Science Unit

Serena knows that scientists use physical similarities to classify organisms. She studies the figures of four different organisms. Which two organisms should Serena conclude are most closely related?

• 1 and 2

• 1 and 3

• 2 and 3

• 2 and 4

Eukaryotic cells and prokaryotic cells have some parts in common. Which of the following pairs of parts would you find in both types of cells?

• cytoplasm and nucleus

• cell membrane and cytoplasm

• DNA and membrane-bound organelles

• cell membrane and membrane-bound organelles

Robert Hooke was the first person to describe cells. Which of the following instruments did he use to make his observations?

• 
• 
• 
• 

Cells use energy to carry out various cell processes. Which of the following molecules stores energy for the cell to use?

A.

• ATP

• DNA

• water

• chloroplast

In biology class, Zach observes cells. Each cell has a structure that separates the inside of the cell from the environment. Which structure is Zach observing?

• nucleus

• cytoskeleton

• cell membrane

• genetic material

Imagine a cell that has the shape of a cube with sides that are 3 cm long. Find the surface-area-to-volume ratio of this cell.

• 27 cm³

• 54 cm²

• 27 cm³ : 54 cm²

• 54 cm² : 27 cm³

Jemin is making a poster to compare unicellular organisms with multicellular organisms. She writes the following statements on her poster. Which of the following statements is not true?

• Unicellular organisms live longer.

• Multicellular organisms are larger.

• Unicellular organisms are made of just one cell.

• Multicellular organisms have cells that work together.

Gerard listed four levels of structural organization within multicellular organisms. He listed them in order from the smallest structure to the largest structure. Which of the following lists is correct?

• cells, tissues, organ systems, organs

• cells, tissues, organs, organ systems

• tissues, cells, organ systems, organs

• tissues, cells, organs, organ systems

What is the function of a cell’s nucleus?

A.

B.

C.

D.

• to hold DNA

• to hold organelles

• to hold cytoplasm

• to hold the cell membrane

Kayla summarizes the cell theory to her class. She states that all organisms are made up of one or more cells. Which pair of statements correctly completes her summary?

• All cells come from existing cells, and all cells have the same parts.

• All cells are the same size, and the cell is the basic unit of all organisms.

• The cell is the basic unit of all organisms, and all cells have the same parts.

• The cell is the basic unit of all organisms, and all cells come from existing cells.