Some sperm mitochondria enter an egg during fertilization, but as sperm mature these mitochondria are tagged with a protein (ubiquitin) that marks them for destruction. What organelle carries out this destruction process?
> Solve the equations in Exercises 39–44. x2 + 14x + 49 / x2 + 1 = 0
> Solve the equations in Exercises 39–44. 1 = 5 / x +6 / x2
> Solve the equations in Exercises 39–44. x + 14 / x + 4 = 5
> Solve the equations in Exercises 39–44. x + 2 / x – 6 = 3
> Solve the equations in Exercises 39–44. 21/x - x = 4
> Find the points of intersection of the pairs of curves in Exercises 31–38. y = 30x3 - 3 x2, y = 16x3 + 25x2
> The boiling point of tungsten is approximately 5933 Kelvin. (a) Find the boiling point of tungsten in degrees Celsius, given that the equation to convert x°C to Kelvin is k(x) = x + 273. (b) Find the boiling point of tungsten in degrees Fahrenheit. (Tu
> Find the points of intersection of the pairs of curves in Exercises 31–38. y = ½ x3 + x2 + 5, y = 3x2 - 12x + 5
> Graph the following equations. y = 3
> Draw the following intervals on the number line. [ -1, 4]
> A new plant forms from a stem that broke off of the parent plant. This is an example of ______. a. nodal cloning b. exocytosis c. asexual reproduction d. tissue culture propagation
> Exposure to ______ can trigger seed germination. a. light b. cold c. smoke d. all can be triggers
> Cotyledons develop as part of ______. a. carpels b. accessory fruits c. embryo sporophytes d. flowers
> Commands to move your right arm start in the _________. a. left frontal lobe b. right occipital lobe c. right temporal lobe d. left parietal lobe
> When you sit quietly on the couch and read, output from _______ neurons prevails. a. sympathetic b. parasympathetic
> Which neurotransmitter is important in reward-based learning and drug addiction? a. Ach b. serotonin c. dopamine d. epinephrine
> What chemical is released by axon terminals of a motor neuron at a neuromuscular junction? a. Ach b. serotonin c. dopamine d. epinephrine
> 1. Neurotransmitters are released by. a. axon terminals b. a neuron cell body c. dendrites d. glial cells 2. Which of the following are not in the brain? a. Schwann cells b. astrocytes c. microglia
> _____ relay messages from the brain and spinal cord to muscles and glands. a. Motor neurons b. Sensory neurons c. Interneurons d. Neuroglia
> Some survivors of disastrous events develop posttraumatic stress disorder (PTSD). Symptoms include nightmares about the experience and suddenly feeling as if the event is recurring. Brain-imaging studies of people with PTSD showed that their hippocampus
> Restoring a marsh that has been damaged by human activities is an example of ________. a. biological magnification b. bioaccumulation c. ecological restoration d. globalization
> Seeds are mature __________; fruits are mature _______. a. ovaries; ovules b. ovules; stamens c. ovules; ovaries d. stamens; ovaries
> The seed coat forms from the _________. a. integuments b. coleoptiles c. endosperm d. sepals
> Meiosis of cells in pollen sacs forms haploid __________. a. megaspores b. microspores c. stamens d. sporophytes
> An animal pollinator may be rewarded by ______ when it visits a flower of a coevolved plant (choose all that apply). a. pollen b. nectar c. hormones d. fruit
> 1. The arrival of pollen grains on a receptive stigma is called. a. germination b. fertilization c. pollination d. propagation 2. The ______ of a flower contains one or more ovaries in which eggs develop, fertilization occurs, and seeds mature. a. polle
> Why do eudicot trees tend to be wider at the base than at the top?
> Aboveground plant surfaces are covered with a waxy cuticle. Why do roots lack this protective coating?
> El Malpais National Monument, in west central New Mexico, has pockets of vegetation that have been surrounded by lava fields for about 3,000 years, so they have escaped wildfires, grazing animals, agricultural activity, and logging. Henri Grissino-Mayer
> In plants, fibers are a type of cell. a. parenchyma b. sclerenchyma c. collenchyma d. mesophyll
> El Malpais National Monument, in west central New Mexico, has pockets of vegetation that have been surrounded by lava fields for about 3,000 years, so they have escaped wildfires, grazing animals, agricultural activity, and logging. Henri Grissino-Mayer
> Biodiversity refers to ________. a. genetic diversity b. species diversity c. ecosystem diversity d. all of the above
> A prominent chin is typical of ______. a. Homo sapiens b. Homo habilis c. Homo erectus d. Homo floresiensis
> The position where a spinal cord enters the skull provides evidence about whether a fossil species _________. a. was nocturnal b. was carnivorous c. walked upright d. all of the above
> The 3.6-million-year-old footprints left by bipedal walkers in Tanzania were probably made by ______. a. australopiths b. Neanderthals c. modern humans d. Homo erectus
> The closest relatives of bonobos are ______. a. chimpanzees b. humans c. tarsiers d. Old World monkeys
> Match each structure with its description. cataract a. protects eyeball cochlea b. transmits vibration to bone eardrum c. functions in balance lens d. detects pheromones sclera e. interferes with vision fovea f. contains chemoreceptors taste bud g. focus
> _______ causes the pupil to widen. a. Low light b. Bright light
> Defective or missing ______ cause color blindness. a. hair cells b. rod cells c. cone cells d. neuroglia
> When you view a close object your lens gets ________. a. flatter b. rounder c. darker d. cloudier
> Visual accommodation involves adjustment to the shape or position of the _________. a. conjunctiva b. retina c. orbit d. lens
> Night vision begins with stimulation of _______. a. hair cells b. rod cells c. cone cells d. neuroglia
> Use of CFCs was banned in order to ______. a. lower sea level b. slow glacial melting c. discourage desertification d. prevent ozone destruction
> The organ of Corti contains receptors that signal in response to _______. a. heat b. sound c. light d. pheromones
> Substance P _______. a. increases pain-related signals b. is a natural painkiller c. is the active ingredient in aspirin
> Mechanoreceptors in the _______ send signals to the brain about the body’s position relative to gravity. a. eye b. ear c. tongue d. nose
> Cells lining the epididymis secrete a glycoprotein (beta-defensin) that coats sperm and facilitates their passage through cervical mucus. There are two common alleles for human beta-defensin: a wild-type allele (wt) and an allele with a deletion (del). T
> The cervix is the entrance to the ________. a. oviducts b. vagina c. uterus d. scrotum
> Cells lining the epididymis secrete a glycoprotein (beta-defensin) that coats sperm and facilitates their passage through cervical mucus. There are two common alleles for human beta-defensin: a wild-type allele (wt) and an allele with a deletion (del). T
> The ______ is a genetic dead end. a. polar body b. oocyte c. ovum d. sperm
> Cells lining the epididymis secrete a glycoprotein (beta-defensin) that coats sperm and facilitates their passage through cervical mucus. There are two common alleles for human beta-defensin: a wild-type allele (wt) and an allele with a deletion (del). T
> Fraternal twins are nonidentical siblings that form when two eggs mature and are released and fertilized at the same time. Explain why an increased level of FSH raises the likelihood of fraternal twins.
> Global climate change is causing ________. a. a decrease in sea level b. glacial melting c. acid rain d. all of the above
> Sexual reproduction ______. a. requires formation of gametes by meiosis b. produces offspring identical in their traits c. occurs only in vertebrates d. all of the above
> Cells lining the epididymis secrete a glycoprotein (beta-defensin) that coats sperm and facilitates their passage through cervical mucus. There are two common alleles for human beta-defensin: a wild-type allele (wt) and an allele with a deletion (del). T
> Drugs that interfere with sympathetic nerve signals are often prescribed for men who have high blood pressure. How might such drugs impair sexual performance?
> In the ________, neurons are arranged like maps that correspond to different parts of the body surface. a. retina b. somatosensory cortex c. basilar membrane d. occipital lobe
> Chemoreceptors play a role in the sense of ________. a. taste b. smell c. touch d. hearing e. both a and b f. all of the above
> Biological control of pest species __________. a. has no side effects b. involves mutualists c. uses natural enemies d. requires use of chemicals
> The oldest established land communities are _________. a. in the Arctic b. in temperate zones c. in the tropics d. on volcanic islands
> _________ steal parental care. a. Mutualists b. Commensalists c. Brood parasites d. Predators
> If you remove a species from a community, the population size of its main __________ is likely to increase. a. parasite b. competitor c. predator
> Species richness is greatest in communities __________. a. near the equator b. in temperate regions c. near the poles d. that recently formed
> With biological magnification, a _________ will have the highest pollutant load. a. producer b. primary consumer c. secondary consumer d. top-level consumer
> Growth of a forest in an abandoned corn field is an example of __________. a. primary succession b. resource partitioning c. secondary succession d. competitive exclusion
> With, one species evolves to look like another.
> ______ can lead to resource partitioning. a. Mutualism b. Parasitism c. Commensalism d. Interspecific competition
> A tick is a(n) _________. a. parasitoid b. ectoparasite c. endoparasite
> Which cannot be a symbiosis? a. mutualism b. parasitism c. commensalism d. interspecific competition
> Flightless birds that live on islands often have relatives on the mainland that can fly. The island species presumably evolved from fliers that, in the absences of predators, lost their ability to fly. Many island populations of flightless birds are now
> The type of physical environment in which a species typically lives is its ______. a. niche b. habitat c. community d. population
> With antibiotic resistance rising, researchers are looking for ways to reduce use of these drugs. Some cattle once fed antibiotic-laced food now get probiotic feed that can bolster populations of helpful bacteria in the animal’s gut. The idea is that if
> Burning fossil fuel releases ______ into the air. a. carbon dioxide b. nitrous oxide c. phosphates d. a and b
> Nitrogen fixation converts to ________. a. nitrogen gas; ammonia b. nitrates; nitrites c. ammonia; nitrogen gas d. ammonia; nitrates e. nitrogen gas; nitrogen oxides
> As a result of ________, an old animal usually has more pollutants in its body than a young one. a. bioaccumulation b. biological magnification
> Plant growth requires uptake of ________ from the soil. a. nitrogen b. carbon c. phosphorus d. both a and c e. all of the above
> Earth’s largest phosphorus reservoir is ________. a. the atmosphere b. the ocean c. sedimentary rock d. living organisms
> The ______ cycle is a sedimentary cycle. a. phosphorus b. carbon c. nitrogen d. water
> Greenhouse gases ________. a. slow the escape of heat energy from Earth into space b. are produced by natural and human activities c. are at higher levels than they were 100 years ago d. all of the above
> Earth’s largest carbon reservoir is ________. a. the atmosphere b. sediments and rocks c. seawater d. living organisms
> Most of Earth’s fresh water is _________. a. in lakes and streams b. in aquifers and soil c. frozen as ice d. in bodies of organisms
> Efficiency of energy transfers in aquatic ecosystems is typically higher than in land ecosystems because __________. a. aquatic food webs include more endotherms b. algae do not make lignin c. primary production cannot occur in water d. all of the above
> Primary productivity is affected by ________. a. nutrient availability b. amount of sunlight c. temperature d. all of the above
> All organisms at the top trophic level _________. a. capture energy from a nonliving source b. obtain carbon from a nonliving source c. would be at the top of an energy pyramid d. all of the above
> To assess the impact of human activity on the carbon dioxide level in Earth’s atmosphere, it helps to take a long view. One useful data set comes from deep core samples of Antarctic ice. The oldest ice core that has been fully analyzed
> Sulfur dioxide released by coal-burning power plants contributes to _________. a. ozone destruction b. sea level rise c. acid rain d. desertification
> Organisms at the lowest trophic level in a tallgrass prairie are all _________. a. two steps away from the original energy input b. autotrophs c. heterotrophs d. both a and b e. both a and c
> To assess the impact of human activity on the carbon dioxide level in Earth’s atmosphere, it helps to take a long view. One useful data set comes from deep core samples of Antarctic ice. The oldest ice core that has been fully analyzed
> In most ecosystems, the primary producers use energy from ________ to build organic compounds. a. sunlight b. heat c. breakdown of wastes and remains d. breakdown of inorganic substances in the habitat
> To assess the impact of human activity on the carbon dioxide level in Earth’s atmosphere, it helps to take a long view. One useful data set comes from deep core samples of Antarctic ice. The oldest ice core that has been fully analyzed
> Unrelated species in geographically separated parts of a biome may resemble one another as a result of ________. a. morphological divergence b. morphological convergence c. resource partitioning d. coevolution
> What biome borders on boreal forest? a. savanna b. taiga c. tundra d. chaparral
> If a mammal injures its leg, the resulting pain discourages the animal from putting too much weight on the leg while it is healing. An injured insect shows no such shielding response when its leg is injured. Some have cited the lack of such a shielding r
> Which is a somatic sensation? a. taste b. smell c. touch d. hearing e. a through c f. all of the above
> Most bats eat insects or fruit. Vampire bats, however, suck blood from birds or mammals. Like some snakes, and unlike any other mammals, vampire bats have thermoreceptors that can detect body heat given off by prey. Is the heat-detecting ability of vampi
> ______ is defined as a decrease in the response to an ongoing stimulus. a. Perception b. Visual accommodation c. Sensory adaptation d. Somatic sensation
> A compound extracted from the leaves of the shrub Stevia rebaudiana shows promise as a natural sugar substitute. The compound is 300 times sweeter than sugar, but it also has a slight bitter aftertaste. Given what you know about taste receptors, explain
> The pain of heartburn is an example of a ______. a. somatic sensation b. visceral sensation c. sensory adaptation d. spinal reflex
> Like other nocturnal carnivores, the ferret shown in Figure 33.14 has light-reflecting material in its choroid. Explain why the presence of reflective material in this layer of the eye maximizes the degree to which light excites photoreceptors. Explain a
> Male aggression is rare in bonobo society and common in chimpanzee society. Various authors have argued that either one species or the other should be considered a model for “natural” human behavior. Explain why, from the standpoint of relatedness, there
