All High School Biology Resources
Example Questions
Example Question #71 : Common Cell Structures
Which structures are responsible for breaking down proteins, nucleic acids, lipids, and carbohydrates?
Mitochondria
Flagella
Lysosomes
Cytoskeleton
Lysosomes
Lysosomes are membrane-bound organelles that contain digestive enzymes which break down all four types of macromolecules. The mitochondria is responsible for synthesis of the majority of the cell's energy in the form of ATP. The cytoskeleton maintains cell shape and provides a "freeway" for transporting substances within the cell. Flagella are proteinaceous structures that aid in cell motility.
Example Question #72 : Common Cell Structures
Which is not part of the cell theory?
Every organism is composed of at least one cell
Cells are generated spontaneously
The smallest living things are cells
New cells only come from pre-existing live cells
Cells are generated spontaneously
Cell theory consists of three statements: all organisms considered to be alive are made of cells, the cell is the simplest unit of a living thing, and all cells arise from other live cells. Thus, the idea that cells arise spontaneously is not part of cell theory.
Example Question #72 : Cell Biology
In several important biochemical mechanisms, the cell's enzyme requires a particular enantiomer of a substrate in order to carry out the reaction. Why is this true?
Enzymes are highly specific in terms of shape in order to carry out a reaction
Enzymes lower the activation energy of a biochemical reaction
The cell's enzymes have evolved to prefer a particular enantiomer becuase it is more abundant
None of the other answer choices
Enzymes are highly dependent on temperature
Enzymes are highly specific in terms of shape in order to carry out a reaction
This question requires the knowledge that several biological substrates come in enantiomer forms (think of them as your right and left hands). Effectively these molecules come in two mirror/opposite configurations. Having the right configuration or shape is crucial for enzymes to catalyze reactions due to highly shape-specific bnding sites on substrate molecules. Thus, the correct answer to this qustion is "enzymes are highly specific on shape in order to carry out a reaction." The other answer choices, except "the cell has evolved to prefer a particular enantiomer becuase it is more abundant," do not allude to this underlying concept of why cells need a particualr enantiomeritic form/shape in order to carry out a reaction and are not correct. Last, enantiomers typically appear in similar oncentrations due to equal potential energies; therefore, it is unlikely and incorrect to expect the cell to develop an evolutionary preference based upon abundance.
Example Question #73 : Common Cell Structures
The central vacuole is not responsible for which of the following?
Digestion
Cell rigidity
Storage of waste
Aerobic respiration
Storage of water
Aerobic respiration
The plant central vacuole is a membrane bound organelle containing water and other enzymes. The central vacuole functions as a storage space in the center of the plant cell, and is responsible for many functions including digestion, isolating harmful materials, maintaining internal hydrostatic pressure (turgor), storage of water and small molecules, cell rigidity, and more. Aerobic respiration occurs in the mitochondria, where:
Example Question #74 : Common Cell Structures
Which of the following is found at the head of a sperm cell?
The acrosome
The terminal disc
A dense concentration of mitochondria
The tail
The acrosome
The tail, terminal disc, and most mitochondria are found near the rear of the sperm cell (in order to facilitate movement). The acrosome is a cap-like organelle (derived from the Golgi apparatus) that develops over the anterior half of the head in the sperm cells of many animals. The acrosome contains digestive enzymes which allows the break down of the outer membrane of the ovum (zona pellucida). In short, the acrosome is located at the head of the sperm cell and allows penetration of the egg cell.
Example Question #75 : Common Cell Structures
What is the main function of lysosomes?
Sorting and shipping proteins
Synthesizing proteins
Digesting proteins and lipids
Producing messenger RNA
Digesting proteins and lipids
Lysosomes serve as the "clean-up" crew in the cell, digesting excess proteins and lipids in the cell and breaking them down into smaller molecules. Lysosomes do not produce messenger RNA, which is produced in transcription byDNA. Ribosomes synthesize proteins, and the Golgi Apparatus sorts and ships proteins.
Example Question #76 : Common Cell Structures
A human sperm cell possesses a device that propels it forward known as a __________.
cytoplasm
flagellum
smooth endoplasmic reticulum
cilia
flagellum
The flagellum (plural flagella) is the whip-like structure on the end of a human sperm cell that propels it forward. Cilia are the hair-like structures on membranes on cells that aid in movement. Smooth endoplasmic reticulum (ER) is the organelle involved in synthesizing lipids and detoxifying substances. Cytoplasm is the jelly-like substance throughout the cell.
Example Question #77 : Common Cell Structures
Which of the following is not considered part of the eukaryotic endomembrane system?
Vesicle
Cell membrane
Mitochondria
Golgi body
Endoplasmic reticulum
Mitochondria
The endomembrane system is a collection of membranes making up a cell that are connected either physically or via transport using vesicles. One of its main functions is to package and "ship" things made in the cell to other places in the organism, such as hormones like insulin. In order to do this, different organelles with different functions are necessary, just like there are different people with different jobs who make sure a package is mailed to the proper place.
Example Question #78 : Common Cell Structures
Where is ribosomal RNA formed?
Nucleolus
Golgi apparatus
Mitochondria
Smooth endoplasmic reticulum
Rough endoplasmic reticulum
Nucleolus
The nucleolus is a specialized region found within the nucleus. It is responsible for synthesizing ribosomal RNA (rRNA), while transcription of messenger RNA (mRNA) and transfer RNA (tRNA) occurs in parts of the nucleus other than the nucleolus.