8.L.5.1

Which energy transformation occurs during active transport in a cell?

• chemical energy -> mechanical energy

• light energy -> chemical energy

• kinetic energy -> potential energy

• mechanical energy -> electrical energy

Which two statements in the table are true for plant cells and FALSE for animal cells?

• 2 and 3

• 1 and 2

• 3 and 4

• 4 and 1

The endoplasmic reticulum in a eukaryotic cell is made of folded membranes. Which molecules does a cell need from food to make these membranes?

• 1 and 2

• 1 and 3

• 2 and 3

• 2 and 4

A lion and a crocodile are both large animals, but a lion has to eat much more than a crocodile of the same mass to survive. Which statement BEST explains the difference?

• The lion has to generate thermal energy and the crocodile does not.
• The crocodile eats larger prey than the lion can.
• The lion can store much more food than the crocodile can.
• The crocodile uses its food more efficiently than the lion does.

A scientist uses a special chemical marker to label some amino acids. He follows the marker until it becomes part of a large molecule in a cell. Which molecule does he find the chemical marker on? (a)  

• an enzyme in a lysosome
• a lipid in a membrane
• a polysaccharide in a cell wall
• a DNA molecule in a mitochondrion

A student wrote the following claim on a homework assignment: “Eukaryotic cells need more lipids than prokaryotic cells.” Which statement below provides the BEST support for her claim?

• Eukaryotic cells contain membrane-bound organelles.
• Eukaryotic cells have a nucleus.
• Eukaryotic cells make up multicellular organisms.
• Eukaryotic cells perform cellular respiration.

After a person eats, the food is converted into energy by (a)  

• cells.
• muscles.
• tissues.
• bones.

Animal cells obtain energy by

• absorbing nutrients.
• processing sunlight.
• growing.
• dividing.

Both prokaryotes and eukaryotes have small, free-floating organelles. The cell makes these organelles from nucleic acids and amino acids found in food. Without these organelles, the cell could not make proteins. What are these organelles called?

• ribosomes
• chloroplasts
• mitochondria
• vesicles

Corn is a popular feed for pigs because it is high in carbohydrates. However, it has a very low level of the amino acid lysine, so farmers usually add high-lysine feeds to the corn. Which statement BEST explains why lysine levels in pig feed are important?

• Cells stop making protein when their supply of lysine runs out.
• Cells stop replicating DNA when their supply of lysine runs out.
• Cells stop processing carbohydrates when their supply of lysine runs out.
• Cells stop repairing cell membranes when their supply of lysine runs out.