STAAR Training

Normal cells that have a contact inhibition feedback mechanism that prevents the cells from replicating when other cells are touched. A diagram of cells with contact inhibition and cells without contact inhibition is shown. Which statement best describes what will happen to cells in an organism that lack contact inhibition?

• The cells will continue to grow, causing a tumor in the body.

• The cells will replicate normally, replacing body cells that die.

• The cells will replicate until the food supply for each cell is used, causing each cell to die.

• The cells will stop replicating once one layer is produced, as other body cells will crowd them out.

Answer explanation

Contact inhibition is a mechanism that stops the cell cycle and prevents cells from performing replication/proliferation and growth. The cells in an organism that lack contact inhibition will continue to replicate/proliferate and grow, and potentially lead to the development of tumors.

Tags

NGSS.HS-LS1-3

What type of material should the wires be made out of so that they best conduct electricity?

• Nonmetal

• Metalloid

• Metal

• Ceramic

The archer above shoots an arrow toward a target. Which object has the GREATEST kinetic energy?

• archer

• bow

• arrow

• target

Tags

NGSS.MS-PS3-1

What is the average speed of the person during the first 5 seconds?

• 0 m/s

• 1 m/s 

• 3 m/s

• 6 m/s 

Tags

NGSS.MS-PS3-1

The diagram above shows changes in a desert rock formation over time. The changes in the rock formation occurred as rock was worn away by wind-blown dust. Which type of energy is MOST responsible for wearing away the rock?

• kinetic energy

• radiant energy

• potential energy

• chemical energy

Tags

NGSS.MS-ESS2-2

NGSS.MS-PS3-5

What does this graph represent?

• Constant Speed

• Acceleration

• Not moving

Tags

NGSS.MS-PS3-1

What is the chemical formula for water?

Tags

NGSS.MS-PS1-1

Which of the following is a renewable energy source?

• Coal

• Natural Gas

• Solar Energy

• Nuclear Energy

What is the acceleration due to gravity on Earth?

• 9.8 m/s^2

• 8.9 m/s^2

• 10.5 m/s^2

• 7.8 m/s^2

Which organelle is known as the powerhouse of the cell?

• Nucleus

• Mitochondria

• Ribosome

• Endoplasmic Reticulum

Tags

NGSS.MS-LS1-2