bio 182 exam 2
a plant should invest more energy in tap roots and less energy in seeds when the probability of being eaten by an animal increases
false
african pygmies are likely to reproduce earlier because they lack sufficient food to continue growing
false
during the day the primary cost of thermoregulation for this camel was a loss of energy to produce heat
false
during the time that subpopulation lived in puddles they would have been considered sympatric
false
fish with hb2 can bind more oxygen than fish with the hb1 in both cool and warm waters
false
fish with hb2 likely occur in warmer waters than fish with hb1
false
if a mutation occurred causing the daughter-in-law of two pygmies to grow taller than usual this daughter would likely reproduce at even earlier age than her parents did
false
in the absence of mutation the heritability of neck length in a population of giraffes would remain the same
false
in warm water a fish with hb1 could not perform as many reactions requiring oxygen as could a fish with hb2
false
on a cold night, less flexible cell membranes will function better than more flexible ones
false
over many generations the average length of necks in a giraffe population will increase indefinitely
false
the DNA sequence of a billy is likely to be most similar to the DNA sequence of a brush possum
false
the camel stopped being an endotherm and started being an ectotherm when it allowed its body temp to rise
false
the cell membrane of fruit flies changes in composition throughout the day to enable flies to maintain a constant body temp
false
the hair of placental mammals and the hair of marsupial mammals are more likely to an example of homoplasy than homology
false
the optimal strategy would be to invest as much energy as possible in roots that explore a single patch of soil
false
the population of giraffes the average length of the neck is under directional selection
false
when the pong reforms each puddle would be considered different biological species
false
a fly can alter the composition of phospholipids in its cell membranes as fast as or faster than the air temp changes during the day
true
a heterozygous fish can simultaneously expresses hb1 and hb2 alleles would pay an energetic cost to bind oxygen well in cold and warm waters
true
according to this phylogeny the billy is most closely related to the devil
true
african pygmies are likely to live in risky environments where the probability of survival is low compared to other environments where humans live
true
although both virginia opossums and gray squirrels live in the united states opossums are more closely related to kangaroos
true
by allowing its temp to rise the camel reduced its rate of heating from convection
true
by allowing its temp to rise the camel saved water that otherwise would have been used to thermoregulate
true
during the afternoon the camel balanced the warming form radiation by cooling through evaporation
true
if flies were collected and immediately tested at a high temp a fly collected during the day would probably fly better than one collected during the night
true
if the cost of building a tap root increases a plant should increase the number of fine roots on each tap root
true
natural selection would reduce the variation in neck length in a population of giraffes
true
pygmies likely evolved because individuals who reproduced early in life were more fit than individuals who reproduced later in life
true
the bh2 protein may be on average more flexible than the hb1 protein
true
the change in the structure of the membrane is likely a case of adaptive plasticity
true
the marsupium of a kangaroo and the marsupium of an antechinus are more likely to an example of homology than homoplasy
true
the optimal strategy maximized the water gained per unit of energy invested in roots
true
the relationship between a giraffes neck length and its fitness would be better described by a quadratic equation than a linear equation
true
this model depicts an energetic cost of producing roots and an energetic benefit of having water for photosynthesis of evaporative cooling
true
when a pond reforms natural selection would favor prezygotic isolating mechanisms that reinforce any postyzygotic isolating mechanisms
true
when the pond reforms the rotifers from each puddle could be considered different evolutionary species
true
while in separate puddles, genetic drift could cause the evolution of reproductive solution in rotifers
true
While walking in the desert, a well-hydrated camel was exposed to intense solar radiation and hot surroundings. During the morning, its body temperature rose steadily by 6°C. In the afternoon, however, the camel opened its mouth and breathed heavily until the sun fell below the horizon. 1. during the day the primary cost of thermoregulation for this camel was a loss of energy to produce heat 2. by allowing its temp to rise, the camel seed water that otherwise would have been used to thermoregulate 3. by allowing its temperature to rise the camel reduced its rate of heating form convection 4. during the afternoon the camel balanced the warming form radiation by cooling through evaporation 5. the camel stopped being an endotherm and started being an ectotherm when it allowed its body temp to rise
1. false- 2. true 3. true 4. true 5. false
Giraffes are the tallest animals on land. An adult giraffe has a neck that exceeds 2 m in length. This neck enables a giraffe to access food that other animals cannot reach and detect predators from a long distance. Studies have shown that giraffes will browse trees at heights that other herbivores cannot reach. The water and nutrients gained from leaves enhance a giraffe's fitness by increasing survival and reproduction. However, a long neck comes with a cost: the heart must spend more energy to pump blood to the brain. If a giraffe's neck were too long, the energy required to circulate blood would exceed the energy gained from eating leaves 1. in a population of giraffes the average length of the neck is under directional selection 2. Over many generations the average length of necks in a giraffe population will increase indefinitley. 3. the relationship between a giraffes neck length and its fitness would be better described by a quadratic equation than a linear equation 4. natural selection would reduce the variation in neck length in a population of giraffes 5. In the absence of mutation the heritability of neck length in a population of giraffes would remain the same.
1. false- a very short neck limits feeding but a very long neck increases the energy needed for circulation 2. false- selection against very long necks will occur as the energy required for circulation exceeds the energy gained by eating leaves on tall trees 3. true- the relationship is likely hump-shaped which is better described by a quadratic equation 4. true- stabilizing selection reduced the variance of a trait by favoring intermediate lengths over extreme lengths 5. false- heritability decreases over generations as natural selection involves some genotypes reproducing less than others
Fishy proteins Cod fish have two alleles for a protein that binds oxygen, called the Hb-1 and Hb-2 alleles. Fish expressing the Hb-1 allele are found in different environments than fish expressing the Hb-2 allele. Upon bringing both groups of fish into a lab, scientists found that the Hb-1 and Hb-2 proteins function differently when tested under two different temperature treatments, cold and warm temperature. The groups of fish were similar in size, age, and sex ratios. The figure below shows the findings from the scientist's research. Figure 1. The oxygen-binding performance of a protein depends on which allele codes for the protein (Hb-1 or Hb-2). The x-axis indicates the temperatures at which the protein was tested. The y-axis indicates the amount of oxygen bound to either the Hb-1 or Hb-2 protein. 1. Fish with Hb-2 can bind more oxygen than fish with the Hb-1 in both cool and warm waters 2. the Hb-2 protein may be on average more flexible than the Hb-1 protein 3. In warm water, a fish with Hb-1 could not perform as many reactions requiring oxygen as could a fish with Hb-2. 4. Fish with Hb-2 likely occur in warmer waters than fish with Hb-1 5. A heterozygous fish that simultaneously expressed Hb1 and Hb2 alleles would pay an energetic cost to bind oxygen well in cold and warm waters
1. false- fish with hb2 can bind more oxygen than fish with the hb1 only in cool water 2. true- to perform better at a low temp a protein must be intrinsically more flexible 3. false- a fish with hb1 would actually bind more oxygen in warm water than a fish with hb2 would 4. false- fish with hb2 are poly adapted to warm water compared to fish with hb1 5. true- to produce both forms of the protein a fish would need to spend twice as much energy
During the summer, a small pond loses water to evaporation. Eventually, this pond becomes a series of puddles separated from one another by at least several meters. Most animals disperse or die as the pond dries, but some microbes still remain in the puddles. Each of these species used to live in the pond as a much larger population, but are now subpopulations that reside in the puddles. Some of the microscopic species with short generations are bacteria, paramecia, and rotifers. All of these species reproduce asexually, except for one species of rotifer that reproduces sexually. The puddles remain separated until the following spring, when abundant rain causes them to expand and form a pond like the one from last year 1. during the time that subpopulation lived in puddles they would have been considered sympatric 2. when in separate puddles, genetic drift could cause the evolution of reproductive isolation in rotifers 3. When the pond reforms the rotifers from each puddle could be considered different evolutionary species 4. When the pond reforms the bacteria from each puddle would be considered different biological species. 5. when the pong reforms natural selection would be favor prezygotic isolation mechanisms that reinforce any ostzygotic isolating mechanisms
1. false- population that live in different spaces are considered allopatric not sympatric 2. true- although unlikely for such a short period genetic drift in the small populations could produce traits that isolate them 3. true- they could have evolved by selection and drift in the period of geographic isolation 4. false- bacteria are asexual and thus cannot be biological species. 5. true- natural selection reinforces post-zygotic isolation mechanisms with pre-zygotic ones
In certain populations, people grow to a much smaller size than people do in other populations. For example, African pygmies are essentially miniature humans, with all the same proportions of other Africans except for their short stature (Fig. 1). Researchers discovered that pygmies begin to reproduce at a younger age than humans of normal stature do. Prior to reproduction, pygmies grow about as fast as people in other populations do. 1. african pygmies are likely reproduce earlier bc they lack sufficient food to continue growing 2. Pygmies likely evolved because individuals who reproduced early in life were more fit than individuals who reproduced later in lif 3. african pygmies are likely to live in risky environments where the probability of survival is low compared to other environments where humans live 4. if mutation occurred causing the daughter of two pygmies to grow taller than usual this daughter-in-law would likely reproduce at an even earlier age than her parents did 5. if a pygmy were to mate with an african of normal size the offspring would likely be intermediate in size
1. false-pygmies grow as fast as other humans and must have energy to continue growing if they are abel to reproduce instead of grow 2. true- small size at maturity results when individuals grow slower or reproduce earlier, since pygmies don't grow much slower than normal, their size must reflect selection or earlier reproduction 3. true- low survival favors the evolution of early reproduction at a smaller size 4. false- allocating more energy to growth early in life would reproduce the energy available to reproduce causing the daughter to mature at a later age 5. true
Plants use roots to search for water in patches of soil. A certain amount of energy must be spent to build a tap root that spreads from the base of the plant to the patch of soil. After that, additional energy can be used to make fine roots that explore the patch and extract water. Whatever energy the plant does not spend on roots, it can invest in reproductive structures such as flowers and fruits. The graph below shows the relationship between the energy invested in roots and the water extracted from each patch of soil. 1. the optimal strategy maximizes the water gained per unit of energy invested in roots. 2. the optimal strategy would be to invest as much energy as possible in roots that explore a single patch of soil 3. if the cost of building a tap root increases, the plant should increase the number of fine roots on each tap root 4. this model depicts an energetic cost of producing roots nd an energetic benefit of having water for photosynthesis or evaporative cooling 5. a plant should invest more energy in tap roots and less energy in seeds when the probability of being eaten by an animal increases
1. true 2. false 3. true 4. true 5. false
Cell membranes balance the need to remain intact with the need to move during function. Researchers studying fruit flies discovered that the cell membranes of these ectothermic animals changed throughout the day. During the night, when the environment was cool, the membranes were composed of mostly unsaturatedphospholipids, leading to a very flexible structure. During the day, when the environment was warm, the membranes were composed of mostly saturatedphospholipids, leading to a less flexible structure. 1. the change in the structure of the membrane is likely a case of adaptive plasticity 2. the cell membrane fo fruit flies changes in composition throughout the day to enable flies to maintain a constant body temperature 3. on a cold night less flexible cell membranes will function better than more flexible ones 4. a fly can alter the composition of phospholipids in its cell membranes as fast as or faster than the air temperature changes during the day 5. if flies were collected and immediately tested at a high temperature a fly collected during the day would probably fly better than one collected during the night
1. true- the change in the phenotype is likely to enhance cellular function and hence potentially enhance fitness 2. false- a fly is an ectotherm which means its body temp changes with air temp 3. false- more flexible membranes would be needed to overcome the low kinetic energy of the cold 4. true- for acclimation to confer a benefit, it must occur more rapidly than the rate of environmental change 5. true- a fly collected during ht day would have a cell membrane acclimated to high temp
Marsupials are group of mammals whose ancestors diverged from other mammals more than 150 million years ago. As with all mammals, placental mammals have hair that conserves heat and mammary glands that produce milk. However, unlike other mammals, the marsupials give birth to tiny babies that must complete development inside a special pouch, called a marsupium. Placental mammals give birth to large babies that completed development inside a uterus while being nourished by a placenta. Most of the living marsupials occur in Australia or South America. Only one species of marsupial—the Virginia opossum—occurs in North America, with many placental mammals, such as squirrels, cats, and bears. The evolutionary relationships among some Australian marsupials and the placental mammals are shown below. 1. according to this phylogeny the billy is most closely related to the devil 2. the DNA sequence of a billy is likely to be most similar to the DNA sequence of a brush possum 3. although both virginia opossums and gray squirrels live in the united states opossums are more closely related to kangaroos 4. the hair of placental mammals and the hair of marsupial mammals are more likely to an example of homoplasy than homology 5. the marsupium of a kangaroo and the marsupium of an antechinus are more likely to an example of homology than homoplasy
1. true- the sister taxon of the devil is the billy meaning that they share the most recent common ancestor 2. false- the sister taxon of a billy is the devil the opossum is distantly related which would imply its DNA sequence differs more 3. true- the opossum is a marsupial whereas the gray squirrel is a placental mammal 4. false- the more parsimonious explanation would be that marsupial mammals and placental mammals inherited hair from a common ancestor 5. true- the more parisominous explanation would be that all marsupials inherited a marsupium from a common ancestor
