A number of scientists made contributions to cell theory. Which scientist used a light microscope to observe cells in a slice of cork?

• Anton van Leeuwenhoek

• Matthias Schleiden

• Robert Hooke

• Theodor Schwann

Tags

HS-LS1-2, HS-LS1-3, HS-LS1-4

Which of the following statements is part of the cell theory?

• Cells are composed mostly of empty space.

• Cells are generally large enough for the unaided eye to see.

• All cells are produced from existing cells.

• Only animals are made up of cells.

Tags

HS-LS1-2, HS-LS1-3, HS-LS1-4

The cell is ​ (a)   ​ because it ​ (b)   .

• prokaryotic
• from a plant
• from an animal
• eukaryotic
• does not contain a nucleus
• contains DNA
• does not contain DNA
• contains a nucleus

Tags

HS-LS1-2, HS-LS1-3, HS-LS1-4

All cells contain cell membranes. Which of the following describes the composition of cell membranes?

• Cell membranes are composed of carbohydrate chains, which allow all materials to enter and leave the cell.

• Cell membranes are composed of cellulose, which provide rigidity for the cell.

• Cell membranes are composed of cytoplasm, which allows proteins to be excreted by the cell.

• Cell membranes are composed of lipid molecules, which provide a flexible structure.

Tags

HS-LS1-2, HS-LS1-3, HS-LS1-4

Multicellular organisms contain organ systems. Which of the following BEST describes the organs in an organ system?

• The organs in an organ system are made up of similar cells.

• The organs in an organ system are made up of similar tissues.

• The organs in an organ system work together to perform a specific function.

• The organs in an organ system work together to perform all the functions a multicellular organism needs to maintain homeostasis.

Tags

HS-LS1-2, HS-LS1-3, HS-LS1-4

White blood cells, called leukocytes, are very different in structure and function than red blood cells. White blood cells help fight infections, parasites, and bacteria. They do this by engulfing pathogens and synthesizing antibodies. Unlike red blood cells, white blood cells can reproduce. Which organelles, if any, must be present in white blood cells?

• White blood cells must have cell walls to enable them to engulf damaged red blood cells and pathogens by phagocytosis.

• White blood cells must have chloroplasts to produce the energy the cells need to perform their functions.

• White blood cells must have a rough endoplasmic reticulum so that large molecules, such as antibodies, can be synthesized.

• White blood cells cannot have organelles because they are prokaryotic cells.

Tags

HS-LS1-2, HS-LS1-3, HS-LS1-4

Which is NOT another name for the cell membrane?

• fluid mosaic model

• cell wall

• plasma membrane

• phospholipid bilayer

Tags

NGSS.MS-LS1-2

Homeostasis

• A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

• process of diffusion in which molecules pass across the membrane through cell membrane channels with concentration gradient

• A difference in the concentration of a substance across a distance. High in one place, low in another place.

• when the concentration is the same both inside and outside the cell, water still moves back and forth

Tags

NGSS.HS-LS1-3

Which type of biological macromolecule is the main component of the plasma membrane?

• carbohydrate

• lipid

• protein

• nucleic acid

Define plasma membrane

• lipid that helps minimize effects of temperature

• only on the outer surface of the plasma membrane and are attached to proteins or lipids; form distinctive cellular markers

• flexible boundary of a cell that separates a cell from its surroundings

• may extend partway into the plasma membrane, cross the membrane entirely, or be loosely attached to its inside or outside face