells by a process called____________

• homeostasis

• passive transport

• facilitated diffusion

• mitosis

Multiple Choice

In eukaryotic cells what must occur before a cell can grow and divied

• DNA must be copied

• DNA must be deleted

• DNA must be created

• nothing has to happen cells are magic and they just divide

Multiple Choice

What is NOT TRUE about the cell membrane

• It controls what enters and leaves the cell
• Semipermeable
• Phospholipid bilayer
• Contains digestive enzymes

Multiple Choice

What is diffusion?

• when molecules move from a low concentration to a high concentration 
• when molecules move from a high concentration to a low concentration.
• no movement 
• molecules move everywhere

Multiple Choice

Osmosis

• diffusion of water molecules through a semi-permeable mebrane from an area of low concentration to an area of high concentration
• the diffusion of particles from an area of high concentration to an area of low concentration
• diffusion of water molecules through a semi-permeable membrane from an area of high concentration to an area of low concentration
• the diffusion of particles from an area of low concentration to an area of high concentration

Active Transport

• Different from passive transport because it requires energy.

• Active transport is necessary to make particles move against their natural tendency.

• In active transport, particles move from less crowded (low concentration) to more crowded (high concentration) using ENERGY.

• ATP = ENERGY

Multiple Choice

What is the difference between active and passive transport?

• Active does not need energy and passive uses ATP (energy)

• Active uses ATP (energy) and passive does not need energy

• Active stores transport proteins and passive releases

• Active uses hormones and passive does not

Some materials can move in and out of the cell membrane easily.

-Passive Transport

Endocytosis

process by which the cell membrane envelops (engulfs) material that is too large to pass through the membrane and then pinches off inside the cell.

Exocytosis

The process by which the cell membrane removes material that is too large to pass through the membrane.

The material is surrounded by a membrane within the cell and then expelled by being pushed out of the cell.

Multiple Choice

Which cellular process removes large particles from the cell?

• endocytosis

• exocytosis

• diffusion

• osmosis

Multiple Choice

When cells form a vesicle to take in materials, which form of transport is occurring?

• endocytosis

• exocytosis

• diffusion

• osmosis

Multiple Choice

Living organisms can respond to their environment in order to maintain homeostasis. How might a tree maintain homeostasis during the winter months?

• shivers

• hibernates

• absorbs sun

• loses leaves