BIOL 1000 Study Guide - Midterm Guide: Nucleoid, Lysosome, Microtubule

Exercise #5: The Nervous system and Perception

Task #1: Color vision

Introduction

In the human retina, there are two kinds of light-sensitive cells: rods and cones. These cells are located on the outside of the retina, away from the vitreous humor and against the choroid layer, and are covered by a later of bipolar and ganglion cells as well as neurons. Light enters the posterior chamber through the lens and must pass through several cell layers before it is absorbed by the rods and cones.

Cones are involved in color vision at daylight intensities. Generator potentials in a cone excite one neuron, giving high-level resolution vision. Cones will not cause neural firing at low light intensities and are, therefore, nonfunctional at night.

Rods provoke black-and-white vision at low light intensities. A bipolar cell associates with several rods, so that generator potentials sum in their effect. This assures neuronal firing at low light intensities and provides a highly sensitive vision but with less resolution.

Receptor convergence. A ganglion cell, which receives input from a number of rods, spread out over the retina, cannot pinpoint the source of a light stimulus as well as a ganglion cell, which is stimulated by a single photoreceptor. In the case of a ganglion cell receiving the added input of several rods, light hitting any one of the rods can cause a neural spike in the ganglion cell, but the brain has no way to know which rod was excited. It is therefore harder to pinpoint the location of light stimuli on the retina when the stimulus is detected by rods (as compared to cones). The result is that our ability to see detail, or our resolving power, is considerably lower under dim light conditions than under bright light conditions.

Dark adaptation. If you go from a lighted area to a very dark room, you will not be able to see. After about ten minutes, however, you begin to be able to see again. This occurs because the rhodopsin pigment, which gets broken down when it absorbs light, is continually re-synthesized in the rods. When there is very little light, very little rhodopsin gets broken down and the amount of rhodopsin gradually builds up, making the rod much more sensitive to dim light.

When light strikes a receptor cell, it triggers a photo-chemical reaction that leads to neuronal firing. If a rod or cone receives high-intensity light, the visual pigments will be temporarily bleached and will not absorb any more light. Within a matter of a few seconds, enzyme systems in the cells will restore the visual pigment to its light-absorbing form. This can be easily demonstrated. If, after viewing a bright light, the eye is quickly shut or turned to a dark wall, the bright image will persist as a positive afterimage because the high generator potential causes the continued firing of neurons. If the eye is cast on a lighter background after a few seconds, a negative afterimage, or a dark image of the object will appear. This is because the still bleached cells are not receptive to the light coming from the light background.

According to the Young-Helmholtz theory of color vision, there are three types of cone cells, which respond respectively to red, green, and blue light.

All other colors are perceived as the brain interprets impulses coming from a mix of these receptors. If an object of one color is viewed for a long period of time at high light intensity, the cones for that color will become bleached. The afterimage of the object will be seen in the complementary color.

The Exercise 6 PowerPoint will demonstrate afterimages to you. Use the slide show option to project the square of red light on your entire screen in a dark room. After staring intensely at the square for 30 seconds or so, without shifting your gaze, click enter to change the slide to a soft white. Continue staring at the screen as the change is made. What do you see? What was the color of the afterimage?

Repeat this experiment using a blue square. Before doing the experiment, hypothesize what color the afterimage will be according to the Young-Helmholtz theory.

Hypothesis to be tested: (2 pts)

What did you see when the experiment was conducted? (2 pts)

Was you hypotheses accepted or rejected? (1 pt)

Explain the colors seen in these afterimages using the Young-Helmholtz theory. (5 pts)

Question 1 An unknown element is found to contain 45 protons and an atomic mass of 64, what is its atomic number? A It cannot be determined. B 19 C 45 D 64 Question 2 The square above is based on the eye color of two parents, one of whom has brown eyes and carries the recessive gene for green eyes (a). What is the probability that a biological child of these parents will have brown eyes? A 0% B 25% C 50% D 100% The spleen functions are part of the _____ system. Which of the following completes the sentence above? A digestive B lymphatic C endocrine D circulatory Question 4 Which of the following is an example of deductive reasoning? A Only 21% of a town’s population have expressed a desire to ban all cars. Therefore, the new proposition banning cars in the state is not likely to pass. B People who brush their teeth regularly have fewer instances of heart disease. Therefore, good dentistry can prevent heart attacks. C All soccer players who play professionally can kick well. Therefore, any future soccer player who is recruited to play professionally will be able to kick well. D All secretaries are good typists. Cynthia is a secretary. Therefore, Cynthia is a good typist. Question 5 Which of the following is a possible cause of herniation of discs? A hepatitis B whiplash C plantar fasciitis D ulcer Question 6 Which of the following is a characteristic of the autonomic nervous system? A It regulates the voluntary control of body movements through the skeletal muscles. B It is the part of the nervous system consisting of the brain and spinal cord. C It regulates involuntary activity in the heart, stomach, lungs, and intestines. D It is thought to be the center of intelligence. Question 7 During photosynthesis, which two compounds are combined to create the output of glucose and oxygen? A Carbon dioxide and water. B Carbon dioxide and bicarbonate. C Bicarbonate and water. D Carbon dioxide and multiple alkaline substances. Question 8 Questions 8 & 9 are based on the following diagram: Which of the following is true about the frog? A It is a member of the salamandridae family. B It is a type of amphibian. C It is a non-vertebrate. D It is closer to most tetrapods than to most newts. Question 9 Questions 8 & 9 are based on the following diagram: Which statement can be inferred about amphibians? A All amphibians are salamandridae, but not all salamandridae are amphibians. B Some amphibians are vertebrates, but not all amphibians are vertebrates. C Some salamandridae are amphibians, but not all amphibians are tetrapods. D All amphibians are vertebrates, but not all vertebrates are amphibians. Question 10 What would this diagram be useful for? A determining outcomes for potential infection B diagnosing an infectious disease C controlling the spread of disease in undeveloped countries D training nurses to detect early onset symptoms of disease Question 11 What type of bond between the complementary bases of DNA stabilizes the double helix structure? A covalent B ionic C hydrogen D nuclear Question 12 Which of the following subatomic particles are found inside of an atom’s nucleus? A electrons, neutrons, protons B neutrons, protons C electrons, protons D electrons Question 13 Which of the following statements is true regarding trophic levels? A Tertiary consumers acquire more energy content than secondary consumers. B Producers acquire less energy than primary consumers. C Secondary consumers acquire more energy than primary consumers. D Tertiary consumers acquire less energy than primary consumers. Question 14 Why does the human eye perceive a red colored dress as the color red? A The molecules of the dress do not absorb red light wavelengths. B The molecules of the dress absorb green and blue light wavelengths. C A red dress will primarily absorb red light wavelengths. D A red dress will not absorb light wavelengths from non-red colors. Question 15 In a lab experiment designed to test the rate at which plants grow under artificial light, the kind of light used is which type of variable? A dependent B independent C random D responding Question 16 Which organ system is primarily responsible for regulating metabolism, mood, and growth? A respiratory system B digestive system C endocrine system D lymphatic system Question 17 In a vacuum, why doesn’t an elephant accelerate faster than a penny as it falls to the ground? A Vector components of an elephant are more complex than those of a penny. B An elephant is not a projectile, while a penny is. C They both have an acceleration of 9.8 m/s2. D The elephant is greater in mass but is slowed less by the effects of air resistance. Question 18 Which train described below would have the greatest momentum? A A 9500 kg train car moving at 200 mph B An 8000 kg train car moving at 215 mph C A 9300 kg train car moving at 190 mph D A 8600 kg train car mobbing at 195 mph Question 19 A scientist found that when an invasive species was introduced into a river, the population of salmon native to the region decreased. The type of correlation between these two populations could best be described as A a direct relationship. B an inverse relationship. C a direct and indirect relationship. D no decisive relationship. Question 20 The addition of a catalyst to a chemical reaction will have what effect? A Increase the energy required for the reaction to take place. B Increase the time required for the reaction to take place. C Increase the rate at which the reaction takes place. D Reduce the amount of products in the reaction. Question 21 The pharynx is part of what body system? A respiratory B muscular C lymphatic D circulatory Question 22 Which of the following is true about eukaryotic cells? A They do not contain lysosomes. B They contain one chromosome. C They do not contain a nucleus. D They contain mitochondria. Question 23 What characteristic of an element determines its specific isotope? A Number of protons. B Number of neutrons. C Number of electrons. D Number of quarks. Question 24 What is NOT true about RNA? A It contains a sugar called ribose. B Thymine is not one of its base pairings. C It is unstable in alkaline conditions. D Its sugar is more reduced than DNA’s sugar. Question 25 Which of the following scenarios would NOT give a normal distribution? A A distribution of the yearly income of families in the U.S. B The distribution of heights in a large sample of people. C The percentage of toxic wastes and pollution in the atmosphere vs. the lifespan of organisms in the location. D A curve with 97% of the population within the first two standard deviations. Question 26 In a cell, the Golgi apparatus is found in what location? A Inside the nucleus B Inside the mitochondria C In the cell wall D In the cytoplasm Question 27 Which taxonomic rank is the next-smallest after Order? A Phylum B Family C Species D Genus Question 28 In plants, ________ involves the formation of a _____? A cytokinesis, cleavage furrow B telophase, cell plate C cytokinesis, cell plate D prophase, DNA Question 29 Which base is NOT found in DNA? A guanine B cytosine C uracil D adenine Question 30 Which of the following layers of the atmosphere is the closest to space? A troposphere B stratosphere C mesosphere D thermosphere Question 31 Which is NOT one of the four basic types of tissue? A parenchyma B epithelial C nervous D connective Question 32 The stomach is _____ to the small intestine. Which of the following correctly completes the sentence above? A lateral B superior C posterior D proximal Question 33 Which of the following is the atomic mass of an atom containing 42 protons, 42 electrons, and 37 neutrons? A 42 B 79 C 84 D 121 Question 34 A patient who has suffered head trauma is not able to recognize people he has met around an hour earlier but is still able to recognize people he met before the injury. He most likely has damage to the: A Medulla Oblongata B Corpus Callosum C Hippocampus D Pituitary Gland Question 35 What process is illustrated in the diagram above? A meiosis B mitosis C replication D codification Question 36 Of the following, which is not a type of chemical bond? A ionic B covalent C polar D magnetic Question 37 If the amount of hydrogen in a balloon of fixed size is doubled, what happens to the mass and density of the balloon? A The mass and density both decrease. B The mass increases, but the density decreases. C The mass decreases, but the density increases. D The mass and density both increase. Question 38 If you have 200 mL of a 60% sodium chloride solution, how much NaCl is dissolved in the solution? A 20 g B 50 g C 80 g D 120 g Question 39 How many carbon dioxide molecules are required to balance the following reaction: 4C6H12O6 + 24O2 → _CO2 + 24H2O + Energy A 4 B 8 C 16 D 24 Question 40 The graph above records the death rate of two types of male flies a certain number of days after a chemical pesticide is sprayed. What is the probability a male methuselah fly will be alive 75 days after exposure to the pesticide? A 1/2 B 1/3 C 1/4 D 1/5 Question 41 A scientist wants to write an equation using the variables X, Y, and Z. What is the proper relationship between the variables if X represents time, Y represents energy, and Z represents power? A 2XY = Z B XZ = 2Y C Z = X/Y D Z = Y/X Question 42 What type of correlation is presented between price and quality? A strong direct correlation B weak direct correlation C strong indirect correlation D no correlation Question 43 What type of cells result from mitosis? A one diploid cell B two haploid cells C two diploid cells D four haploid cells Question 44 Cheetahs, rainbow trout, and inchworms belong to the same A Kingdom B Phylum C Class D Order Question 45 The presence of which hormone would NOT cause an increase in water retention? A Renin B ANP C ADH D Aldosterone Question 46 In which part of the heart does oxygenated blood flow out of? A Right ventricle B Left ventricle C Right atrium D Left atrium Question 47 Which of the following hormones are secreted directly by the hypothalamus? A melatonin B oxytocin C dopamine D calcitonin Question 48 Which of the following terms do these diagrams NOT portray? A Active transport B Facilitated Transport C Antiporter D Ion Channel

1.

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location.