Feralis Ch 6 Flashcards

Question

Intersexual selection

Answer 1

females choose superior males, which increases the fitness of the offspring. Because females invest more energy into their offspring, they want to maximize the quality of their offspring by picking fit males.

Answer 2

when males compete and fight with other males for better mating opportunities. Males increase fitness of offspring by maximizing quantity. Intrasexual selection favors traits like musculature, horns, large stature, etc.

Answer 3

the differences in appearance of males and females, which is a form of disruptive selection. This occurs because female choice leads to traits and behaviors in males that are favorable to females. Male traits like colorful plumage or elaborate mating behavior will be selected for by females.

Answer 4

this is a form of directional selection carried out by humans when they breed favorable traits, and is not natural selection.

Answer 5

Mutation, Sexual reproduction, Diploidy, Outbreeding, Balanced polymorphism (Heterozygote advantage, Hybrid Vigor (heterosis), Frequency-dependant selection (minority advantage)), Neutral variation, Geographic variation

Answer 6

new alleles could be introduced to the population with genetic mutations.

Answer 7

genetic recombination such as crossing over, independent assortment, and random joining of gametes can occur during sexual reproduction.

Answer 8

Diploid organisms have two copies of each chromosome. In heterozygous conditions, the recessive allele is stored for later generations, and thus more variations are maintained in the gene pool.

Answer 9

mating with unrelated partners results in mixing of different alleles and creating new allele combinations.

Answer 10

The maintenance of different phenotypes in a population. One phenotype is usually the best and thus has increased allele frequency. However, polymorphisms, the coexistence of two or more different phenotypes, can exist and be maintained: ``` Heterozygote advantage Hybrid Vigor (heterosis) Frequency-dependant selection (minority advantage) ```

Answer 11

When a heterozygote condition bears greater advantage than either homozygous conditions. For example, sickle cell anemia is a recessive trait, but being heterozygous for the trait confers resistance against malaria.

Answer 12

The superior quality of offspring resulting from crosses between two different inbred strains, species, or varieties of organisms. Hybrid superior quality results from reducing deleterious recessive homozygous conditions and increasing heterozygous advantage.

Answer 13

Occurs when least common phenotypes have a selective advantage. Common phenotypes are selected against. Rare phenotypes will increase in frequency and will then be selected against, repeating the cycle. For example, predators use search images of common phenotypes to find prey, allowing prey with rare phenotypes to escape. The rare prey phenotype eventually becomes common, and then the cycle repeats.

Answer 14

these are variations that are passed down without any selective value, such as fingerprints in humans.

Answer 15

variation of a species is dependent on climate or geographic conditions. A graded variation of a phenotype due to this is known as a cline. Variation from north to south environments is a north-south cline.

Answer 16

the introduction and removal of alleles from the population when individuals leave (emigration) or enter the population.

Answer 17

the random increase and decrease of an allele by chance. Genetic drift has a larger effect on small populations.

Answer 18

when a small group of individuals migrate to a new location, the gene pool of the small group will be less than the original population. After successive generations, the genetic makeup will be unique from the original population.

Answer 19

occurs when the population undergoes a dramatic decrease in size due to natural catastrophes or other events. The population is now vulnerable to genetic drift, and the gene pool is much smaller.

Answer 20

individuals choose mates based upon their particular traits. 1. Inbreeding - individuals mate with relatives. This changes genotype proportions but not allele frequency 2. Sexual selection - females choose males based on superior traits

Answer 21

If allele frequencies remain constant from generation to generation, then there is no evolution. In this situation, the Hardy Weinberg equation can be used to determine allele frequencies for a population.

Answer 22

1. No mutations - no new alleles can be introduced to the population 2. No natural selection - the environment is not impacting allele frequencies, and so traits are neutral 3. No gene flow - also happens as a result of no migration. An isolated population will have no gene flow 4. Large populations - this decreases the effects of genetic drift 5. Random mating - this decreases the chance of any allele from changing in frequency

Answer 23

p^2 + 2pq + q^2 = 1 (all individuals sum to 100%) p + q = 1 (all alleles sum to 100%) ``` p = frequency of the dominant allele q = frequency of the recessive allele p2 = frequency of homozygous dominant q2 = frequency of homozygous recessive 2pq = frequency of heterozygous ```

Answer 24

Speciation is the formation of new species. When gene flow ceases between two sections of a population, speciation begins. The first thing to happen in speciation is for gene flow between populations to be interrupted.

Answer 25

a group of individuals capable of interbreeding.

Answer 26

this speciation occurs when the population is divided by a geographic barrier. Interbreeding between two resulting populations is prevented as a result. The gene frequencies in the population can now diverge due to natural selection, mutation, and genetic drift. If the gene pool sufficiently diverges, the separated populations will not interbreed when the barrier is removed. If they cannot interbreed, that means a new species has formed. This form of speciation happens through: 1. Dispersal - the group is isolated by being physically removed from the original location of the larger group 2. Vicariance - the group is isolated by a geographic barrier but is in the same overall location of the larger group

Answer 27

this is the formation of new species without the presence of geographic barriers. This can occur in a few different ways: Balanced polymorphism, Polyploidy, Hybridization

Answer 28

natural selection due to polymorphism. Example: A population of insects has different colors. One color can camouflage to different substrates, but the insects in other colors cannot and will be eaten. Only insects with the advantageous color will mate as they are the ones that survive. The insects with this specific advantageous color are now isolated from other subpopulations

Answer 29

possessing more than the normal two sets of chromosomes, such as 3n or 4n, is considered polyploidy. This can lead to reproductive isolation, such as in plants. For example, nondisjunction of a 2n plant species could occur during meiosis, resulting in gametes that are still diploid instead of haploid. These diploid gametes could self-pollinate or reproduce with other gametes that have the same diploid number to form a 4n zygote, but the diploid gametes cannot reproduce with the normal 1n gametes. This new 4n zygote would be reproductively isolated from the original 2n species, and thus speciation can occur. In plants, the polyploidy can be further categorized into: Autopolyploidy, Allopolyploidy

Answer 30

when an organism has more than two sets of chromosomes, both of which are from the same parental species

Answer 31

when a organism has more than two sets of chromosomes, but they come from different species

Answer 32

two different closely related species mate and produce a hybrid along a geographic boundary called a hybrid zone Hybridization can result in more genetic variation. This means the hybrid can live beyond the range of either parents.

Answer 33

the rapid evolution of many species from a single ancestor. This occurs when an ancestral species is introduced to an area where diverse geographic and ecological conditions are available for colonization.

Answer 34

this type of isolation prevents fertilization before mating is attempted, and so a zygote is not formed. Habitat isolation, Temporal isolation, Behavioral isolation, Mechanical isolation, Gametic isolation

Answer 35

Species do not encounter each other because they live in different habitats, even if they live in the same geographical area

Answer 36

species reproduce at different seasons/times

Answer 37

some species will not reproduce with each other if they do not perform the correct courtship rituals

Answer 38

occurs when male and female genitalia are not compatible

Answer 39

male and female gametes do not recognize each other. The male gametes also may not survive in the environment of the female gametes

Answer 40

if a zygote does form, there are postzygotic methods to maintain reproductive isolation. Hybrid inviability, hybrid sterility, hybrid breakdown

Answer 41

the zygote fails to develop properly and dies before reaching reproductive maturity

Answer 42

hybrids become functional adults but cannot reproduce

Answer 43

hybrids produce offspring that have reduced viability/ fertility. The hybrid’s children cannot reproduce

Answer 44

this type of evolution occurs when two or more species that originated from a common ancestor become increasingly different over time as a result of speciation.

Answer 45

this type of evolution occurs when two unrelated species evolve to share more similar traits due to adapting to a similar environment (analogous traits).

Answer 46

this type of evolution occurs when two related species make similar evolutionary changes after their divergence from a common ancestor.

Answer 47

this evolution occurs when two species each causes the other one to evolve, which results in the evolution of both species. An example of this is the coevolution of predators and prey, where the evolution of a more effective predator will cause the prey to evolve better ways to defend itself.

Answer 48

this theory says that evolution occurs by the gradual accumulation of small changes. However, this is unlikely to be valid because intermediate stages of evolution are missing in the fossil record; fossils only reveal major changes in groups of organisms.

Answer 49

this theory says that evolutionary history consists of geologically long periods of stasis (stability) with little or no evolution followed by geologically short periods of rapid evolution. Absence of fossils revealing intermediate stages of evolution is considered data that confirms rapid evolutionary events.

Answer 50

The universe is 12-15 billion years old, the solar system is 4.6 billion years old, the earth is ~4.5 billion years old, the microfossils of prokaryotes are 3.6 billion years old, photosynthetic bacteria are 2.3 billion years old, and eukaryotes are ~1.8 billion years old.

Answer 51

1. Earth and the atmosphere formed through volcanoes 2. Primordial seas formed 3. Complex molecules were synthesized 4. Polymers formed and self-replicated 5. Organic molecules became protobionts 6. Primitive heterotrophic prokaryotes formed 7. Primitive autotrophic prokaryotes formed 8. Ozone layer formed which ended abiotic chemical evolution 9. Eukaryotes formed

Answer 52

the atmosphere had CH4, NH3, CO, CO2, H2, N2, H2O, S, HCl, and HCN gases. There was little to no O2!

Answer 53

As the earth cooled, gases condensed and formed a sea filled with water and minerals

Answer 54

the organic soup formed from inorganic compounds driven by energy from UV rays, lightning, heat, and radiation. The resulting organic compounds included acetic acid, formaldehyde, and amino acids

Answer 55

these scientists proposed the organic soup theory. They said that if there was O2 in the primordial atmosphere, no organic molecules would have formed because oxygen is very reactive. Oparin’s hypothesis was that the early Earth’s environment was reducing, which provides the chemical requirements to produce complex molecules from simple building blocks. An oxidizing environment would have broken the complex molecules apart

Answer 56

he tested Oparin’s theory and produced organic molecules. Miller & Urey sealed ammonia, methane, water, and hydrogen in a flask and simulated lightning; they created a simulated environment of the primordial Earth. The experiment produced several organic molecules, amino acids, and starting materials. However, no nucleic acids were made!

Answer 57

simple monomers became polymers through dehydration condensation reactions. Proteinoids are abiotically produced polypeptides. If we heat amino acids in the lab, they will dehydrate and form proteinoids, confirming the validity of this step

Answer 58

protobionts were precursors of cells, they are metabolically active but unable to reproduce. Microspheres/liposomes and coacervates (spontaneously formed lipid or protein bilayer bubbles) are experimentally (abiotically) produced protobionts that have some selective permeable qualities. We can also produce microsomes in the lab: vesicle- like artifacts from reformed pieces of the endoplasmic reticulum if the cell is broken up

Answer 59

they obtained energy by consuming other organic substances

Answer 60

heterotrophic prokaryotes mutated and gained the ability to produce their own food. An example of autotrophic prokaryotes is cyanobacteria

Answer 61

photosynthetic activity of autotrophs produced large amounts of oxygen. UV light and oxygen formed the ozone layer. The ozone layer absorbed UV light, thus blocking the energy needed for abiotic synthesis of organic materials. This causes the termination of primitive cells and abiotic evolution

Answer 62

the endosymbiotic theory explains that eukaryotic cells originated mutually among prokaryotes. The theory states that certain organelles like mitochondria and chloroplasts were once free-living prokaryotes. Other prokaryotes then phagocyted the mitochondria and chloroplast, and thus they lived in symbiosis. Evidence for this theory is seen with thylakoid membranes of chloroplasts that resemble photosynthetic membranes of cyanobacteria. Mitochondria and chloroplasts have double membranes and also have their own circular DNA that is not wrapped with histones, a trait of prokaryotes. The ribosomes of these organelles resemble those of bacteria, and they reproduce independently via a process similar to binary fission.

Answer 63

The modern atmosphere is roughly 78% nitrogen (N2), 21% oxygen, 1% argon, and some less important gases. Earth’s crust is 47% oxygen and 28% silicon.

Answer 64

structures that appear to be useless but had ancestral function. For example, humans have vestigial appendixes and tails, horses have vestigial splints, and pythons have vestigial reduced leg bones

Answer 65

two or more harmful species that are not closely related but share one or more common predators, have come to mimic each other's warning signals

Answer 66

this is slightly different from Mullerian mimicry in that a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator

Answer 67

all the alleles for any given trait in the population

Answer 68

this speciation occurs without a geographic barrier, so the population is continuous, but it still does not mate randomly. Individuals more likely to mate with geographic neighbors than with an individual farther out, so divergence may happen due to reduced gene flow and because of varying selection pressures across the population’s range. A population may occupy different niches that are adjacent and not isolated, so parapatric speciation could occur

Answer 69

this is very similar to allopatric speciation in that a population is isolated and prevented from exchanging genes from the “main” one, but one of the populations is much smaller than the other, so it is subject to accelerated genetic drift along with differing selection pressures

Answer 70

the gradual evolution of a species without any branching, is a straight path of evolution

Answer 71

a method of classification according to the proportion of measurable characteristics held in common between two organisms. The more characteristics they share, the more recently they diverged from common ancestor

Answer 72

a group of species that includes a common ancestor and all of its descendants. A clade is also known as a monophylum

Answer 73

a particular stage of an ecosystem

Answer 74

An organic matter that leaves an impression in rocks or in inorganic matter. Later, the organic matter decays and leaves a negative impression

Answer 75

a type of fossil formed when a mold is filled in

Answer 76

a small local population of the same species that regularly interbreed. For example, all the beavers along a specific portion of a river

Answer 77

chemosynthetic bacteria

Answer 78

green plants and photoplankton

Answer 79

amoebas, earthworms, and humans

Answer 80

a relationship between two species. The relationship can be: mutualistic, commensalism, parasitism

Answer 81

the relationship is beneficial to both species Tick bird and rhinos are in a mutualistic relationship because the bird gets food (ticks) and the rhino loses its ticks. Lichen (fungus and algae) is a mutualistic relationship because algae produces food for itself and the fungus via photosynthesis, while the fungus provides CO2 and nitrogenous wastes. Nitrogen-fixing bacteria and legumes are another example because the legumes provide nutrients for bacteria while the bacteria fixes nitrogen for the legumes. Protozoa and termites are an example too because protozoa digests cellulose for the termites, while termites protect and provide food for protozoa. The last example is intestinal bacteria and humans. The bacteria utilize our food but provide us with vitamin K

Answer 82

the relationship is beneficial to one species and neutral to the other species Examples are a remora and a shark, where the remora gets the food that the shark discards. Another example are barnacles and whales, where the barnacle gets wider feeding opportunities by associating with a whale while the whale is unharmed

Answer 83

the relationship is beneficial to one species but detrimental to the other species Parasites can be ectoparasites (cling to the exterior of the host) or endoparasites (live within the host). All viruses are parasites and infect hosts. Pathogenic bacteria are parasites that infect hosts as well, such as diphtheria infecting humans, anthrax in sheep, or tuberculosis in cows or humans. There are also parasitic fungi that can infect hosts, such as ringworm which infects humans. Tapeworms are well-known parasites that infect humans. Tapeworms are less dangerous, meaning the host will be more likely to live and allow the parasite to keep surviving. Thus, it is better for the parasite to not kill the host

Answer 84

shared traits derived from an evolutionary ancestor common to all members of a group

Answer 85

similar characteristics resulting from convergent evolution, therefore they are not derived from a common ancestor

Answer 86

this is also known as Occam’s Razor, which states that the simplest explanation is most likely correct. Phylogenetic trees are constructed using the Law of Parsimony. The fewest number of changes with respect to synapomorphies is likely the most correct representation of reality

Answer 87

the ancestral species and all its descendants

Answer 88

the ancestral species and some but not all descendants

Answer 89

the common ancestor of its members is not a part of the group

Answer 90

these are automatic and involve two nerves: afferent and efferent nerves. The response to stimulus is controlled at the spinal cord

Answer 91

these are automatic responses to significant stimulus. This is slower than simple reflexes because the nerves do not directly synapse with each other at the central nervous system like in simple reflexes. Instead, the nerves in complex reflexes are separated by an interneuron. Complex reflexes are controlled at the brain stem or even the cerebrum. An example of a complex reflex is the startle response which is controlled by the reticular activating system

Answer 92

these are behaviors that are innate, or inherited. An example of an instinctual behavior is in mammals who care for their offspring by female parents.

Answer 93

these are innate behaviors that follow a regular, unvarying pattern. Fixed action patterns are initiated by a specific stimulus called a sign stimuli. The sign stimuli is called a releaser when it is between members of the same species. In many FAPs, the action will be completed even if the original sign stimuli is removed. The FAP is completed even if the original intent of the behavior cannot be fulfilled. Reflexes are technically FAPs. An example of a FAP is when a goose methodically rolls an egg lying on the edge back to the nest. Even if the egg is removed after the goose starts the FAP, it will still perform the action. The sign stimuli is the egg outside the nest. Another example of an FAP is male stickleback fish defending territory against any object with red undersides.

Answer 94

this is an innate program for acquiring specific behaviors only if the appropriate stimulus is experienced during the critical/sensitive period. Once acquired, the trait is irreversible. It can influence sexual selection. A well-known example of imprinting are when graylag goslings accept any moving object as their mother during the first day of life. Another example is salmon that return to their birthplace to breed based on imprinted odors associated with the birthplace.

Answer 95

this occurs when an animal recognizes (learns) that events are connected. This allows individuals to benefit from exposure to unexpected repeated events. There are several forms of associative learning. Classical conditioning, trial-and-error learning (operant conditioning), Spatial learning

Answer 96

the most well- known example of classical conditioning are Pavlov’s dogs. Dogs naturally salivate when presented with food. This salivation caused by food is called the unconditioned response which is an innate reflex, and the food stimulus is the unconditioned stimulus. Pavlov then rings a bell when food is presented, and after some time, the dogs associated the bell sound with the food stimulus. However, ringing a bell with no food during the beginning of the experiment will not cause any response in the dog because the bell sound was still a neutral stimulus. At the end though, the dogs ended up salivating just at the sound of the bell without needing the food/unconditioned stimulus. Thus, the bell sound became the conditioned stimulus that will elicit a response even in the absence of the unconditioned stimulus. The salivation caused by the conditioned stimulus is called the conditioned response/reflex.

Answer 97

this is another form of associative learning that occurs when an animal connects its own behavior with either a punishment or reward. If the animal’s response is rewarded/ reinforced, the animal will repeat its behavior. If the animal’s response is punished, the animal will avoid that behavior. Punishment and reward can either be positive or negative (positive punishment, negative punishment, positive reward, negative reward). Positive means adding something, and negative means removing something.

Answer 98

adding something bad to decrease a behavior (e.g. hitting an animal when it bites someone)

Answer 99

taking away something good to decrease a behavior (e.g. not giving treats to an animal when it does not follow orders)

Answer 100

adding something good to increase a behavior (e.g. giving treats to a dog when it follows orders)

Answer 101

taking away something bad to increase a behavior (e.g. taking off an electric shock collar of a dog when it follows orders)

Answer 102

The learned behavior can be reversed in the absence of reinforcement. This is called extinction. The recovery of a conditioned response to a conditioned stimulus after a previously extinguished response is called spontaneous recovery.

Answer 103

another form of associative learning is spatial learning. The animal associates landmarks with a specific location. The animal then may associate that location as safe or dangerous and can return to that location. An example of spatial learning are wasps being able to associate pinecones with the location of their nest. Upon removal of the pinecones, this association is lost.

Answer 104

this is learned behavior that allows an animal to disregard meaningless stimuli. This allows individuals to ignore repetitive events known to be inconsequential and remain focused on other, more meaningful events. An example of this is when anemone will not react to being repeatedly poked with a stick. Usually, anemone will react when they contact something because it may be food, but the anemone will learn after being repeatedly poked with a stick that the stick is not food.

Answer 105

The opposite of habituation is sensitization: an increased response to repeated stimulus.

Answer 106

this is when an animal copies the behavior of another animal without having experienced any feedback themselves. An example are when monkeys see one monkey washing off potatoes in the water, and the rest follow.

Answer 107

when an animal is exposed to a new situation they have never seen before, yet they still perform a behavior that generates a positive outcome. Observational learning and insight provide a mechanism to learn new behaviors in response to unexpected events without receiving reinforcement. This reduces time for new behaviors to be acquired. An example is a chimpanzee stacking boxes to reach bananas previously out of reach.

Answer 108

Some behaviors appear learned but are actually innate behaviors that require maturation (e.g. birds appear to learn to fly by trial and error or by observational learning, but if raised in isolation, they will fly on their first try if physically capable. The flight ability is innate but requires physical maturation.

Answer 109

Daily cycles of behavior are circadian rhythms. Learning involves adaptive responses to the environment. In higher animals, the capacity for learning is closely associated with the degree of neurological development.

Answer 110

this is when an organism responds to stimuli similar to the original stimulus but not identical to the original conditioned stimulus.

Answer 111

this is the ability of the learning organism to differentially respond to slightly different stimuli (e.g. an animal only responding to sounds in the 990 to 1010 Hz range).

Answer 112

this is a gradient where the further a stimulus is from the original conditioned stimulus, the lesser of the magnitude of response in the animal.

Answer 113

an undirected (without direction) change in the speed of an animal’s movement in response to a stimulus. An animal can slow down in a favorable environment and speed up in an unfavorable environment. An example are animals scurrying when a rock is lifted up

Answer 114

a directed movement in response to a stimulus. Movement is either toward or away from the stimulus. Phototaxis is the movement towards light. Examples are moths moving toward light and sharks moving to food odors

Answer 115

this is the long-distance, seasonal movement of animals. This is usually in response to the availability of food or the degradation of environmental conditions. Examples of migrational animals are whales, birds, elk, insects, and bats. These animals can move to warmer climates. Evidence suggests there is a genetic basis to migration

Answer 116

chemicals used for communication are called pheromones. Chemicals that trigger reversible behavioral changes are called releaser pheromones. Chemicals that cause long term physiological (and behavioral) changes are called primer pheromones. Some pheromones trigger a response via smell, others trigger a response when eaten. Ants use formic acid to mark a trail to food which is an example of releaser pheromones. Queen bees and ants secrete primer pheromones to prevent the development of reproductive capabilities. Some pheromones are territorial, e.g. cats and dogs pee on territory to claim it. Pheromones can act as alarm symbols, e.g. minnow alarm response. Pheromones can act as sex attractants, territory markers, and accelerate reproductive maturity

Answer 117

communication can be done via visual displays. These displays can be used to signify aggression or used during courtship. Agonistic behaviors happen when an animal competes for territory, food, or a mate. Agonistic behaviors can be broken down into threats, aggression, and submission. Male sage grouses assemble into groups (leks) to perform a courtship dance. Another example of a ritual is the stickleback fish. The female is attracted to the red belly of a male. The female adopts a head-up posture to initiate courtship, the male makes a zigzag motion, and the female follows the male to the nest. If the nest is acceptable, the female enters and deposits eggs in response to the male prodding her tail. The female then leaves, and the male enters and fertilizes the eggs. The red belly, head- up posture, zigzag motion, and swimming to the nest are all visual cues here.

Answer 118

an example of a threat is a wolf baring its teeth

Answer 119

fighting between animals. However, this is usually dangerous to both parties

Answer 120

an example is an animal laying on its back to portray submission to another animal

Answer 121

this type of communication uses sounds. These sounds are commonly used for communication over long distances, through water, and at night. The sounds may be used to warn danger, to communicate reproductive readiness, for species recognition, as warning against rivals, etc. Whales can use infrasound which can be heard for hundreds of miles by other whales. Male birds also use auditory communication to attract other females

Answer 122

this type of communication between animals involves touch. Tactile communication is common in social bonding, infant care, grooming, and mating

Answer 123

Bees use auditory, tactile, and chemical communication to communicate food proximity. They perform a waggle dance to communicate all this information.

Answer 124

The goal of foraging is to maximize the amount of food eaten and to minimize energy expenditure and risk. Foraging is not just eating but also the activities an animal uses to search for, recognize, and capture food. Herds, flocks, and schools Packs Search images

Answer 125

there are several advantages to being in herds. They can cooperate and carry out a behavior more successfully as a group. Some benefits of being in a herd are: Concealment Vigilance Defense

Answer 126

most individuals in | the flock are hidden from view

Answer 127

in a group, individuals can trade off foraging and watching for predators. There are also more individuals watching out for predators

Answer 128

a group of individuals can shield their young or mob a predator

Answer 129

being part of a pack enables members to corner and successfully attack large prey

Answer 130

search images help animals find favored or plentiful food by using a specific, perhaps abbreviated ‘image’ of the target. An example is a cheetah using a search image (seeing black and white coloration) to find a zebra

Answer 131

this consists of threats, aggression, and submission. Agonistic behavior originates from competition for food, mates, or territory. Agnostic behavior is ritualized, so injuries and time spent in contests are minimized

Answer 132

animals in a hierarchy have different levels of power and status depending on their rank in the group. Having a hierarchy does minimize fighting for food and mates

Answer 133

a linear order of status used to describe the dominance hierarchy in chickens

Answer 134

the active possession and defense of territory to ensure adequate food and place to mate

Answer 135

this is seemingly unselfish behavior that appears to reduce the fitness of an individual. An example of altruistic behavior is when an animal risks its safety in defense of another, or when an animal helps another individual of the same species to rear its young. Altruistic behavior actually increases inclusive fitness. Inclusive fitness is the fitness of an individual plus its relatives who share some identical genes.

Answer 136

this is natural selection that increases inclusive fitness. Examples of kin selection are: (i) When a squirrel sounds an alarm when a predator comes. This is risky to that squirrel and reveals its presence, but this action saves its daughters, mothers, sisters, and aunts (ii) In bees, males are haploid (born from an unfertilized egg of a queen) and female workers and queens are diploid (from fertilized eggs). Females are highly related to each other because they have the same father whose genes all come from a queen mother. Inclusive fitness of female workers is greater if she promotes production of sisters by nurturing the queen than if she produced her own offspring

Answer 137

this is when unrelated members of the same species help each other. This tends to be in species with stable social groups that are likely to meet again, thus there is potential future benefit

Answer 138

the principle that for natural selection to favor an altruistic act, rB > C. (r) is the genetic relatedness between the altruist and the relative. (B) is the amount of genes the relative can pass on after it is helped by an altruist. (C) is the altruist’s direct fitness, which is the number of genes that animal can pass on by itself, disregarding relatives. If when (r) and (B) is multiplied and is greater than (C,) then altruistic behavior can occur

Answer 139

a pacifying social behavior that seeks to pacify aggression or to avoid being attacked by showing an inferior social stance (e.g. moving/turning away).

Answer 140

one male mating with one female

Answer 141

can be split into polygyny (one male mating with multiple females) and polyandry (single female mating with multiple males)

Answer 142

when individuals in a population copy the mate choice of others.

Answer 143

evolutionary game theory refers to the successful outcome of mating depending on dynamic, constantly shifting strategies of all the individuals involved. In evolutionary terms: the fitness of a particular behavioral phenotype is influenced by the behavior of other phenotypes in population. One common example of game theory in biology is the side- blotched lizard population with three different throat colors. The orange colored lizards are aggressive and mate with numerous females across large areas. The yellow colored lizards are more passive and closely resemble female lizards, allowing them to sneak into the territory of orange lizards , successfully mate, and eventually take majority control of the population. The blue colored lizards mate with only one female lizard but guard them closely - they are unable to compete against orange lizards, but their closeness to their mate prevents yellow lizards from being able to sneak in and take over. Thus there is a constantly shifting majority population due to the rock-paper-scissor like dynamic at play: orange lizards can overcome blue lizards due to their aggression, but are susceptible to being taken over from within by yellow lizards. Yellow lizards can overcome orange lizards through their sneaky behavior, but are unable to fool blue lizards. Blue lizards cannot be fooled by yellow lizards, but can be defeated in combat by orange lizards. The majority lizard color within any given population is therefore always shifting based on the prevailing lizard group and its individual strengths/weaknesses

Answer 144

a one-shot, big-bang reproduction. Many offspring are produced in a single reproductive opportunity. The survival rate of offspring is low but there is a higher number of offspring. This method is better for variable and unpredictable environments. Salmon exhibit semelparity.

Answer 145

repeated reproduction. There are relatively few but large offspring each time reproduction occurs. The parents tend to care for their offspring so the offspring survival rate is higher. This method is more favorable in dependable environments where adults are likely to survive and breed again, and competition for resources may be intense. Humans exhibit iteroparity.

Answer 146

Abiotic factors are nonliving. These include resources such as temperature, climate, light, water availability, and topology.

Answer 147

this is the zone in water where light penetrates. All aquatic photosynthesis occurs in this zone

Answer 148

this zone in water has almost no light penetration. Only animals and other heterotrophs exist here

Answer 149

Biotic factors are all living things that directly or indirectly influence the life of the organism. Abiotic and biotic factors are responsible for limiting the geographic distribution of species.

Answer 150

a group of individuals of the same species living in the same area.

Answer 151

a group of populations living in the same area.

Answer 152

describes interrelationships between organisms in a community and their physical environment.

Answer 153

combination of all the ecosystems of the earth. The biosphere includes the atmosphere, hydrosphere, lithosphere, and geosphere as well.

Answer 154

type of place where an organism usually lives. The habitat includes all the other organisms present as well as the physical and chemical environment.

Answer 155

this describes all the biotic and abiotic resources in the environment used by an organism. When an organism is said to occupy a niche, certain resources are consumed or certain qualities of the environment are changed in some way by the presence of the organism (exploited). No two species can occupy the same niche indefinitely. When two organisms occupy the same niche, they compete for food and mate at the same time of the year.

Answer 156

N, the total number of individuals in population

Answer 157

the total number of individuals per area or volume occupied

Answer 158

describes how individuals in a population are distributed. The dispersion may be clumped, uniform, or random

Answer 159

the description of the abundance of individuals of each age. The shape of the age graph changes based on the reproductive rate

Answer 160

how mortality of individuals in a species varies during their lifetimes. Can be described using a curve which is further grouped into different types: type I, II, III

Answer 161

most individuals survive to middle age but mortality increases quickly in old age. Humans have a type I survivorship curve

Answer 162

the probability of survival is generally constant and independent of age. Hydras have a type II survivorship curve

Answer 163

most individuals die young, with few surviving to reproductive age and beyond. Oysters are an example. This type of survivorship is typical of species that produce free- swimming larvae. Most of the larvae die and only a few survive to become adults

Answer 164

the maximum growth rate of a population under ideal conditions (unlimited resources and no restrictions). The following factors contribute to the biotic potential of a species: age at reproductive maturity, clutch size (number of offspring produced at each reproduction), frequency of reproduction, reproductive lifetime, and the survivorship of offspring that reach reproductive maturity

Answer 165

the maximum number of individuals of a population that can be sustained by a habitat

Answer 166

elements that prevent a population from reaching its full biotic potential. There are two categories: (i) Density-dependent (ii) Density-independent

Answer 167

the limiting effect becomes more intense as the population density increases. Competition for resources, the spread of disease, parasites, predation, and toxic effects of waste products are examples of density-dependent limiting factors. In some cases, reproductive behavior is abandoned when the population attains a high density

Answer 168

the limiting effect’s intensity occurs independently of density of the population. Examples include natural disasters or big temperature changes

Answer 169

r = (births - deaths)/N = b - m ∆N/∆t = rN = births - deaths = bN - mN

Answer 170

when the reproductive rate (r) is at its maximum (biotic potential)

Answer 171

Occurs whenever the reproductive rate (r) is greater than zero. This creates a J- shaped curve. The maximum rate is actually constant in this model, but the population accumulates more new individuals per unit time when it is larger, thus it curves to be more steep over time. If resources are unlimited, populations exhibit exponential growth

Answer 172

occurs when limiting factors restrict the size of the population to the carrying capacity of the habitat. The equation is: delta N / delta t = (r)*(N)*[(K-N)/K] where K is the is carrying capacity, otherwise known as the maximum population size that a particular environment can sustain When the population size increases, the growth rate decreases and reaches 0 when the population size reaches the carrying capacity. The curve is s- shaped. Note that ZPG (zero population growth) occurs when the birth and death rates are equal (r = 0). There are also technically more factors than just births and death; immigration and emigration also affect population dynamics, but we mostly ignore that for the purpose of equations

Answer 173

population size fluctuates in response to varying effects of limiting factors. When the population grows over carrying capacity, the population may then be limited to a size lower than the initial K due to the damage caused to the habitat. Thus K may be lowered or the population may crash to extinction. There may be associations (not necessarily causes!) in cycle fluctuations between the population sizes of two animal species with predator/prey ecology. Predator/prey ecology would show an out of sync but similar cycle, since one group is always responding with delay. This is because the decline of a predator allows the prey to recover. However, parasite/host ecology is in perfect sync because the parasite relies on the host directly for survival. When one thrives, so does the other in full sync. Parasites may be more or less numerous than the host

Answer 174

K-selected population R-selected population

Answer 175

in this type of population, the members have low reproductive rates with longer maturation times, and their size is roughly constant at K (ex. human population). The population levels out at the carrying capacity. Remember that carrying capacity is a density dependent factor. Growth curves are sigmoidal because the carrying capacity levels it off. Competition among individuals tends to be stronger and there is a limitation imposed by resources. Because of strong parental care, most organisms survive, and so K-selected species have a type I survivorship curve

Answer 176

these species have rapid exponential population growth. They have numerous offspring that are small and have fast maturation, so little parental care is needed (ex. bacteria). They are generally found in rapidly changing environments affected by density independent factors. R- selected species are also characterized by opportunistic species (e.g. grasses, insects that quickly invade a habitat and reproduce). These species have growth curves that are exponential. The population densities are well below carrying capacity, so there is little competition faced. R-selected species have a type III survivorship curve

Answer 177

human population growth has been exponential since about 1000 years ago. This is enabled by: increase in food supply, reduction in disease, reduction in human wastes, and habitat expansion because of advancements allowing the inhabitance of previously uninhabitable places. The rate is still increasing, but it is slowing down.

Answer 178

bacterial growth has 4 phases plotted as the logarithm of bacteria # vs time. The first phase, lag phase, is when bacteria are adapting to growth conditions. Individual bacteria are maturing but are not yet able to divide. The second phase, log phase (exponential phase), is the exponential growth of the population as it doubles with every time period (using log # produces a straight line here). The third phase, stationary phase, is when the growth rate equals the death rate due to growth-limiting factors. The fourth phase, death phase, is when bacteria die.

Answer 179

the aggregate land and water area necessary to produce all the resources to sustain an individual/group of people and absorb all their wastes.

Answer 180

this is the overall variety of different kinds of organisms in a community and consists of two components: 1. Species richness reflects the diversity of a community by describing the total number of different species present 2. Relative abundance is the amount of individuals of each species

Answer 181

species diversity is measured by the Shannon diversity index. The higher the value, the more diverse the community. Higher diversity communities are often more resistant to invasive species.

Answer 182

* Species richness generally declines along a latitudinal gradient from the tropics to the poles due to evolutionary history (tropics are “older”) and climate. In terrestrial communities, sunlight and precipitation correlate with diversity and can be measured via evapotranspiration. Evapotranspiration measures the evaporation of water from soil and plants and is a function of solar radiation, temperature, and water availability. Evapotranspiration is highest in hot areas with abundant rainfall * Species richness is directly related to a community’s geographic size, which is described with a species-area curve: increases in area leads to increases in the diversity of habitats, which leads to increases of species * Species richness on islands depends on island size and distance from mainland. Equilibrium is reached when new immigrations are balanced by extinctions

Answer 183

when two species compete for exactly the same resources (or occupy the same niche), one is likely to be more successful. The principle states that no two species can sustain coexistence if they occupy the same niche.

Answer 184

when two species occupy the same niche but pursue slightly different resources, individuals can minimize competition and maximize success through resource partitioning. This way, multiple species can survive relatively near each other but in slightly different niches.

Answer 185

as a result of resource partitioning, certain traits allow for more success in obtaining resources in their partitions. This reduces competition and increases the divergence of features. Thus, character displacement occurs where unique differences among species diverge even more when they coexist near each other.

Answer 186

the niche that an organism occupies in the absence of competing species is its fundamental niche. In other words, the fundamental niche is the area that a species could potentially survive in. The realized niche is the area that the species actually lives in due to factors such as competitors. When competitors are present, the multiple species may be able to coexist by occupying their realized niches. They coexist by occupying areas of the niche that do not overlap, so there is no competition for resources.

Answer 187

kills and eats another animal

Answer 188

spends most of its life living on a host and obtaining nourishment by feeding off the host’s tissues. The host usually does not die until the parasite has completed at least one life cycle

Answer 189

this is an insect that lays its eggs on a host (insect or spider). After the eggs hatch, the larvae obtain nourishment by consuming the host's tissues. The host eventually dies, but not until the larvae complete development and begin pupation

Answer 190

an animal that eats plants. Granivores are seed eaters and act like predators because they totally consume the organism. Grazers (animals that eat grasses) and browsers (animals that eat leaves) only eat part of the plant and thus weaken it

Answer 191

some species have positive effects on the survival and reproduction of another species without necessarily living in direct and intimate contact for symbiosis. This is common in plant ecology, e.g. black rush makes soil more hospitable for other plant species in the same zone.

Answer 192

saprophytes are protists and fungi that decompose dead organic matter externally and absorb nutrients.

Answer 193

consume dead animals directly (ex. Vultures, hyenas, bacteria of decay).

Answer 194

competition between members of the same species, and it is influenced by disruptive (competition) and cohesive (reproduction and protection from predators and weather) forces.

Answer 195

Interspecific competition is between members of different species, and is ultimately negative for both since they are competing against each other for resources.

Answer 196

occurs directly between individuals via aggression, etc. Other individuals are directly prevented from physically establishing themselves on the habitat to prevent the sharing of mutual resources. This can be done via the mechanism of allelopathy, which is the production of biochemicals by an organism to influence the growth/survival/reproduction of other organisms.

Answer 197

occurs indirectly through the depletion of a common resource.

Answer 198

occurs between two species preyed upon by the same predator. E.g. species A and B are hunted by C. If the amount of A increases, then this will lead to the survival of more predator C, which in turn hunts more of B, thus decreasing them.

Answer 199

these fish live in a hypo-osmotic environment which causes an excess intake of water. Thus, the fish seldom drink and excrete dilute urine

Answer 200

live in a hyper-osmotic environment. The fish are constantly drinking and excreting salt across their gills

Answer 201

secrete solid uric acid crystals to conserve water

Answer 202

possess waxy cuticles on the leaf surface and stomata. Stomata are on the lower leaf surfaces only. Leaves are shed in winter. Desert plants have have extensive root systems, fleshy stems, spiny leaves, extra thick cuticles, and few stomata

Answer 203

vast majority of plants and animals are poikilothermic. This means their body temperature is close to that of their surroundings, so their metabolism is radically affected by the environmental temperature

Answer 204

homeothermic organisms make use of the heat produced by respiration. Physical adaptations like fat, hair, and feathers retard heat loss. Mammals and birds are warm-blooded

Answer 205

These are toxic chemicals produced in plants that discourage would-be herbivores because they are toxic to herbivores. Examples of secondary compounds are tannins in oaks and nicotine in tobacco. Tannins in plants taste bitter and discourage herbivores from eating them

Answer 206

camouflage is any color, pattern, shape, or behavior that enables an animal to blend in with its surroundings. Both prey and predator benefit from camouflage

Answer 207

a conspicuous pattern or coloration of animals that warns predators that they sting, bite, taste bad, are poisonous, or are otherwise to be avoided

Answer 208

occurs when several animals, all with some special defense mechanism, share the same coloration. This way, the predator only has to learn that one pattern is bad instead of lots of variants. Examples are yellow and black body markings from bees, yellow jackets, and wasps

Answer 209

occurs when an animal without any special defense mechanism mimics the coloration of an animal that does possess a defense. Coloration, camouflage, mimicry, etc. are passive defenses. Active defenses are hiding, fleeing, defending but can be costly in energy

Answer 210

pollination of many kinds of flowers occurs as a result of coevolution of finely-tuned traits between flowers and pollinators. For example, red tubular flowers coevolved with hummingbirds that are attracted to the color red. The tubular flowers provide nectar to hummingbirds in exchange for pollen transfer

Answer 211

Ecological succession is the change in composition of species, organisms and vegetation over time. It describes how one community is gradually replaced by another group of species. As succession progresses, the diversity (number of species in a community) and total biomass (total mass of all living organisms) increase. A final successional stage of constant species composition (climax community) is attained and unchanged until destroyed by some catastrophic event (blowout). Succession has a factor of randomness that makes it hard to predict. Successional stages may not occur in an expected order. Some species are established randomly due to influences of climate, season, or due to which species arrived first. Sometimes, a stable climax community is never achieved due to frequent disturbances (e.g. fires).

Answer 212

1. Substrate texture 2. Soil pH 3. Soil water potential 4. Light availability 5. Crowding 6. Pioneer species

Answer 213

the substrate texture may change from solid rock, to fertile soil, to sand or others

Answer 214

may decrease due to decomposition of organic matter such as acidic leaves

Answer 215

the ability of the soil to retain water. The potential changes as soil texture changes

Answer 216

may change from full sunlight, to shady, to darkness as trees become established

Answer 217

increases with population growth, and may be unsuitable to certain species

Answer 218

these are the plants and animals that are the first to colonize a newly exposed habitat. Pioneer species are usually opportunistic, r-selected species that can tolerate harsh conditions Lichens and mosses are examples of pioneer species because they grow fast and produce many progeny rapidly As soil, water, and light changes, r- selected species will be replaced by stable k-selected species. The k- selected species live longer, so their environmental effects slow down the rate of succession and reach climax where it remains for hundreds of years

Answer 219

occurs on substrates that have never previously supported living things, such as volcanic islands, lava flows, or rock left behind by retreating glaciers. One of the essential prowesses for primary succession is soil building. Example - Primary succession could occur on rock or lava. First, lichens establish themselves and hold moisture and secrete acids to erode rock into soil. Soil then accumulates, and bacteria, protists, mosses, and fungi all appear. Insects then start to appear. The new soil is nutrient deficient, so nitrogen- fixing bacteria appear early. Grasses, herbs, weeds (all r- selected species) then become established. Eventually, depending on climate conditions, r- selected species are replaced by k- selected species, which include species like perennial shrubs and trees

Answer 220

begins in habitats where communities were entirely or partially destroyed by damaging events, such as fire, flood, insect devastation, overgrazing, forest clearing, construction sites, etc. The habitat previously supported life, so unlike primary, secondary succession begins on substrates that already bear soil Examples: Secondary succession can occur on abandoned cropland. Germination of r- selected species occurs from seeds already in the soil. Later, trees will follow Ecological succession can happen with a pond. Note however, that this would only be secondary if there was a disruption of a pre-existing community. First, plants such as algae and pondweed and animals such as protozoa, insects, and fish colonize the pond. Next, plants such as reeds, cattails, and water lilies grow and make the pond shallower. As the pond becomes a moist marsh, grasses, herbs, shrubs, willow trees, frogs, and snakes start to exist at this habitat. Finally, the pond has become a woodland with trees as its climax species, such as pine or oak

Answer 221

the species in a community that is the most abundant or collectively has the highest biomass.

Answer 222

not usually abundant but exert a strong control on their community structure not by their high quantity, but through their pivotal ecological role.

Answer 223

a.k.a. foundation species, dramatically alter their physical environment.

Answer 224

sits at the top of the food chain and no other creatures predate it.

Answer 225

autotrophs that convert the sun’s energy into chemical energy. Primary producers include plants, photosynthetic protists, cyanobacteria, and chemosynthetic bacteria. Their efficiency from sunlight is only about 1% of the energy available to them

Answer 226

these are herbivores. They have long digestive tracts with greater surface area so there is more time for digestion. Symbiotic bacteria in the digestive tract breaks down the cellulose which the herbivore itself cannot digest. Primary consumers eat primary producers

Answer 227

these are primarily carnivores, and they eat primary consumers

Answer 228

they are secondary carnivores, and they eat secondary consumers

Answer 229

consumers that obtain energy by consuming detritus. Detritus is nonliving organic material. It can be the remains of dead organisms, but also can be feces, fallen leaves, or wood. Smallest detritivores are decomposers such as fungi and bacteria. Other detritivores include nematodes, earthworms, insects, scavengers (vultures, jackals, crab), and saprophytes

Answer 230

show the relationships between trophic levels, or biomass.

Answer 231

describes the proportion of energy represented at one trophic level that is transferred to the next. On average, an efficiency of about 10% is transferred to the next. 90% of the energy is lost to metabolism and to detritivores when they die. Energy/biomass/quantity is greatest at the primary producer level and lowest at the tertiary consumer level. Tertiary level is least stable and most sensitive to the population fluctuations from the lower levels. Because ecological efficiency is so low, domesticated animals used for work are herbivores at lower trophic levels. If carnivores were domesticated for work instead, the energy required to raise and sustain the animals would be greater than the animal’s value returned in food or work.

Answer 232

Do not confuse trophic efficiency with production efficiency (percentage of energy stored in assimilated food that is not used for respiration or excreted as feces). Birds and mammals have low product efficiency because they use lots of energy to maintain a constantly high body temperature. Fish, which are ectothermic, have higher production efficiencies, and insects and microorganisms are higher still.

Answer 233

linear flow chart of who’s eaten by whom.

Answer 234

an expanded, more complete version of a food chain showing major plants, animals that eat the plants, animals that eat the animals, detritivores, etc. The greater the number of pathways in a community food web, the more stable the community is.

Answer 235

major storage locations for essential elements.

Answer 236

the process through which elements are incorporated by terrestrial plants and animals.

Answer 237

process by which the element returns to the environment.

Answer 238

The reservoir are the oceans, air (water vapor), groundwater, and glaciers. Evaporation, wind, and precipitation moves water from the ocean to land. Assimilation is done by plants absorbing water from the soil, and by animals drinking and eating other organisms (which are mostly water). Release is done when plants transpire and when animals and plants decompose

Answer 239

carbon is required for building organic materials. It is the basis for photosynthesis and respiration. The reservoirs are atmospheric CO2, fossil fuels (coal, oil), peat, and durable organic matter (e.g. cellulose). Assimilation is done by plants when they use CO2 in photosynthesis, and by animals when they consume plants (this is carbon fixing because the carbon is reduced from its inorganic form of CO2 to organic compounds). Release of CO2 occurs through respiration, decomposition, and when organic material is burned

Answer 240

nitrogen is required for the manufacture of amino acids and nucleic acids. The reservoirs are atmospheric nitrogen (N2) and soil (NH4+, NH3, NO2, NO3). Assimilation occurs when plants absorb nitrogen as either NO3- or NH4+ and when animals obtain nitrogen by eating plants/ animals. Release of nitrogen is done by denitrifying bacteria, which convert nitrate into atmospheric nitrogen. Detritivorous bacteria also release nitrogen by converting organic compounds back to ammonium (ammonification). Animals release nitrogen by excreting ammonium, urea, or uric acid, and through decay since nitrogen in the form of ammonia (NH3) is released from dead tissues

Answer 241

This is when atmospheric nitrogen (N2) is converted into organic nitrogen (NH4+) through nitrogen-fixing bacteria in the soil. Nitrogen can also be fixed by lightning and be converted into nitrogen oxides (NOx)

Answer 242

This is when ammonium (NH4+) is converted to nitrite (NO2-) followed by the conversion of nitrite to nitrate (NO3-) by nitrifying bacteria

Answer 243

Phosphorus is required for manufacturing ATP and all nucleic acids. Cycles for other minerals such as calcium and magnesium are similar to the phosphorous cycle. The reservoirs for phosphorous are rocks and ocean sediments because erosion transfers phosphorous to the water and soil. Assimilation occurs when plants absorb inorganic phosphate (PO43-) from the soil and when animals obtain organic phosphorus when they eat. Release of phosphorous occurs when plants and animals decompose, and when animals excrete phosphorous in waste products

Answer 244

has a high, but stable temperature and humidity. There is heavy rainfall. The biome is filled with tall trees with branches at the tops that allow little light to enter. This is the most diverse biome. Epiphytes can be found in this biome, which are plants that grow commensally on other plants, like vines

Answer 245

these are tropical grasslands with scattered trees. Savannas are similar to the tropics in that they both have high temperatures, but savannas get very little rainfall (~25 inches a year to prevent the regions from turning into deserts). In the African savanna, you can find ungulates, which are large-hooved plant-eating mammals like giraffes. Savannas are also subject to seasonal droughts and fires. Savannas cover many tropical and subtropical parts of Australia and Africa

Answer 246

this biome receives less water with uneven seasonal occurrences of rainfall. Temperate grasslands are subject to lower temperatures than savannas (e.g. north American prairie). Grassland soils are among the most fertile in the world. Seasonal droughts, fires, and large mammals grazing can be seen here

Answer 247

these forests have warm summers, cold winters, and moderate precipitation. Large deciduous trees shed leaves during winter, and the soil is rich due to leaf shed. There is vertical stratification in this biome: different types of plants and animals live depending on the strata, or “layer”, of the forest. Principal mammals hibernate through cold winters

Answer 248

these forests are cold and sometimes dry. Vegetation has evolved adaptations to conserve water, such as needle leaves. Some temperate coniferous forests are not dry and receive precipitation via rainfall. These forests are cold, but warmer than taigas

Answer 249

are hot and dry and has the most extreme temperature fluctuations of hot days and cold nights. The growth of annual plants is limited to a short period following rare rain. Plants and animals adapt to conserve as much water as possible, such as urinating infrequently, cacti spines, etc.

Answer 250

this biome is south of the tundra. Taigas are coniferous forests filled with trees like spruce, fir, and pine. Taigas have very long, cold winters and low precipitation in the form of heavy snow. This is the largest terrestrial biome

Answer 251

this biome has cold winters where the ground freezes. The top layer thaws during summer to support minimal vegetation, such as moss, lichen, low growing shrubs, grasses, but no trees. The deeper soil (permafrost) remains permanently frozen. There is very little rainfall, and it cannot penetrate the frozen ground. Tundras have short growing seasons

Answer 252

this terrestrial biome along the California coastline is characterized by wet winters, dry summers, and scattered vegetation (dense, spiny shrubs). California fires happen here

Answer 253

frozen with no vegetation or terrestrial animals.

Answer 254

cover over 75% of the Earth’s surface.

Answer 255

ponds, lakes, streams, and rivers. Fresh water biomes are hypotonic to organisms, and the biome is affected by climate and weather variations

Answer 256

the largest biome covering 3⁄4 of the world surface. Marine biomes provide most of the earth’s food and oxygen. These biomes include estuaries (where oceans and rivers meet), intertidal zones (where ocean meets land), continental shelves/ littoral zones (shallow oceans bordering continents), coral reefs, and pelagic oceans (open ocean) Marine biomes have a relatively constant temperature because of water’s high heat capacity and volume. The amount of nutrient materials and dissolved salts are also relatively constant. Marine biomes are divided into regions classified by the amount of sunlight received, distance from the shore, depth, and open water vs. ocean bottom. There are two major divisions to the marine biome: i. Benthic zone ii. Pelagic zone

Answer 257

this is the lowest layer of a body of water, including the sediment surface and sub- surface layers. In deep ocean water, light does not penetrate. Most organisms here are scavengers and detritivores. The benthic zone can be aphotic or photic depending on the depth

Answer 258

the water that is neither close to shore nor close to the very bottom. This zone is broken down from top to bottom in layers: (i) Epiplagic (ii) Mesoplagic (iii) Bathypelagic (iv) Abyssopelagic (v) Hadopelagic

Answer 259

this is the surface layer of water and the only photic zone since there is enough light for penetration. Nearly all primary production of the ocean occurs here

Answer 260

an aphotic zone, so there is not enough light for photosynthesis. There is minimal oxygen here

Answer 261

aphotic zone and pitch black. There is no plant life, and most organisms here consume detritus that comes down from above

Answer 262

aphotic zone. It is cold, high pressure, and most species have no eyes due to the lack of light

Answer 263

most life here exists in hydrothermal vents. This zone is aphotic

Answer 264

there are pelagic/benthic zones in both marine and freshwater biomes.

Answer 265

In winter and summer, lakes are stratified by temperature. The upper layer is heated more by the sun. Because warmer water is less dense, it floats at the top. The warm and cold water is generally unable to mix in the summer. Oxygen concentration decreases with depth, and the bottom layer is high in nutrients. In autumn and spring, the warm, oxygenated water layer cools down and sinks to the bottom. The sinking water pushes up the old bottom layer, and so nutrients from the bottom go to the top. This process is known as turnover.

Answer 266

the burning of fossil fuels, deforestation, factory emissions, cars, etc., increases CO2 in the atmosphere. This causes more heat to be trapped and increases the greenhouse effect. Normally, the greenhouse effect is a good thing for maintaining heat on Earth, but the large increase of CO2 emissions is overkill for the greenhouse effect. Thus, global temperature rises, which raises the sea level by melting ice. Agriculture output is also decreased by affected weather patterns. Greenhouse gases include methane, CO2, ozone, CFC’s, which all cause heat to build up in the lower atmospheres.

Answer 267

O3 is ozone, which absorbs UV radiation. This prevents excess UV from reaching the surface of the earth. CFCs (chlorofluorocarbons) enter the upper atmosphere and break down O3. Normally, ozone quickly reforms as it is split by sunlight. Formation of the ozone layer allowed land colonization since organisms no longer needed water to shield them from damaging UV rays.

Answer 268

the burning of fossil fuels (e.g. coal) releases SO2 and NO2 into the air. When these compounds react with water vapor, sulfuric acid and nitric acid (H2SO4 and HNO3) is created. This acid then rains back down on earth and can kill plants and animals.

Answer 269

overgrazing of grasslands that border deserts transforms the grasslands into deserts. Agricultural output decreases, or habitats available to native species are lost.

Answer 270

the clear-cutting of forests causes erosion, flooding, and changes in weather patterns. Additionally, the slash and burn method of clearing tropical rain forests increases CO2, which increases the greenhouse effect. Nutrients in the soil are destroyed as well.

Answer 271

air, water, and land pollution contaminate materials essential to life. Many pollutants remain in the environment for decades Eutrophication is the process of nutrient enrichment in lakes, which causes subsequent increases in biomass. Lakes polluted with fertilizer runoff have abundant nutrients, especially phosphates. This stimulates algal blooms, which are massive algae/ phytoplankton patches of growth. These blooms respire and deplete oxygen. When the blooms breakdown, detritivorous bacteria deplete even more oxygen. Thus, many animals die of oxygen starvation, and the lakes fill with carcasses of dead animals and plants. Note that phytoplankton does photosynthesis, but at night they reduce oxygen when they respire, and the detritivores continue to multiply as organisms die. This further decreases O2. Phytoplankton are autotrophic organisms that float near the surface of oceans, lakes, and ponds. Eutrophication occurs naturally but human influence accelerates it, leading to an imbalance. Critical load is the amount of added nutrient, usually nitrogen or phosphorous, that can be absorbed by plants without damaging the ecosystem integrity. When the critical load is exceeded, the runoff overwhelms and leaches into other ecosystems, creating the above problem.

Answer 272

this is a result of human activities, especially with regards to the destruction of their habitats.

Answer 273

new species can be moved intentionally or accidentally by humans. This can disrupt a new community because the invasive species preys on native organisms. The invasive species can outcompete native organisms for resources as well. For example, when killer honeybees were introduced, they stung and killed people. Another invasive species, zebra mussels, outcompeted original residents.

Answer 274

pesticides are effective but are dangerous to humans. Biological control alternatives are safer. These alternatives include crop rotation, natural enemies, or insect birth control.

Answer 275

as one organism eats another, toxins (e.g. pesticide) become more concentrated at each higher trophic level. This is biological magnification. Toxins include antibiotics, hormones, carcinogens, teratogens (causes birth defects), which can all get into the food chain and cause biomagnification.

Answer 276

using organisms to detoxify a polluted ecosystem.

Answer 277

using organisms to add essential materials to a degraded ecosystem.

Answer 278

Biodiversity has three levels. Endangered species is in danger of extinction Threatened species are considered likely to become endangered soon. A biological hotspot is a small area with numerous endemic species and a large number of endangered and threatened species.

Answer 279

a small population size leads to inbreeding, and genetic drift has a significant effect. The loss of genetic variability leads to reduced fitness and lower survivability. To avoid this situation, a population must sustain itself at the minimum viable population. If the populations drops too low, it can cause an extinction vortex.

Answer 280

events (e.g. storm, flood, drought, human activity) that change communities by removing organisms or altering resource availability.

Answer 281

human activities lead to increases of acidity in the ocean. Edges are boundaries between ecosystems. Human alterations can increase edges, which have reduced biodiversity overall, and create imbalances that favor edge-adapted species. This leads to fragmentation. In fragmented habitats, movement corridors (small habitat clumps/strips connecting otherwise isolated patches) are important for conserving biodiversity. Movement corridors can be created artificially, such as bridge tunnels that let animals cross without getting hit by cars.

Answer 282

suggests that low to moderate levels of disturbances actually increase species diversity, while high levels of disturbances reduce diversity.

Answer 283

translocation of a species to a favorable habitat beyond its native range to protect it from human-caused threats.

Answer 284

these are areas of dry land that form on the leeward side (downwind) of a high mountain. Rain clouds approach a mountain range and thus rise in elevation. The surrounding air becomes cooler, and the dew point is eventually reached. The dew point is the temperature that air must be cooled at to become saturated with water vapor. When the air is further cooled, water vapor will condense to form dew (liquid water). After the dew point is reached, precipitation occurs as the clouds gain precipitation and continue to rain towards the peak of the mountain. As the clouds begin to descend down the leeward side of the mountain, there is a decrease in elevation and an increase in air temperature. Precipitation decreases and causes a dry rain shadow (desert biome). Rain shadows can occur in the high mountains of Europe and even the Andes of South America

Feralis Ch 6 Flashcards

(309 cards)