Science Final Review

A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly. What is the CONTROL GROUP?

• 1 paper clip

• 2 paper clips

• 3 paper clips

• 0 paper clips

Answer explanation

The control group is the baseline for comparison. In this experiment, the control group is the paper airplane with 0 paper clips, as it allows the student to observe the effect of adding mass without any additional weight.

Which sequence of terms is in the correct order from simplest to most complex?

• cells → tissues → organs → organ systems

• tissues → organisms → cells → organ systems

• cells → tissues → organ systems → organs

• organs → organisms → organ systems → cells

Answer explanation

The correct order from simplest to most complex is: cells (basic unit of life) → tissues (groups of cells) → organs (groups of tissues) → organ systems (groups of organs). Thus, the correct choice is cells → tissues → organs → organ systems.

This structure that allows particles to enter and exit the cell is called the ______.

• Cytoplasm

• Cell membrane

• Cell wall

• Molecule

Answer explanation

The cell membrane is the structure that regulates the entry and exit of particles in and out of the cell, maintaining homeostasis. It is selectively permeable, unlike the cytoplasm or cell wall, which serve different functions.

The cell theory states that

• all cells have a vacuole that contain genetic information

• all living organisms are composed of cells that arise from preexisting cells

• all cells regenerate and contain the same basic structures

• organisms that lack certain organelles reproduce by binary fission

Answer explanation

The cell theory states that all living organisms are composed of cells and that these cells arise from preexisting cells, emphasizing the fundamental role of cells in life.

Which letter indicates a cell structure that is the site of photosynthesis in plant cells?

• A

• B

• C

• D

Answer explanation

The correct choice is C, which indicates chloroplasts, the cell structures in plant cells where photosynthesis occurs. Chloroplasts contain chlorophyll, the pigment that captures light energy for this process.

Molecules are transported within animal and plant cells using a system of passageways that make up the

• endoplasmic reticulum

• mitochondria

• ribosomes

• chloroplast

Answer explanation

The endoplasmic reticulum (ER) is a network of membranes that facilitates the transport of molecules within cells. It plays a crucial role in synthesizing proteins and lipids, making it essential for cellular function.

Within a cell, DNA is mainly found in the

• cell wall

• plasma membrane

• ribosomes

• chromosomes

Answer explanation

Within a cell, DNA is primarily organized into structures called chromosomes. These chromosomes contain the genetic information necessary for cell function and inheritance, making them the correct answer.

The diagram below represents a plant cell. Which cell structure stores materials?

• A

• E

• H

• D

Answer explanation

In a plant cell, structure H represents the vacuole, which is responsible for storing materials such as nutrients and waste products. This makes H the correct choice for the structure that stores materials.

Which organelles are usually found in both plant and animal cells?

• cell walls

• large vacuole

• mitochondria

• chloroplasts

Answer explanation

Mitochondria are the powerhouse of both plant and animal cells, providing energy through respiration. In contrast, cell walls and chloroplasts are unique to plant cells, and large vacuoles are typically larger in plants.

Cellular respiration occurs within the organelle known as the

• lysosome

• nucleus

• mitochondria

• vacuole

Answer explanation

Cellular respiration occurs in the mitochondria, which are known as the powerhouse of the cell. They convert nutrients into energy, unlike lysosomes, the nucleus, or vacuoles, which have different functions.