Directions: Read the passage below. Answer questions 1 – 5 and fill in the table on the next page.
A cell is a very small unit of life. Inside a cell are even smaller structures called organelles, which carry out specific functions within the cell. These organelles each have a specific job that they carry out to keep the cell alive.
The cell wall is a rigid layer of nonliving material that surrounds the cells of plants and some other organisms. A plant’s cell wall helps to protect and support the cell, keeping it strong and sturdy. The cell wall is made of a strong, flexible material called cellulose, and many materials can pass through it.
In cells that do not have cell walls, the cell membrane is the outside boundary that separates the cell from its environment. All cells have cell membranes. In cells with cell walls, the cell membrane is located just inside the cell wall. The cell membrane is selectively permeable. In other words, it controls what substances come into and out of a cell.
The nucleus is a large, oval structure that acts as the “brain” of the cell. You can think of the nucleus as the cell’s control center, directing cell activities. The nucleus is surrounded by a protective membrane called the nuclear envelope. Materials pass in and out of the nucleus through small openings or pores.
Inside the nucleus, there is genetic material in the form of DNA incorporated into chromosomes. The genetic material controls everything about an organism.
The cytoplasm is the region between the cell membrane and the nucleus. It is made mostly of water. Many cell organelles are found in the cytoplasm and this is where some chemical reactions take place. The mitochondria are known as the “powerhouse” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions. Small, grain-like bodies called ribosomes function as factories to produce proteins. Examples of these proteins are your enzymes, hormones, antibodies, hemoglobin, etc. Passageways called the endoplasmic reticulum carry these proteins and other materials from one part of the cell to another. Collections of sacs and tubes called Golgi bodies receive the proteins from the ER, package them and then distribute them to other parts of the cell. Large water-filled sacs called vacuoles are the storage areas of cells. They store food and other materials needed by the cell.
Animal cells contain centrioles that helps with cell division. Plants and other photosynthetic cells contain structures called chloroplasts that capture energy from the sunlight and convert it into glucose (food) for the cell.
Questions:
1.
Identify the small structures that carry out specific functions within the cell. _____________________________
2.
Describe the phrased selectively permeable.
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3.
Is the cytoplasm considered a cell organelle? Support your answer.
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4.
Identify the genetic material found inside the nucleus. _______________________________________________
5.
Describe the function of DNA. ___________________________________________________________________
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