All MCAT Biology Resources
Example Questions
Example Question #1 : Connective Tissue Types And Properties
What are the four types of tissue?
Sensory, connective, nervous, dermal
Cardiac, connective, sensory, epithelial
Muscular, dermal, gastric, epithelial
Muscular, connective, nervous, epithelial
Muscular, cardiac, nervous, sensory
Muscular, connective, nervous, epithelial
The four types of tissue are muscular, connective, nervous, and epithelial.
Muscular tissue encompasses skeletal, cardiac, and smooth muscle. Nervous tissue creates the central and peripheral nervous systems (CNS, PNS) and consists of all neurons and glial cells. Epithelial tissue makes up "borders" and lines most organs. Connective tissue generally fills spaces and provides the suspensory matrices for the body, such as bone, fat, blood, and cartilage.
Example Question #781 : Systems Biology And Tissue Types
Which of the following is an example of an immovable joint?
Sacrailium
Phalanges
Tarsal joints
Pubic symphysis
Skull sutures
Skull sutures
Immovable joints are fused shortly after birth, so that they are no longer functional for articulation. The bones of the skull remain open, joined with strips of cartilage, until an infant has passed through the birth canal. They stay open for a short period, giving the baby's brain room to grow. After the brain has finished its major growth stages, the bones of the skull knit together, forming a protective barrier.
Example Question #792 : Biology
Tendons connect which two structures?
Joint and bone
Muscle and muscle
Bone and bone
Muscle and bone
Fat and fascia
Muscle and bone
Tendons connect muscles to bones, allowing for the muscle contraction to affect the bone and result in articulation. Tendons are essential to provide articulation and leverage points to for motion and locomotion.
Example Question #782 : Systems Biology And Tissue Types
Cartilage repair is slower than that of other connective tissues because __________.
chondrocytes are supplied by diffusion
chondrocytes have a larger surface area than cells of other connective tissues
chondrocytes produce a large amount of collagen
cartilage contains a higher denisty of blood vessels than other connective tissue
chondrocytes are supplied by diffusion
Cartilage does not contain blood vessels. Chondrocytes, the specialized cells of cartilage, are supplied by diffusion, which slows growth and repair. While they do produce collagen, this is not the direct reason for the relatively slow growth of cartilage.
Example Question #21 : Connective Tissue And Epithelium
Passage:
In a fictional universe, a new life form is discovered that appears to have a number of similarities to humans. Since its discovery by humans, it has been studied with x-ray imaging, magnetic resonance imaging (MRI), computed tomography imaging (CT), as well as with blood chemistries and laboratory studies. Based upon such analyses, scientists have found that both structurally and functionally, this fictional species, called Lorempis marengis, is highly similar to humans. It has structures that appear similar to lungs that are active during respiration. It has a structure that is highly active at all times, especially so in different parts during different activities (similar to the human brain). It also appears to have a digestive tract with a mouth, esophagus, stomach, small intestine, large intestine, and anus that is assumed to carry out the same functions at the cellular level as the parts of the human digestive tract. Scientists are now hoping to continue studying the organism at the cellular level to confirm their assumption that the cellular functions are indeed similar to those of human tissues.
If we assume that the muscle types and cells present in Lorempis marengis are the same, structurally and functionally, as those found in humans, which of the following muscle types best describes the type of muscle cell that lines the walls of most blood vessels?
Smooth muscle
Striated muscle
Skeletal muscle
Biceps muscle
Cardiac muscle
Smooth muscle
The type of muscle that lines the walls of most blood vessels in the human body is smooth muscle. We are told to make the assumption that the muscle types and cells present in Lorempis marengis are the same, structurally and functionally, as those found in humans. Therefore, the type of muscle that lines the walls of most blood vessels in Lorempis marengis is also smooth muscle. Blood vessels contain a specific subtype of smooth muscle, called vascular smooth muscle, that helps to regulate the distribution of blood volume throughout the entire body by either appropriately contracting or relaxing to restrict or increase blood flow to various parts of the body to best meet bodily needs (typically oxygen delivery).
Skeletal muscle cells, also known as striated muscles, are the type of muscle cells that make up the larger, weight-bearing muscles of the body. These are not the type of muscle cells that are found within the walls of blood vessels. The biceps muscles are the muscles responsible for flexion of the forearm at the elbow. They are not a type of muscle cell, per se, and they are made up of skeletal muscle cells.
Cardiac muscle cells are the type of muscle cells that make up the myocardium, or muscle cells of the heart. These are not the type of muscle cells that are found within the walls of blood vessels.
Example Question #1 : Circulatory And Respiratory Systems
Gas exchange in the lungs is located in the __________.
larynx
alveoli
epiglottis
pleural membrane
bronchioles
alveoli
Bronchioles end is clusters of small air sacs, the alveoli, where gas exchange occurs. Gases diffuse through the walls of the alveoli into the capillaries.
Example Question #2 : Respiratory System
Among the most important pH buffer systems in humans is the bicarbonate buffer, which keeps the blood at a remarkably precise 7.42 pH. The bicarbonate buffer system uses a series of important compounds and enzymes to make the system function. Figure 1 depicts the key reactions that take place.
The activity of this buffer system is mainly controlled by the renal and respiratory systems. The renal system excretes bicarbonate in the urine, while the respiratory system “blows off” carbon dioxide as needed. By balancing these two systems as needed, blood pH is maintained in such a narrow range.
When carbon dioxide is removed by the lungs, which of the following describes an accurate change in the system?
The pH of the blood goes down
The equilibrium shifts toward carbonic acid
Bicarbonate builds up in the blood
The pKa of carbonate goes down
The equilibrium shifts away from carbonic acid
The equilibrium shifts away from carbonic acid
As CO2 is blown off by the lungs, the equilibrium is shifted away from carbonic acid via Le Chatelier's principle. The system is attempting to recapture the lost carbon dioxide by producing more, thus depleting the volume of free carbonic anhydrase. Ultimately, the same principle will shift the equilibrium away from bicarbonate.
Example Question #1 : Respiratory System
Among the most important pH buffer systems in humans is the bicarbonate buffer, which keeps the blood at a remarkably precise 7.42 pH. The bicarbonate buffer system uses a series of important compounds and enzymes to make the system function. Figure 1 depicts the key reactions that take place.
The activity of this buffer system is mainly controlled by the renal and respiratory systems. The renal system excretes bicarbonate in the urine, while the respiratory system “blows off” carbon dioxide as needed. By balancing these two systems as needed, blood pH is maintained in such a narrow range.
A patient undergoes a procedure in a hospital, and begins to reabsorb large quantities of bicarbonate from the kidneys. In the above reaction __________.
the equilibrium is shifted toward bicarbonate
CO2 production will decrease, while carbonic acid concentration builds up
the equilibrium is shifted toward CO2
CO2 quickly builds up
carbonic anhydrase prevents a shift in equilibrium
the equilibrium is shifted toward CO2
Via Le Chatelier's principle, the equilibrium is quickly shifted toward CO2, however, as the passage details, CO2 does not build up. Instead, it is blown off via the respiratory system.
Example Question #1 : Respiratory System
In mammals, what muscles are involved in inhalation?
External intercostals only
Internal intercostals and diaphragm
External intercostals and internal intercostals
External intercostals and diaphragm
Diaphragm only
External intercostals and diaphragm
During inhalation, the external intercostal muscles and diaphragm both contract to help expand the thoracic cavity and draw in air. The internal intercostal muscles are involved in exhalation, and compress the thoracic cavity during contraction.
Example Question #2 : Respiratory System
Which of the following is not one of the four processes that comprise external respiration?
Exchange of oxygen and carbon dioxide between the blood and tissues via diffusion
Use of oxygen within the mitochondria to generate ATP via oxidative phosphorlyation
Transporation of oxygen and carbon dioxide between the lungs and body tissues via the blood
Exchange of oxygen and carbon dioxide between lung air spaces and the blood via diffusion
Pulmonary ventilation
Use of oxygen within the mitochondria to generate ATP via oxidative phosphorlyation
The use of oxygen within the mitochondria to generate ATP via oxidative phosphorylation is a part of internal, or cellular, respiration.
The other four processes listed are all parts of external respiration, consisting of the mechanisms used to transport gases between the atmosphere and the body.