Cell Theory

Bacteria are among the smallest organisms on Earth, while humans are among the most complex. What is the basic unit of life common to bacteria, humans, and all other living organisms?

• Carbohydrates

• Chloroplasts

• Organs

• Cells

Tags

NGSS.MS-LS1-1

NGSS.MS-LS1-2

Fred was observing a leaf and a rock with a microscope. Which part of the the cell theory might she be investigating?

• Cells come from pre-existing cells.

• Groups of cells join to form tissues.

• All organisms are made up of cells.

• Cells are the basic unit of life.

Tags

NGSS.MS-LS1-1

Cells are the smallest part of an organism that can carry out all of the life functions. Which part of the cell theory incorporates this idea?

• Cells can only be seen with a microscope.

• Cells are the basic unit of life.

• Only plants and animals are made of cells.

• New cells can be produced from pre-existing cells.

Tags

NGSS.MS-LS1-2

The cell theory is a scientific explanation about the characteristics of cells and living things. The discovery of cells occurred in the 1600s. Which piece of equipment might students in a science class use to investigate the cell theory?

• Hand lens

• Compound light microscope

• Electron microscope

• Scanning tunneling microscope

Tags

NGSS.MS-LS1-1

Before the Cell Theory, spontaneous generation was a widely accepted idea. Spontaneous generation was the idea that living things could be produced by non-living things. Which part of the cell theory BEST contradicts spontaneous generation?

• All living things are made of cells.

• Cells can form from decaying matter.

• Cells come from pre-existing cells.

• Cells are the basic unit of structure and function in organisms.

Many species of lizards are able to release their tails as a decoy for predators to chase after when in danger. The lizards are able to regenerate a tail later. Which is the BEST statement from the cell theory that explains how the lizard is able to regrow its tail?

• Lizards eat flies which are used to grow a tail.

• Lizards are made of atoms which produce new atoms to grow a tail.

• Lizards use energy from the sun to grow a tail.

• Lizards are made of cells which produce new cells to grow a tail.

Tags

NGSS.HS-LS1-4

Which scientist is known for famously naming the cell after tiny rooms in a monastery?

• Bill Nye

• Theodor Schwann

• Robert Hooke

• Aristotle

The earliest classification system was developed by Aristotle in the 4^th century B.C. This system classified all living things as either plants or animals. The two-kingdom system remained in place until 1866, when the kingdom Protista was created. What new information most likely led scientists to revise the existing classification system?

• The magnifying glass showed scientists that plants were made up of cells.

• The microscope showed that cells of plants and animals have different structures.

• The microscope enabled scientists to discover single-celled organisms.

• The telescope enabled scientists to see objects they could not view before.