15. Bootcamp Qs Flashcards
All of the following statements are part of modern cell theory EXCEPT one. Which one is the EXCEPTION?
A. An organism’s activity is dependent on the activity of its independent cells.
B. Metabolism and biochemistry occur within cells.
C. Hereditary information is stored in cells and is shared between cells during cell division.
D. All cells contain a nucleus for the storage of genetic material.
E. All cells in organisms of similar species have similar chemical compositions.
D. All cells contain a nucleus for the storage of genetic material.
Prokaryotic cells do not have a centralized nucleus and do not have many of the other cell organelles that eukaryotic cells have with the exception of ribosomes
Turner Syndrome
Turner syndrome is an aneuploidy (specifically a monosomy) that is the result of a missing X chromosome due to nondisjunction in gamete formation during meiosis. Rather than having the expected sex genotype of XX, a female with Turner Syndrome would be XO, indicating the absence of an X chromosome.
A scientist wants to detach a peripheral membrane protein from the exterior of a cell membrane. Which is the best method to do so?
A. Change the salt concentrations.
B. Perform a light centrifuge.
C. Add a detergent.
D. Change the temperature of the solution.
E. Run a small current through the solution.
A. Change the salt concentrations.
Peripheral membrane proteins are held in place by electrostatic interactions and hydrogen bonding. They are generally hydrophilic. Changing the salt concentration (a “salt wash”) or the pH would disrupt both of these types of bonds and release the peripheral membrane protein from the cell membrane. Adding a detergent is a method used to extract integral proteins because they are more hydrophobic in nature. The hydrophobic detergent will destroy the membrane and expose the hydrophobic integral protein. Changing the temperature will denature the protein. Running a current through the cell isn’t a common or viable method. Running a small current through the solution – a technique known as electroporation – is used to create temporary holes in the plasma membrane. This does not detach peripheral membrane proteins from the external surface; therefore the answer choice is incorrect. Electroporation is often used on bacterial cells to introduce foreign DNA.
Facilitated Diffusion
- passive transport of particles down their conc. gradient.
- ex. quaporins, a channel protein that allows for water to flow more rapidly than simple diffusion
A toxin is released into the body that promotes the degeneration of microfilaments. Which of these structures is most likely to be directly affected?
A. Spindle fibers radiating from centrioles B. Lysosomes C. The extracellular matrix D. Chromosomes E. Muscle cells
E. Muscle cells
Our muscles are made of long chains of cytoskeleton comprised of two filaments – actin and myosin. Of these, actin is a microfilament, while myosin is a motor protein. If actin degenerates, then our muscles would not contract, thus, our answer is E. The spindle fibers radiating from the centrioles are microtubules. A lysosome is an organelle that is involved in phagocytosis. The extracellular matrix consists of protein fibers and glycosaminoglycans. Chromosomes are made of nucleic acids. Microfilaments are primarily made of actin filaments and are primarily involved in motility. Substantial amounts can be found in skeletal muscle (where microfilaments are a key component of the sliding filament model of contraction), the pseudopod of amoeba (used for cell motility), and the cleavage furrow during animal cell division (actin and myosin microfilaments shorten and pull the plasma membrane towards the center of the cell); therefore the answer choice is correct.
Competitive Inhibition
A competitive inhibitor is one that binds directly to the active site and prevents the reactant from binding. Competitive inhibition results in a higher Km (the Michaelis constant that represents the substrate concentration at which the rate is half of Vmax – the higher the Km, the lower the binding affinity between enzyme and substrate) but since competitive inhibition can be overcome by increasing the substrate concentration, there is no change in Vmax (the maximum reaction rate).
What is the name of the structure that allows bacteria to stick to a surface?
A. Flagella B. Clathrin C. Nucleoid region D. Teichoic acids E. Pili
E. Pili
Pili are small short “hairs” called fimbriae on the surface of bacteria that can be used in the exchange of genetic material between bacteria and in cell adhesion. Bacterial flagellum is a long “tail” made of flagellin that provides locomotion to a bacterial cell. In eukaryotes, flagellum is made of microtubules. Clathrin is a receptor protein on the surface of a cell. A nucleoid region is where the DNA exists in a bacterial cell as it does not have a nucleus. Teichoic acids are found only on gram-positive bacteria and help keep the cell wall rigid. Clathrin is a protein that coats vesicles and plays a critical role in their formation, as well as their incorporation into the cell membrane during exocytosis and endocytosis.
Flagella in Eukaryotes vs. Prokaryotes
- eukaryotes: microtubules
- prokaryotes: flagellin
Which of the following best defines a notochord?
A. A component that eventually develops into the spinal cord.
B. A length of cartilage extending along the body, which will become part of the spinal discs.
C. That which will become the pharynx, gills, or other feeding system in the animal.
D. A muscular tail extending behind the anus.
E. A groove located in the underside of the pharynx that produces mucus in filter-feeding species.
B. A length of cartilage extending along the body, which will become part of the spinal discs.
The notochord is the feature that will eventually develop into a part of the spinal discs. The spinal cord begins as the dorsal neural tube. Pharyngeal slits are present in all chordates at some point during their development. For fish they will become gills, in other animals it will evolve into the pharynx, and in urochordates they are part of the filter-feeding system. The muscular tail that extends behind the anus is known at the post-anal tail. The endostyle is what produces mucus for filter feeders.
Four main features shared by chordates during development
- Notochord
- Dorsal hollow nerve cord
- Pharyngeal gill slits
- Muscular post-anal tail
All of the following phyla have a complete digestive system EXCEPT for one. Which of the following is the EXCEPTION?
A. Nematoda B. Annelida C. Mollusca D. Echinodermata E. Platyhelminthes
E. Platyhelminthes
Platyhelminthes do not have a complete digestive system, so the answer choice is correct (it is important to know that Cnidaria also lack a complete digestive system – both Cnidaria and Platyhelminthes instead have a gastrovascular cavity in which two way digestion takes place, rather than the one way digestion through an alimentary canal seen in other classes with digestive systems). Platyhelminthes are triploblasts with bilateral symmetry, and are acoelomate. Examples include flatworms, tapeworms, and flukes.
There are many shared traits between fungi and the other four kingdoms. Of the five statements below, which one is unique to fungi?
A. Some fungi are bioluminescent.
B. Fungi have a cell wall, vacuoles, use sexual and asexual means of reproduction and produce spores.
C. Fungi undergo an alternation of generations.
D. Fungi cell walls are made of glucans and chitin.
E. Fungi are heterotrophic, lack chloroplasts and are reliant on organic compounds for energy sources.
D. Fungi cell walls are made of glucans and chitin.
Plants have cell walls, vacuoles, and use different means of reproduction to produce spores. Animals are heterotrophic, lack chloroplasts, and are reliant on organic compounds for energy sources. Plant cell walls are known to contain glucans, and some animal exoskeletons contain chitin. However, fungi are the only organism known to use both, making this feature unique to fungi only.
What type of immunity is defined by the transfer of antibodies from one person to another, most commonly illustrated when a woman breastfeeds her newborn infant?
A. Active immunity B. Passive immunity C. Natural immunity D. Artificial immunity E. Permanent immunity
B. Passive Immunity
Passive immunity, although not a permanent form of immunity, occurs when one organism can pass along their antibodies to another organism to prevent infection. With newborn infants, they lack the immunity needed to combat most illnesses, however a nursing woman can pass along her antibodies through the colostrum, the precursor to breast milk. Active immunity is brought about when an organism is infected or exposed to a virus/bacterium that then causes an internal initiation of the immune system. With this type of immunity, the organism makes its own memory cells to be ready for a later infection.
Natural immunity refers to when an immune response is generated by natural means (as opposed to an artificial method, such as the use of a vaccine).
Artificial immunity refers to when an immune response is generated by artificial means, such as in vaccination where antigenic material is intentionally introduced to cause an immune response.
Oligodendrocytes are best associated with:
A. Beta cells of the pancreas B. G cells of the stomach C. Nerves in the peripheral nervous system D. White matter of the brain E. Spermatogonia of the testes
D. White matter of the brain
Oligodendrocytes are responsible for laying down the myelin sheath surrounding neurons in the central nervous system, so choices [A], [B] and [E] can be eliminated. Remember, the central nervous system includes the brain and the spinal cord. Schwann cells perform the same function in the peripheral nervous system (PNS).
Myelination insulates the neurons (like the plastic around an electrical wire) and allows the neurons to transmit electrical impulses more quickly and efficiently. Without myelination, your neurons will not be able to properly communicate together, resulting in a variety of diseases, such as multiple sclerosis.
The main extracellular buffer system in humans consists of:
A. amphipathic proteins B. phosphate C. sulfate D. bicarbonate E. histamines
D. Bicarbonate
The main extracellular buffer is bicarbonate. This is how CO2 is transported throughout the body. The body uses pH sensors to determine how much we have to breathe. If we are exercising vigorously then our cells will produce large amounts of CO2, which will lower our extracellular pH (make it more acidic due to the CO2), which will make us breathe more to expel the excess CO2.
Phosphate and other proteins are used as the main intracellular buffer inside cells.
All of the following hormones are derived from cholesterol EXCEPT one. Which one is the EXCEPTION?
A. Aldosterone B. Cortisol C. Epinephrine D. Testosterone E. Progesterone
C. Epinephrine
Cholesterol is characterized by 4 rings and is the precursor to many steroid hormones. Aldosterone, testosterone, and progesterone all sound very similar, and these are all steroids that are derived from cholesterol. Cortisol is another steroid that is released by the adrenal cortex and involved in stress adaptation.
Which of the following is a method marine fish use to maintain homeostasis?
A. Swim towards freshwater. B. Rarely drink water. C. Absorb salts through gills. D. Constantly urinate. E. Constantly drink water.
E. Constantly drink water.
A marine fish is hypoosmostic to its environment, meaning that it is less salty than the concentrated saltwater surrounding it. Therefore, it will constantly lose water to the environment. To make up for this, the marine fish must constantly drink water. It also rarely urinates to not waste any water, and it secretes the salts it acquires from constantly drinking.
In contrast, freshwater fish are hyperosmotic, or saltier than their environment. Therefore, water will constantly flow into the fish. The fish must constantly urinate to get rid of the excess water. It also rarely drinks, and absorbs salt through its gills to maintain homeostasis.
SUMMARY
Fish in freshwater environments:
Are hyperosmotic relative to their environment
Drink very little water
Salt enters the gills via active transport
Produce large volume of urine
In contrast, fish in saltwater environments (i.e. marine fish):
Are hypoosmotic relative to their environment
Constantly drink
Salt leaves the gills via active transport
Produce low volume of urine
In mammals, which of the following structures aides the embryo in gas exchange and the disposal of liquid waste?
A. Yolk B. Amnion C. Allantois D. Chorionic Villi E. Yolk Sac
C. Allantois
In mammals, the chorionic villi eventually form the placenta, but the villi are finger-like sections that burrow into the wall of the uterus near the mother’s blood vessels. The allantois disposes of wastes, and forms part of the umbilical cord to carry waste away from the embryo and towards the mother’s blood vessels. The amnion is a thin sac that surrounds the embryo and produces amniotic fluid to provide cushion for the growing embryo. Mammals do not have yolk, and the yolk sac contains only fluid to cushion the growing embryo and has blood vessels in it that give rise to the vascular system of the embryo. In birds, the yolk sac serves to nourish the embryo throughout its development.
Nondisjunction occurring during meiosis II, followed by fertilization, would result in a zygote with which of the following chromosomal descriptions?
A. Aneuploid
B. Haploid
C. Diploid
D. Tetraploid
A. Aneuploid
In meiosis II, the individual chromosomes line up on the metaphase plate and are separated by spindle fibers. Each resulting cell should have one of each chromosome. When non-disjunction occurs during meiosis II the chromosome is not separated and instead one of the resulting cells produced will have two copies of the same chromosome and one cell will be missing a chromosome. This is referred to as aneuploidy, or the occurrence of having an abnormal amount of chromosomes, either more or less than 23. A normally dividing cell will begin meiosis as a diploid cell, with two copies of each chromosome, equaling 46 chromosomes (23 pairs) total. After meiosis I, the cells produced are haploid, containing one copy of each chromosome, totaling 23 chromosomes total.
Which of the following are best characterized by brackish water?
A. A river emptying into an inland lake. B. A mangrove leading to an estuary. C. A stream in a tropical forest. D. A freshwater marsh and lake. E. Seawater washing onto a beach.
B. A mangrove leading to an estuary.
Brackish water means a mix between salt and fresh water, which would be found in an estuary. An estuary is a specific area where freshwater meets seawater. A mangrove swamp often grows near an estuary and is characterized by a mix of salt and freshwater. Some marshes can be brackish, but D specifically stated that this marsh was freshwater, and thus not characterized by brackish water.
A species of desert plant secretes a chemical into the surrounding soil that kills seeds from any other species of plant that attempts to germinate in that area. What is this an example of?
A. Commensalism B. Allelopathy C. Exploitation competition D. Apparent competition E. Intraspecific competition
B. Allelopathy
Allelopathy is type of interference competition, where the establishment of other individuals who would compete for a mutual resource is prevented, in this case using a toxic chemical. Intraspecific competition (E) occurs when competition occurs within the same species; in this case the plant is competing with all the other species of plants in the area.
In commensalism, a form of symbiosis, one of the two organisms benefits while the other remains unaffected.
Exploitation competition is a type of competition that occurs indirectly through depletion of a common resource. For example, lions and cheetahs face exploitation competition in Africa as both hunt for a common resource: the gazelle. If cheetahs were more successful and ate all the gazelles, lions would suffer from depletion of the food resource.
Apparent competition is a type of competition that occurs between two species preyed upon by the same predator. For example, say a species of spider and a species of beetle are both hunted by owls and the amount of spiders suddenly increased. This would lead to survival of more owls (due to the increased food resource of spiders), which would in turn hunt more of the beetles, ultimately decreasing their overall number.
Intraspecific competition is a type of competition that occurs between members of the same species.
Which biome is characterized as the largest biome on Earth with long harsh, snowy winters, short rainy and humid summers and with a landscape dominated by conifers?
A. Deciduous forest B. Savanna C. Tundra D. Taiga E. Chaparra
D. Taiga
Deciduous forests do have winters, but they are not characterized as harsh or very snowy and this biome is known for having 4 distinct seasons each year. The savanna biome has small grasses, small shrubs, scattered trees, and have both dry and rainy seasons. The tundra biomes are best defined as regions that have short growing season, cold temperatures all year round and have a layer of permafrost over the soil. The taiga biome has long, cold winters and very short rainy seasons. Taiga does have vegetation with most of the tree covering being provided by conifers like spruce, fir and pine trees. Tropical deserts are characterized as having extremely high temperatures with sporadic rainfall.
What is the original source of energy used to drive the light independent reactions of photosynthesis?
A. Substrate level phosphorylation B. The breakdown of glucose C. Photolysis of water to release electrons D. ATP produced by mitochondria E. Photons absorbed by chlorophyll
E. Photons absorbed by chlorophyll
When light (photons) is present, the light-absorbing pigments absorb energy. This energy excites electrons, which become unstable and re-emit the absorbed energy, which is then absorbed and re-emitted by electrons of nearby pigment molecules until this energy is absorbed by chlorophyll molecules. This process allows for noncyclic photophosphorylation to occur, which in turn provides the ATP molecules used for energy in the light independent reactions of photosynthesis
If 2n=8, how many chromosomes are present during anaphase?
A. 2 B. 4 C. 8 D. 16 E. 32
D. 16
An animal cell was lysed, placed in a test tube, and centrifuged. Which organelle would pellet from the centrifuge first?
A. Ribosome B. Lysosome C. Mitochondria D. Golgi complex E. Nucleus
E. Nucleus
- The nucleus is the largest and most dense organelle in the cell and will pellet first.
- ribosomes would be expected to pellet out last due to their small density and size
- Lysosome would be expected to pellet out after the nucleus, but before the smaller and less dense ribosomes.
A scientist wishes to create bacterial colonies on an agar plate for observation of growth. Unfortunately, directly adding bacteria from the original culture results in too many bacterial colonies to count. In order to create a solution of proper bacterial concentration for observation, the scientist performs a three-step 1:100 serial dilution of the original bacterial culture. What is the dilution factor of the final solution?
A. 10^-9 B. 10^-3 C. 3.0 D. 10^3 E. 10^6
E. 10^6
- In this problem, the scientist performed a three-step 1:100 dilution, meaning they diluted the original concentration first to 10^-2, then to 10^-4, and finally to 10^-6. The question asks for the dilution factor, which is the final volume divided by the original volume (or the inverse of the concentration)
What is the purpose of SDS (sodium dodecyl sulfate) in protein analysis?
A. Denature non-covalent bonds in a protein
B. Decrease the surface area of the protein
C. Impart a positive charge on the protein
D. To cut the protein at specific sequences
E. Dye the proteins to track their run
A. Denature non-covalent bonds in a protein
- Sodium dodecyl sulfate is a very strong anionic detergent that is used in gel electrophoresis to separate proteins based on their electrophoretic mobility (a function of the length of a protein and its charge). SDS is used to denature and linearize proteins and to impart a negative charge to the proteins. You could deduce it would impart a negative charge and not a positive one because sulfate is very negative and anionic. With this method, only the protein’s size and charge will be compared. Generally, all gel electrophoresis will denature a protein to compare its size
- SDS (sodium dodecyl sulfate) has three primary effects on protein:
Denatures the protein
Linearizes the protein
Adds negative charge to the protein
The SDS-PAGE (polyacrylamide gel electrophoresis) is used to separate proteins on the basis of size (molecular weight). Smaller proteins will travel further than large proteins from the negative cathode to the positive anode.
All of the following directly use an electrochemical gradient EXCEPT one. Which one is the EXCEPTION?
A. Flagella rotation B. Mitochondria C. Chloroplasts D. Aquaporins E. Neurons
D. Aquaporins
- Aquaporins are protein structures in the membrane that help water passively flow into or out of the cell, a process known as facilitated diffusion.
In the alternation of generations, what do spores directly give rise to?
A. Gametes B. Zygotes C. Gametophyte D. Sporophyte E. Seeds
C. Gametophyte
Which of the following lack a true coelom?
A. Flatworms B. Annelids C. Echinoderms D. Chordates E. Mollusks
A. Flatworms
- A coelom is a cavity lined by an epithelium derived from mesoderm. Mollusks have a reduced, but still true, coelom. A flatworm(also known as planarian) is an acoelomate because it does not have a coelom within its mesoderm layer.
- Acoelomate: flatworms
- Pseudocoelomate: roundworms
- True coelomate: molluscs, annelids, arthropods, echinoderms, chordates
Bacteria Appearance
Diplo-: pairs Strep-: chain Staph-: grape-like clusters -coccus: spherical -bacillus: rod-like Spirilla/spirochetes: spirals
Digestive Enzyme Summary
Mouth: salivary amylase (carbohydrates)
Stomach: Pepsin (proteins)
Pancreas: pancreatic amylase (carbohydrates), pancreatic trypsin and chymotrypsin (proteins), carboxypeptidase (proteins), nucleases (DNA, RNA), lipase (fats) [Note: these digestive enzymes are secreted by the pancreas but carry out their function in the small intestine]
Small Intestine: Disaccharidases (carbohydrates), dipeptidases and aminopeptidases (proteins), nucleotidases (nucleotides), nucleosidases (nucleosides)
Anterior Pituitary Hormones
- FSH Follicle stimulating hormone Regulate development, growth, and reproduction. FSH helps develop a primary follicle. It acts synergistically with LH.
- LH Luteinizing Hormone Regulate development, growth, and reproduction. Acute increase in LH triggers ovulation and develops corpus luteum. In males it stimulates Leydig cells to produce testosterone. It acts synergistically with FSH.
- ACTH Adrenocorticotropic Hormone Stimulates adrenal cortex
- TSH Thyroid-stimulating hormone Stimulates the thyroid
- HGH Human growth hormone Regulates protein synthesis and cell division
- Prolactin Prolactin Production of milk in mammary glands
An increase in calcitonin would lead to which of the following?
A. Increase calcium concentration in blood
B. Decrease calcium reabsorption in bones
C. Stimulate osteoblast activity
D. Stimulate osteoclast activity
E. An increase in muscle contractions
C. Stimulate osteoblast activity
- Two hormones regulate calcium levels in blood: calcitonin (produced by the thyroid), and parathyroid hormone (produced by the parathyroid). Calcitonin serves to lower calcium levels in blood. It does this by stimulating osteoblast activity, which builds up bone, which requires using calcium in the blood. Parathyroid hormone is the opposite, if calcium levels are too low in the blood, it will stimulate osteoclast activity to release calcium from the bones to the blood.
Which of the following components of the immune system responds to specific antigens?
A. B cells B. Interferons C. Phagocytes D. Cilia E. Lysozyme
A. B cells
- There are two parts to the immune system: specific and nonspecific defense. Specific defense responds to antigens, such as the toxin from an insect sting, or a molecule on the plasma membrane of a pathogen. Nonspecific defense is not specialized for a particular pathogen; it defends against all pathogens in general. Examples of nonspecific defenses include: skin, interferons, phagocytes, cilia, and lysozyme. Interferons are molecules secreted by cells invaded by viruses that stimulate other cells to help defend against viruses. Phagocytes are white blood cells that engulf pathogens. Cilia line the lungs and help sweep pathogens out of the lungs. Lysozyme is a protein that breaks down cell walls in bacteria.
- The distinguishing characteristic of B cells is that they all possess a B cell receptor (BCR), which binds to specific antigens, making this answer correct. Formed in the bone marrow, B cells are important because they can differentiate into memory B cells, which can produce antibodies for pathogens that have already been encountered.
After ejaculation, what process must sperm undergo before they are competent to fertilize an oocyte?
A. Acrosome reaction B. Oogenesis C. Metamorphosis D. Sperm meiosis E. Capacitation
E. Capacitation
- Capacitation refers to the increased flagella motility and destabilization of the acrosomal membrane seen in ejaculated sperm. Capacitation is a necessary step for a sperm to be able to penetrate an oocyte’s zona pellucida and fertilize the egg, so this answer is correct.
Three Germ Layers
- Ectoderm: Epidermis of skin, hair, nails, nervous system, lens of eye, enamel of teeth
- Mesoderm: Dermis of skin, muscle, skeleton, circulatory system, gonads, kidneys, respiratory tracts, notochord
- Endoderm: Lining of digestive and layer of respiratory tracts, liver, pancreas
Sickle-cell disease is caused by a defective hemoglobin gene, resulting in several phenotypic outcomes. Which of the following describes sickle-cell disease?
A. Dominant B. Polygenic inheritance C. Pleiotropy D. Epistasis E. Linked genes
C. Pleiotropy
- Pleiotropy occurs when a single gene has multiple phenotypic outcomes. In sickle-cell disease, a single mutation produces abnormal hemoglobin molecules. This results in damage to many organs and also results in several disorders. In contrast, polygenic inheritance is when many genes contribute to one phenotypic outcome. A great example is the height of humans, which is controlled by many genes and results in one phenotype. Epistasis occurs when one gene affects the expression of the second gene.
- Epistasis describes when one gene affects the phenotypic expression of a second gene
Which part of the brain monitors the body’s temperature?
A. Hypothalamus
B. Pons
C. Medulla
D. Cerebral cortex
E. Cerebellum
A. Hypothalamus
The hypothalamus controls the body’s temperature, hunger, thirst, sleep, and circadian cycles. One of its most important functions is that it links the nervous system to the endocrine system through the pituitary gland. The pons relays signals from the forebrain to the cerebellum. The medulla controls autonomic functions, such as respiration, digestion, and the pumping of the heart. The cerebral cortex is a complex portion of the brain that is involved in higher-level thinking and sensory perception. Lastly, the cerebellum is involved in motor control, such as balance and coordination.
The diastole phase of circulation is associated with the:
A. contraction of the ventricles.
B. closing of the AV valves.
C. opening of the semilunar valves.
D. closing of semilunar valves.
E. relaxation of the atriums.
D. closing of semilunar valves.
When the heart contracts, the ventricles force blood through the semilunar valves and into our arteries. Also during this time, the AV valves are shut to prevent the blood from being forced back into the atriums. When the ventricles relax, the semilunar valves are shut to prevent backflow from the blood they just forced into the arteries, and the AV valves are reopened; this is called the diastole phase. The opening and closing of the AV valves and semilunar valves causes the “lub-dup” sounds in the heart.
The ventricles contract during the systole phase of circulation, not the diastole phase; therefore the answer choice is incorrect. When the ventricles contract, the AV valves snap shut to prevent backflow of blood – this is responsible for the “lub” part of the “lub dub” sound in heart beats.
When the ventricles contract, the AV valves snap shut to prevent backflow. The contraction of the ventricles is associated with the systole phase of circulation, not the diastole phase
The aortic and pulmonary semilunar valves snap shut when the ventricles relax, to prevent backflow from the pulmonary artery and aorta. The relaxation of the ventricles is associated with the diastole phase of circulation, so the answer choice is correct. The closing of the semilunar valves is responsible for the “dub” part of the “lub dub” sound in heart beats.
All of the following can be found in the filtrate from the Bowman’s capsule EXCEPT for one. Which one is the exception?
A. Glucose
B. Salts
C. Vitamins
D. Nitrogen wastes
E. Proteins
E. Proteins
In the kidney system, blood enters from an afferent arteriole into the glomerulus, where pressure forces water and solutes through the capillary walls into the Bowman’s capsule, like a sieve. Small particles can be pushed through the capillary walls, but red blood cells and proteins cannot pass through and remain in the blood. The filtrate in the Bowman’s capsule will then travel through the nephron, where the majority of salts, water, and glucose will be reabsorbed.
Proteins are not able to filter through the fenestrations in the glomerulus into the Bowman’s capsule, so the answer choice is correct. The Bowman’s capsule and the glomerulus are both components of the renal corpuscle, which together with the renal tubule forms a nephron. Hydrostatic pressures force blood plasma through the fenestrations of the glomerulus – these fenestrations screen out blood cells and large proteins to prevent them from entering the Bowman’s capsule. Additionally, podocytes (cells in the Bowman’s capsule) further filter blood to prevent large molecules like protein from passing through, but allow smaller ones (including sugar, water, salts, vitamin, and nitrogen wastes).
Which of the following pairs of structures target the same organ with different hormones?
A. Pancreas and thyroid
B. Testes and posterior pituitary
C. Posterior pituitary and adrenal cortex
D. Adrenal medulla and parathyroid
E. Adrenal cortex and thyroid
C. Posterior pituitary and adrenal cortex
The posterior pituitary releases ADH, which allows the kidneys to reabsorb more water. The adrenal cortex releases mineralocorticoids, such as aldosterone, which affects the kidney to increase salt reabsorption (which in turn increases water absorption as well due to changes in osmolarity).
The pancreas releases glucagon (increase blood glucose) from alpha cells and insulin (decrease blood glucose) from beta cells. The thyroid controls general metabolism and releases calcitonin, which lowers blood calcium. The parathyroid releases PTH (parathyroid hormone), which increases blood calcium. The anterior pituitary releases FSH, LH, ACTH, TSH, prolactin, and growth hormone. The testes produce testosterone.
The testes produce testosterone (that affect the testes themselves and have general effects on secondary sexual characteristics). The posterior pituitary stores antidiuretic hormone (ADH) and oxytocin produced by the hypothalamus; ADH targets the kidney, while oxytocin targets the mammary glands and uterus. These structures do not produce hormones that target the same organ
The posterior pituitary stores antidiuretic hormone (ADH) and oxytocin produced by the hypothalamus; ADH targets the kidney, while oxytocin targets the mammary glands and uterus. The adrenal cortex produces glucocorticoids (such as cortisol) that affect the body on a general level to increase blood glucose, and mineralocorticoids (such as aldosterone) that target the kidney. Since the posterior pituitary produces ADH that targets the kidney, and the adrenal cortex produces a different hormone (aldosterone) that targets the kidney, the answer choice is correct. ADH increases reabsorption of water, while aldosterone increases reabsorption of Na+ and excretion of K+.
The adrenal cortex produces glucocorticoids (such as cortisol) that affect the body on a general level to increase blood glucose, and mineralocorticoids (such as aldosterone) that target the kidney. The thyroid produces thyroxine (T4) and triiodothyronine (T3) which target the general metabolic rate of the body, and calcitonin which targets the bones.
The ingestion of which of the following would stimulate the release of cholecystokinin?
A. Carbohydrates
B. Fats
C. Nucleic acids
D. Cellulose
E. Inorganic compounds
B. Fats
Cholecystokinin is a hormone produced by the small intestine in response to fats. It stimulates the gallbladder to release bile, which helps in the emulsification of fats, and stimulates the pancreas to release lipases. Gastrin is produced once the nervous system sees or smells food, which stimulates the stomach to produce gastric juices. Secretin is produced in the small intestine and stimulates the pancreas to produce bicarbonate to neutralize the acidity of the chyme.
Cellulose does not stimulate the release of cholecystokinin; therefore the answer choice is incorrect. Cellulose cannot be broken down by the human digestive system, as we lack the necessary enzymes to break the beta-glucose linkages found in its polysaccharide structure. In ruminant digestive systems, cellulose is broken down by bacteria present.
