PCAT Biology

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PCAT Biology
2010-08-03 14:16:01
PCAT Biology

PCAT Biology
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  1. What type of excretory system do annelids employ?
    Excrete urea through nephridia in skin.
  2. What type of excretory system do arthropods employ?
    Produce uric acid in the Malpighian tubules and eliminate it through rectum.
  3. (T/F) IN coelenterates, ammonia and CO2 diffuse directly into the environment.
  4. (T/F) In protozoans, ammonia and CO2 diffuse directly into the environment.
  5. What type of respiratory system do annelids employ?
    Gas exchange via diffusion through moist skin (e.g. worms)
  6. What type of respiratory system do arthropods employ?
    Gas is exchanged through respiratory tracheae which branch extensively throughout the body. Air enters and leaves the trachea via openings on the surface called spiracles (e.g grasshopper)
  7. What type of respiratory system do coelenterats emloy?
    Gas exchange via diffusion through individual cell membranes contacting aqueous environment.
  8. What type of respiratory system do protozoans employ?
    Gas exchange via diffusion through individual cell membranes contacting aqueous environment.
  9. What is a fixed action pattern?
    A complex, coordinated, innate behavioral respone to specific patterns of stimulation; the sign stimulus/releaser elicits the highly stereotyped behavior that must be completed once begun.
  10. (T/F) Imprinting can only take place during a brief critical period.
  11. In classical conditioning, in order to elicit the conditioned response from the conditioned stimulus, what mus be presented along with the conditioned stimulus during the conditioning period?
    In classical conditioning, the combination of presenting the conditioned stimulus along with the unconditioned stimulus (the bell along with the meat) during the conditioning period elicits the conditioned response (salivation) later on.
  12. (T/F) Operant conditioning may be used only to make an organism avoid a ceratin type of behavior.
    False. Operant conditioning may be utilized to make an organism repeat or avoid a certain type of behavior, depending on whether that behavior is associated with a reward or punishment, respectively.
  13. What happens during the light cycle?
    Light energy is used to produce ATP through photophosphorylation and photolysis (slitting water), while forming O2 and NADPH.
  14. What happens durings the dark (Calvin) cylce?
    ATP and NADPH formed during the light reaction are used to fix CO2 into organic material. Light is not required, but the dark cycle usual occurs during the day, when the light reaction provides ATP and NADPH.
  15. (T/F) Sugars may be synthesized once the light cycle has shut down?
    True. [The dark (Calvin) cycle can continue in the absence of light.]
  16. What molecule provides the reducing power needed during the synthesis of sugar?
  17. (T/F) Chemosynthetic bacteria do not rely on photosynthesis for survival.
  18. What are the three directly biological sources of CO2 in the environment?
    Respiration, photosynthesis, and the decomposition of plant and animal materials by bacteria of decay.
  19. Order the levels of biological organization from smallest to largest: Biosphere, Community, Organism, Population, Ecosystem.
    Organism, Population, Community, Ecosystem, Biosphere.
  20. What are the characteristics of the population growth curve that occurs most often in nature?
    The logistic growth curve is an S-shaped curve that plateaus at a value know as K (the carring capacity), the maximum number of organisms the environment can support as a result of the limited amount of resources.
  21. What is asexual reproduction?
    Any reproductive process that does not involve the fusion of gametes.
  22. (T/F) Binary fission (characteristic of prokaryotes) entails an equal division of cytoplasm as well as nuclear contents.
  23. (T/F) Budding entails an equal division of cytoplasm as well as nuclear contents.
    False. Budding is an asexual reproductive process characteristic of yeast in which there is an equal division of genetic material and an unequal division of cytoplasm. The daughter cell may pinch off and live independently, or remain connected and live as a part of the larger colony.
  24. What is parthenogenesis?
    Development of an egg in the absence of fertilization, resulting in a haploid organism; e.g. sometimes occurs in frogs.
  25. What are the five kingdoms of living organisms?
    Monera, Protista, Fungi, Plantae, and Animalia.
  26. What are the subdivisions used in classifying an organism within a given kingdom?
    Kingdom, Phylum, Subphylum, Class, Order, Family, Genus, Species
  27. What is the Founder effect?
    When a few individuals inhabit an isolated region, the smaller the sample size, the genetic composition of that region is less likely to represent the genetic composition of the larger population the isolated population is derived from. This type of genetic draft in an isolated group is known as Founder effect.
  28. (T/F) Convergent evolution is due to homology.
    False. Convergent evolution is due to analogy.
  29. Place the following objects in the order in which they exist in the energy pyramid, from the top to the bottom: Secondary consumers, Producers, Sunlight, Detrivores, Primary consumers.
    Sunlight, Producers, Primary consumers, Secondary consumers, Detrivores.
  30. What are omnivores?
    Omnivores are heterotrophs that consume both plants and animals.
  31. What role do animals have in the nitrogen cycle?
    The wastes and dead remains of plants and animals provide the ammonia used by nitrifying bacteria to produce nitrites and nitrogen dioxide and used by denitrifying bacteria to produce free nitrogen in the atmosphere.
  32. (T/F) Nitrogen fixation occurs in the stalks of leafy green vegetable plants.
    False. Bacteria on the roots of legumes are responsible for nitrogen fixation.
  33. What type of circulatory system do annelids employ?
    Closed, simple circulatory system.
  34. What type of circulatory system do arthropods employ?
    Open circulatory system.
  35. What type of circulatory system do coelenterates employ?
    Diffusion, cyclosis.
  36. What type of circulatory system do protozoans employ?
    Diffusion, cyclosis.
  37. During what stage of the cell cycle does DNA replicate?
    • DNA is replicated during the S,or synthesis phase. During the G1 phase, the cell synthesizes enzymes and structuralproteins needed for growth. During the G2 phase, the cell assembles the spindle apparatus.
    • During the M phase, mitosis (cell division) occurs.
  38. (T/F) In humans, most sex-linked genes are located on the Y chromosome.
    False, most sex-linked genes are on the X chromosome.
  39. What percentage of daughters will inherit their father's sex linked gene?
    100% of daughters will inherit their father's sex-linked gene.
  40. What percentage of sons will inherit their father's sex-linked gene?
    0% of sons will inherit their father's sex linked gene?
  41. What percentage of sons will inherit their mother's sex linked gene (assuming a heterozygous mother)?
    50% of sons will inherit their mother's sex linked gene.
  42. What type of nervous system do annelids employ?
    A primitive central nervous system with a brain composed of fused ganglia.
  43. What type of nervous system do arthropods employ?
    A nervous system similar to that of annelids, but with specialized sense organs.
  44. (T/F) Coelenterates employ a nerve net as their nervous system?
  45. What are the names of the male and female reproductive organs of a plant and their parts?
    A flower's male organ is know as the stamen, which consists of the filament, a long stalk-like segement, and the anther, a small sac at the top of the filament. A flower's female organ is known as the pistil, and consists of the stigma (the sticky surface that catches the pollen), style (the area the pollen tube grows down), and ovary (eventually forms the fruit and contains seeds called ovules).
  46. Where and what type of gametes are formed in male and female plants?
    Pollen is produces in the anther; the embryo sac (containing several nuclei, including two polar nuclei and the egg nucleus) forms in the ovules.
  47. How many N are the plant gametes, embryo, and endosperm?
    1N, 2N, 3N respectively.
  48. How is material exchanged between exchanged between the nucleus and the cytoplasm?
    The nuclear membrane contains nuclear pores that selectively allow for the exchange of materials.
  49. What is a histone?
    A histone is a structural protein complexed with eukaryotic DNA to form a chromosome.
  50. What is the function of the nucleoulus?
    The nucleoulus synthesizes rRNA.
  51. What is the function of a ribosome?
    A ribosome is the sight of protein translation (assembly) during protein synthesis.
  52. Which part of the nervous system readies the body for "fight or flight"?
    The sympathetic nervous system.
  53. What is the function of the parasympathetic division of the nervous system?
    The parasympathetic division opposes the sympathetic division by slowing the body down and conserving energy.
  54. Which division of the nervous system inhibits digestion?
    The sympathetic division.
  55. Assuming codominance, what happens to the phenotype in the presence of two dominant alleles?
    The phenotype of each allele is simulataneously displayed (e.g., type AB blood).
  56. What are the components fo the hindbrain?
    The hindbrain is composed of the cerebellum, pons, and medulla oblongata.
  57. What is the function of the cerebellum?
    The cerebellum is responsible for coordination.
  58. What part of the brain controls autonomic activites?
    The medulla oblongata.
  59. What are the four regions of the spinal cord?
    Cervical, Thoracic, Lumbar, Sacral.
  60. What is the function of a dendrite?
    A dendrite conducts nerve impulses towards the cell body.
  61. What is the function of an axon?
    An axon conducts nerve impulses away from the cell body.
  62. What is the composition of a myelin sheath?
    In the CNS, myelin is composed of the membranes of oligodendrocyes. In the PNS, myelin is composed of the membranes of Schwann cells.
  63. What protein complex is responsible for the resting potential (-70mV) of a neuron?
    The Na-K pump.
  64. What are alleles?
    Alleles are different forms of the same gene that occupy the same position on homologous chromosomes.
  65. Define genotype.
    Genotype refers to the genetic makeup of an individual.
  66. Define phenotype.
    Phenotype refers to the physical manifestation of an individual's genotype.
  67. Define homozygous.
    Homozygous indivduals have two copies of the same allele for a given trait.
  68. Define heterozygous.
    Heterozygous individuals have two different alleles for a given trait.
  69. What is saltatory conduction?
    Saltatory conduction is the "jumping" of an action potential between the unmyelinated Nodes of Ranvier.
  70. What happens when an action potential reaches a synapse (in a mammal)?
    When an action potential reaches a synapse, the electrical signal causes the release of neurotransmitters from the presynaptic membrane into the synapse.
  71. What is the function of a sensory (afferent) neuron?
    A sensory neuron carries impulses from sensory organs to the brain and spinal cord.
  72. What is the function of a motor (efferent) neuron?
    A motor neuron transmits impulses from the brain and spinal cord to muscles or glands.
  73. What is the largest part of the human brain?
    The cerebral cortex.
  74. What is the function of the cerebral cortex?
    The cerebral cortex process and integrates sensory input and motor response, and controls memory.
  75. What is the function of the hypothalamus?
    The hypothalamus is responsible for visceral functions such as hunger, thirst, and sex drive.
  76. (T/F) The cerebral cortext is the relay center for visual and auditory impulses.
    False. The midbrain is the relay center for visual and auditory impulses.
  77. What are homologous structure?
    Homologous structures are similar in origin but not function (whale flippers/human arms).
  78. What are analogous structures?
    Analogous structures are similar in function but not in origin (insect wings/bird wings).
  79. What are vestigial structure?
    A vestigial structure is a remnant structure that has lost its ancestral function (tail bone of man).
  80. Name the four nitrogenous bases in DNA.
    Adenine, Cytosine, Guanine, Thymine.
  81. Name the purines and pyrimidines in DNA.
    Purines: Adenine and Guanine Pyrimidines: Cytosine and Thymine
  82. What is the base-pairing in DNA? How many H-bonds hold the bases together?
    • A-T (2 H-bonds)
    • C-G (3 H-bonds)
  83. Name three differences between RNA and DNA.
    RNA uses ribose instead of deoxyribose, uses Uracile instead of Thymine, and is single-stranded.
  84. What is transcription?
    The process whereby mRNA is synthesized from a DNA template.
  85. What is translation?
    The process whereby proteins are synthesized from a mRNA template.
  86. What is an exon? An intron?
    An exon is a coding sequence on a gene. An intron in a non-coding sequence on a gene.
  87. What is a codon?
    A codon is a 3-base sequence of mRNA that codes for a specific amino acid.
  88. What is an anticodon?
    An anticodon is a 3-base sequence on tRNA that is complementary to a mRNA codon.
  89. What is an operon?
    A gene that regulates (bacterial) transcription.
  90. What is an inducible system?
    An inducible system requires that presence of an inducer for transcription to occur.
  91. What is a repressible system?
    A repressible system is in constant state of transcription unless a corepressor is present to inhibit transcription.
  92. What is a retrovirus?
    A retrovirus is an RNA virus that codes for the enzyme reverse transcriptase, which uses the RNA as a template for DNA synthesis.
  93. What is a prophage (provirus)?
    A prophage is bacterial virus that has integrated into its host cell genome.
  94. (T/F) Females can express a sex-linked recessive trait.
    True, a female carrier and a male with the recessive trait will have 25% chance of giving birth to a female child with the recessive trait.
  95. What is nondisjunction?
    Nondisjunction is the failure of homologous chromosomes (or sister chromatids) to separte properly during cellular reproduction.
  96. (T/F) DNA synthesis proceeds in the 3' to 5' direction.
    False, 5' to 3' direction.
  97. What are the three types of RNA and where are their functions?
    • Messenger RNA- contains the codons for peptide chain synthesis.
    • Transfer RNA- transports amino acids to the ribosome during protein synthesis.
    • Ribosomal RNA- structural component of ribosomes.
  98. Which type of neuron serves as a link between motor and sensory neurons?
    Interneurons (associate neurons) link sensory and motor neurons.
  99. What are the two major subsystems of the nervous system?
    The two major subsystems of the nervous system are the central nervous system and the peripheral nervous system.
  100. What are the components of the central nervous system?
    The brain and spinal cord.
  101. Summarize Mendel's First Law (Law of Segregation).
    • Mendel's first law states that alleles segregate during meiosis; specifically:
    • -Genes exist in alternative forms (alleles).
    • -An individual inherits two alleles for each trait, one from each parent.
    • -The two alleles segregate during meiosis.
    • -If two different alleles are present, only one will be fully expressed.
  102. Summarize Mendel's Second Law (Law of Independent Assortment).
    Mendel's second law states that alleles of unlinked genes assort independently during meiosis.
  103. (T/F) In a resting neuron, Na+ concentration is higher inside the cell than outside the cell.
    False, [Na+] is higher outside a resting neuron.
  104. Do Na+ ions rush into or out of the cell during depolarzation?
    Na+ ions rush into a cell during depolarization.
  105. Do K+ ions rush into or out of the cell during repolarization?
    During repolarization, K+ ions rush out of the cell.
  106. (T/F) A neuron can conduct during the refractory period.
    False, the neuron is unable to respond to stimulus during the refractory period.
  107. What is hyperpolarization?
    Hyperpolarization refers to a state where the potential across the membrane is more negative than the resting potential.
  108. Which type of photoreceptor cell is specialized for color vision? Which type is specialized for low light conditions?
    Cones for color and rods for night vision.
  109. What is the fovea?
    The fovea is the region of the retina with a high density of cones.
  110. What are the components of the middle ear?
    The middle ear is composed of the tympanic membrane, malleus, incus, and stapes.
  111. What are the components of the inner ear?
    The inner ear is composed of the cochlea and organ of Corti.
  112. Where and how does ADH affect the nephron?
    ADH makes the distal convoluted tubule and collecting duct more permeable to H20.
  113. (T/F) Urine leaves the kidney via the utreter and leaves the bladder via the urethra.
  114. Is urine hypertonic or hypotonic to blood?
    Urine is hypertonic to blood.
  115. What are some functions of the liver?
    Liver functions include regulation of blood glucose, detoxification of toxins, beta-oxidation of fatty acids, destruction of old red blood cells.
  116. Which endocrine gland secretes epinephrine and norepinephrine?
    The adrenal medulla.
  117. (T/F) Epinephrine and norepinephrine return the body to its resting state and increase nutrional absorption.
    False, they slow down digestion and increase the basal metabolic rate.
  118. What are some of the effects of epinephrine?
    Increased heart rate, increased blood glucose level, increased blood supply to brain, muscles, and heart, decreased digestion and excretion.
  119. What is the difference between an endocrine gland and an exocrine gland?
    Endocrine glands secrete their hormones directly into the blood stream. Exocrine glands secrete substances that are transported by ducts.
  120. The anterior pituitary is regulated in part by what other endocrine gland?
    The hypothalamus regulates the anterior pituitary.
  121. Which two hormones are secreted by the ovaries?
    Estrogen and progesterone.
  122. What are the four phases of the menstrual cycle?
    Four phase of the menstrual cycle are follicular phase, ovulation, luteal phase, and menstruation.
  123. What is the corpus luteum?
    The corpus luteum develops from a ruptured follicle in the ovary and secretes estrogen and progesterone.
  124. Name the components of a typical bacterial cell.
    Cell wall, cell membrane, cytoplasm, ribosomes, flagella, and DNA.
  125. Where does respiration occur in the bacterial cell?
    The cell membrane is the site of respiration in bacteria.
  126. (T/F) All multicellular organisms are composed of eukaryotic cells.
  127. How does the pH in the interior of a lysosome compare with the pH in the rest of the cell?
    The interior of a lysosome is acidic and therefore has a lower pH than the rest of the cell.
  128. What would happed if a lysosome released its contents into the cytoplasm?
    The hydrolytic enzymes of the lysosome would digest the organelles and kill the cell. This process is known as autolysis.
  129. What is the function of a transport protein?
    A transport protein helps move polar molecules and certain ions across the cell membrane.
  130. What is the function of a cell wall?
    A cell wall protects the cell from external stimuli and desiccation.
  131. What type of laboratory method can be used to separate cells without detroying them?
    Low speed centrifugation.
  132. (T/F) Proteins synthesized by RER are secreted directly into the cytoplasm.
    False, they are secreted into the cisternae of RER and then sent to smooth ER, where they are secreted into vesicles.
  133. What is the function of the Golgi apparatus?
    The Golgi apparatus receives vesicles from smooth ER, modifies them, and repackages them into vesicles for distribution.
  134. What happens to a secretory vesicle after it is released from the Golgi apparatus?
    A secretory vesicle from the Golgi fuses with the cell membrane to release its contents via exocytosis.
  135. What is the primary purpose of the kidney?
    To regulate salt and water concentration in the blood.
  136. Where are amino acids, glucose, and vitamins reabsorbed in the nephron?
    Amino acids, glucose, and vitamins are reabsorbed into proximal convoluted tubule.
  137. Where in the loop of Henle does water passively diffuse out?
    The descending limb.
  138. (T/F) Water passively diffuses into the ascending limb.
    False, the ascending limb is impermeable to water.
  139. Name the hormones secreted by the thyroid gland.
    The thyroid gland secretes thyroxine and triiodothyronine (collectively known as thyroid hormomes), as well as calcitonin.
  140. How do thyroid hormones affect metabolism?
    Thyroid hormones increase metabolism.
  141. How does calcitonin affect the level of Ca2+ in blood plasma?
    Calcitonin decreases blood plasma calcium.
  142. What hormone does the parathyroid gland produce and what is its function?
    The parathyroid secretes parathyroid hormones, which serves to increase blood plasma calcium.
  143. What are the primary homeostatic organs in mammals?
    Kidneys, liver, large intestine, and skin.
  144. What are the three regions of a kidney?
    Pelvis, Medualla, and Cortex.
  145. (T/F) A nephron is situated such that the loop of Henle runs through the medulla.
  146. What is the function of prolactin?
    Prolactin stimulates the production of breast milk.
  147. What is the target gland of ACTH?
    ACTH acts on the adrenal cortex.
  148. What is the function of TSH?
    TSH causes the thyroid to uptake iodine and produce thyroid hormone.
  149. (T/F) LH and FSH are secreted only in females.
    False, LH and FSH are produced and secreted in males as well as females.
  150. (T/F) The large intestine functions as an excretory organ by getting rid of excess salts.
  151. In which layer of the skin are sweat glands, sense organs, and blood vessels locatetd?
    The dermis.
  152. Name all of the hormones secreted by the anterior pituitary gland.
    Growth hormone (GH), prolactin, adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH).
  153. (T/F) Aldosterone stimulates the reabsorption of Na+ and H20 form the distal tubule and collecting duct.
  154. Would high levels of aldosterone result in concentrated or dilute urine?
    Concentrated urine.
  155. How would low levels of aldosterone affect blood pressure?
    Low levels of aldosterone lead to reduced blood plasma volume and therefore reduced blood pressure.
  156. Would high levels of ADH (vasopressin) result in concentrated or dilute urine?
    High levels of ADH result in concentrated urine.
  157. (T/F) The testes secrete testosterone.
  158. (T/F) The pineal gland secretes melatonin.
  159. Which endrocrine organ secretes insulin and glucagon?
    The pancreas secretes insulin and glucagon.
  160. How does glucagon affect blood glucose levels?
    Glucagon increases blood glucose levels.
  161. How does insulin affect blood glucose levels?
    Insulin decreases blood glucose levels.
  162. (T/F) Too much insulin causes hypoglycemia.
  163. Name the three types of hormones secreted by the adrenal cotex.
    The three types of hormones are glucocorticoids, mineralcorticoids, and cortical sex hormones.
  164. What is the function of the cortisol?
    Cortisol is a glucocorticoid that increases the blood's glucose level.
  165. What important mineralcorticoid is released by the adrenal cortex?
  166. Name the hormones synthesized by the posterior pituitary.
    None. The posterior pituitary stores hormones (oxytocin and ADH) that are synthesized in the hypothalamus.
  167. What two hormones are released by the posterior pituitary and what are their functions?
    Oxytocin increases the strength of contractions during childbirth. Antidiuretic hormone (ADH, vasopressin) promotes the absorption of water in the nephron.
  168. (T/F) The hypothalamus regulates both the anterior and the posterior pituitary through hormone secretion and neurosecretory cells.
  169. What are the four blood types?
    A, B, AB, and O
  170. What is the Rh factor? How can the Rh factor complicate pregnancy?
    The Rh factor is an antigen on the surface of RBCs. Following the birth of an Rh+ child, an Rh- mother develops antibodies to the Rh factor. These antibodies can attack the blood cells of any future Rh+ fetuses carried by the mother.
  171. Which part of the brain controls breathing?
    The medulla oblongata.
  172. What is the function of immunoglobins (antibodies)?
    Antibodies attract other cells that can phagocytize an antigen or cause the antigens to clump together.
  173. Which segment(s) of the small intestine is/are primarily responsible for digestion?
    The duodenum.
  174. Which segment(s) of the small intestine is/are primarily responsible for absorption?
    The jejunum and ileum are primarily responsonsible for aborption.
  175. Why is pancreatic juice basic (high pH)?
    Pancreatic juice contains bicarbonate ion, which serves to neutralize the acidic chyme from the stomach. This is necessay because pancreatic enzymes work best at a slightly basic pH.
  176. (T/F) Bile is manufactured in the liver, stored in the gall bladder, and facilitates lipid digestion.
  177. What is plasma?
    Plasma is the liquid component of the blood.
  178. What are the cellular components of blood?
    The cellular components of blood are erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.
  179. Name the structure of the human alimentary canal (in order).
    Oral cavity, pharynx, esophagus, stomach, small intestine, large intestine.
  180. What enzymes does saliva contain and what does it digest?
    Saliva contains salivary amylase, which digests starch (carbohydrates).
  181. (T/F) All arteries carry oxygenated blood and all veins carry deoxygenated blood.
    False, pulmonary arteries and umbilical arteries carry deoxygenated blood while pulmonary veins and umbilical veins carry oxygenated blood.
  182. (T/F) The right side of the heart pumps blood into pulmonary circulation and the left side pumps blood into systemic circulation.
  183. Starting with the right atrium, trace the path of blood flow throughout the body.
    Right atrium, right ventricle, pulmonary arteries, pulmonary capillaries, pulmonary veins, left atrium, left ventricle, aorta, arteries, arterioles, capillaries, venules, veins, vena cava.
  184. Correctly sequence the following structure of the resiratory tract: Alveoli, trachea, larynx, nares pharynx, bronchi, bronchioles.
    Nares, pharynx, larynx, trachea, bronchi, bronchioles, alveoli.
  185. (T/F) Platelets play a key role in the immune response.
    False, platelets are key players in clor formation.
  186. Which proteins are essential for proper clotting?
    Thrombin and fibrin are essential for clot formation.
  187. What happens to interstitial fluid that doesn't diffuse into a capillary?
    Excess interstitial fluid is picked up by the lymphatic system and returned to the circulatory system.
  188. What are the three components of the large intestine?
    Cecum, colon, and rectum.
  189. What is the primary function of the large intestine?
    The large intestine functions primarily to absorb water and salts.
  190. Where does protein digestion begin? Lipid digestion?
    Protein digestion begins in the stomach and lipid digestion begins in the small intestine.
  191. Which component of the nervous system inhibits digestion? Which component promotes digestion?
    Sympathetic inhibits digestion and parasympathetic stimulates digestion.