All AP Biology Resources
Example Questions
Example Question #26 : Understand Functions Of Organelles In The Cell
DNA can be found in which of the following cellular compartments of a eukaryotic cell?
Nucleus, mitochondria, chloroplasts and cytoplasm
Nucleus only
Nucleus, mitochondria, and chloroplasts
Nucleus and mitochondria only
Nucleus, mitochondria, and chloroplasts
While most of a cell's DNA is located in the nucleus, some DNA is found in the mitochondria and chloroplasts. The DNA found in plasmids supports the endosymbiotic theory. The cytoplasm of eukaryotes does not contain free floating DNA like in prokaryotes.
Example Question #141 : Cell Structures
What are extranuclear genes and what are their functions?
Extranuclear genes are genes located outside the nucleus that aid in DNA replication and protein synthesis
Extranuclear genes are additional genes within the nucleus that play a role in DNA replication and protein synthesis
Extranuclear genes are genes located outside the nucleus that do not play a significant role within the cell
None of these
Extranuclear genes are additional genes within the nucleus that do not play a significant role within the cell
Extranuclear genes are genes located outside the nucleus that aid in DNA replication and protein synthesis
Extranuclear genes, also known as cytoplasmic genes, are genes located outside the nucleus. They can be found in other parts of the cell, such as the mitochondrion, chloroplasts, and other plastids. Each of these organelles is thought to have originally been an independent prokaryotic cell, ingested by another cell, known as the endosymbiotic theory. Each of these organelles has its own DNA and works in cooperation within the nuclear DNA.
Example Question #141 : Cell Structures
Which of the following statements is true?
Ribosomes house chromosomes and synthesize DNA
The smooth endoplasmic reticulum synthesizes proteins
The Golgi apparatus synthesizes lipids and metabolizes carbohydrates ingested by the cell
The mitochondrion is responsible for breaking down damaged organelles and ingested substances
Peroxisomes are composed of enzymes that create hydrogen peroxide, which is then converted to water
Peroxisomes are composed of enzymes that create hydrogen peroxide, which is then converted to water
Ribosomes are organelles composed of two subunits of ribosomal RNA and proteins. There are two types: free ribosomes, which are found in the cytosol of the cell, and bound ribosomes, which are bound to the rough endoplasmic reticulum. Their primary purpose is to synthesize proteins. Messenger RNA will bring amino acids to the ribosomes, where proteins are then synthesized. The endoplasmic reticulum is an organelle that is composed of bounded tubules and sacs and is continuous with the nuclear envelope. It is composed of two parts: the smooth endoplasmic reticulum and the rough endoplasmic reticulum. The smooth endoplasmic reticulum synthesizes lipids, metabolizes carbohydrates, stores calcium, and detoxifies the cell of drugs and poisons. The rough endoplasmic reticulum, studded with ribosomes, aids in protein synthesis. The mitochondrion is bound by a double membrane; the inner membrane has many infoldings called cristae. This increases the surface area of the organelle and therefore increases productivity. Known as the “powerhouse of the cell,” the mitochondrion creates ATP for the cell through a process known as cellular respiration. Peroxisomes are specialized metabolic organelles bound by a single membrane. They contain enzymes that transfer hydrogen atoms from substrates to oxygen, producing hydrogen peroxide. Hydrogen peroxide is then converted to water. The Golgi apparatus is a stack of flattened membranous sacs. Its purpose is to modify proteins, carbohydrates, and phospholipids. Polysaccharides are also synthesized here. Besides synthesis and modification of these macromolecules, the Golgi apparatus also sorts products and sends them to other parts of the cell through vesicles.
Example Question #142 : Cell Structures
In the study of cell biology, organelles can be examined using __________.
a magnifying glass
an electron microscope
the naked eye
a light microscope
an electron microscope
Organelles, for the most part, are too small to be clearly defined by a simple light microscope. Although, larger organelles may be seen with a light microscope, they cannot be well-studied using them. An electron microscope can achieve remarkable magnification and resolution. Some electron microscopes can even resolve individual molecules or atoms. Also note that an egg (chicken, human, ostrich etc.) is a single cell. We can study the nucleus (yolk) with the naked eye, but this is a special case, and the question does not provide us any information that would make this a reasonable assumption.
Example Question #631 : Cellular Biology
What is the process by which a cell intakes extracellular fluid in "gulps" via tiny vesicles?
Phagocytosis
Exocytosis
Simple diffusion
Pinocytosis
Pinocytosis
Pinocytosis is the uptake of extracellular fluids. The cell accomplishes this by creating vesicles from the cell membrane around droplets of extracellular fluid and carrying them inside the cell. This process is unspecific in which substances it carries into the cell (not receptor-mediated). Exocytosis involves the same concept, but in the other direction (from inside the cell out). Simple diffusion does not involve the creation of vesicles, rather it involves substances freely diffusing through the plasma membrane from areas of high concentration to areas of low concentration without the net input of energy.
Example Question #632 : Cellular Biology
In eukaryotes the organelles that convert energy to forms the cells can use for work are __________.
mitochondria only
rough endoplasmic reticulum only
both mitochondria and chloroplasts
chloroplasts only
both mitochondria and chloroplasts
Both mitochondria and chloroplasts convert energy to work in eukaryotes. Mitochondria are the sites for the catabolic process that creates ATP in animals. In plants, chloroplasts are the sites of photosynthesis where solar energy is converted to chemical energy.
Example Question #633 : Cellular Biology
Cristae are located in __________.
the stroma
mitochondria
the plasma membrane
chloroplasts
mitochondria
Cristae are found in mitochondria. Mitochondria are enclosed by an envelope of two membranes. The inner membrane is convoluted with infoldings called cristae. This is an adaption that increases the surface area of the inner membrane of the mitochondria so that ATP synthesis can be maximized. The chloroplast equivalent of cristea are the thylakoid membranes. The stroma is the matrix equivalent of the chloroplast. The plasma membrane is not nearly as convoluted as the inner mitochondrial membrane.
Example Question #634 : Cellular Biology
What are the distinct, threadlike structures that contain the genetic information that is passed from one generation of cells to the next?
Chromosomes
Golgi apparatus
Smooth endoplasmic reticulum
Rough endoplasmic reticulum
Chromosomes
The chromosomes are the threadlike structures that contain genetic information. Rough endoplasmic reticulum is involved in protein synthesis. Smooth endoplasmic reticulum is involved in lipid synthesis. The Golgi apparatus is involved in modification and delivering of proteins within the cell and for secretion outside the cell.
Example Question #635 : Cellular Biology
Eukaryotic cells have this structure that is a network of protein filaments that helps the cell to maintain its shape.
RNA
DNA
Cytoskeleton
Smooth endoplasmic reticulum
Cytoskeleton
The cytoskeleton is a network of protein filaments in eukaryotic cells that helps the cell to maintain its shape. Smooth endoplasmic reticulum is involved in lipid synthesis. DNA is the genetic code molecules in the nucleus. RNA is involved in protein synthesis.
Example Question #636 : Cellular Biology
Which of the following is true regarding active transport?
The cell uses energy and protein pumps to move molecules across the membrane.
Osmosis occurs across the lipid bilayer.
The cell does not use energy and diffusion occurs.
The cell uses energy to bond molecules to the phosphate heads.
The cell uses energy and protein pumps to move molecules across the membrane.
In active transport, the cell uses energy (ATP) through the protein pumps to move molecules across the membrane. This process does not involve osmosis, which is a form of passive transport.