Question

1 read the following statement. animal cells need to make more hormones and vitamin d than plant cells do. which sentence from the article best supports the statement above? (a) every living thing, including plants, animals and microbes, could not exist if their cells lacked cell membranes. (b) lipids include fats, hormones, oils and phospholipids, which make up the cell membrane (c) in general, animal cell membranes have a lot of cholesterol compared to plant membranes. (d) animal cells lack a cell wall and only contain a plasma membrane. 2 read the following paragraph from the section cell membrane components. the cell membrane is semipermeable, meaning that it allows certain molecules to pass through the membrane and enter the cell. for example, transport proteins, which are embedded in the membrane, move nutrients into the cell and move toxic substances out of the cell. other proteins protrude from the membrane, allowing them to interact with other cells. these proteins include glycolipids, which are made of carbohydrate sugars and lipids, and glycoproteins, which are made of carbohydrate sugars and proteins. which idea is best supported by this paragraph? (a) cell membranes prevent toxins from entering the interior of the cell it protects. (b) proteins inside the cell consume nutrients and other molecules to create energy. (c) glycoproteins and glycolipids are the two main types of transport proteins inside a cell. (d) a completely impermeable cell would be unable to perform essential functions. 3 which of the following topics is emphasized in the text of the article, but not in image 2? (a) hydrophobic tails in phospholipids pair with other hydrophobic tails when they come into contact. (b) a hydrophilic head is one of the main components that form the structure of a phospholipid. (c) the heads and tails of phospholipids are comprised of different chemical compounds. (d) a phospholipid is a type of lipid that has both hydrophilic and hydrophobic components. 4 read the following selection. cells also have specialized parts called organelles that perform specific tasks inside the cell. some organelles, such as the nucleus and mitochondria, are protected by their own membranes. these membranes are similar in structure to the cells plasma membrane but have a different composition of proteins and lipids. based on selection and the information in image 3, which of the following predictions is most reasonable? (a) the plasma membrane of a cell is held together by cholesterol. (b) organelles are removed from the cell through transport proteins. (c) the nucleus and mitochondria exist in the cytoplasm of the cell. (d) carbohydrates protect the nucleus of a cell by forming a membrane.

Explanation:

1. Question 1:

• Hormones are lipids. Cholesterol is a lipid. If animal cell membranes have more cholesterol (a lipid) than plant cell membranes, and lipids include hormones, this supports the statement that animal cells need to make more hormones (and vitamin D, which is also a lipid - related molecule as it is derived from cholesterol in animals).

1. Question 2:

• The cell membrane is semi - permeable (allows certain molecules in and out). If it were completely impermeable (unable to let any molecules in or out), it couldn't perform functions like taking in nutrients (via transport proteins) or interacting with other cells (via protruding proteins).

1. Question 3:

• Image 2 focuses on the cell membrane allowing molecules through (with transport proteins etc.). The text about phospholipids in the article (not in Image 2) mentions that hydrophobic tails in phospholipids pair with other hydrophobic tails. Image 2 does not show or discuss this interaction of hydrophobic tails in the context of phospholipid - phospholipid interaction.

1. Question 4:

• Organelles like the nucleus and mitochondria are in the cell. The cell has cytoplasm (the jelly - like substance inside the cell membrane). Since the nucleus and mitochondria are part of the cell (but protected by their own membranes), they must exist in the cytoplasm.

Answer:

1. C
2. D
3. A
4. C