TOEFL Speaking Practice Test

Through the lecture, the professor explains how the advent of photography helped to advance the world of painting. He is able to demonstrate his point through two key examples. In the first example, he explains that photography in many ways supplanted painting as the main way to capture an event. This forced painters to turn towards new modes of painting that were not realistic, and in turn created the various “isms” of the twentieth century in which painters made more abstract images. The second change photography created was through its use as a tool for learning. By photographing a seldom seen image, such as a horse rearing, painters could then use the still shot of such an act as a tool for learning how to paint that more perfectly. In these ways, painters and the art of painting, in general, have grown and changed because of the very different ways that photography inadvertently affected the painting.

The lecturer introduces two ways to deal with soil erosion. The first way he discusses is crop rotation, in which different types of crops are planted in an area year after year. Crop rotation allows important nutrients to remain in the soil, because changing the types of crops planted prevents one particular crop from using up nutrients over a long period of time. The other technique discussed is called contour plowing, which is farming following the elevation contour lines of a slope. Contour plowing is beneficial because it allows water to move more easily, rather than forming into rifts. Another benefit mentioned about contour farming is that it helps water to settle into the topsoil, which in turn acts against erosion and flooding.

The lecturer discusses two benefits of the domestication of animals. The first benefit that domesticated animals provide is a constant source of food. Unlike hunting, which is unreliable, animal domestication allows humans the opportunity to have meat, and move herds of animals to different places over time. Some animals such as sheep also contribute to agriculture by clearing the land of grass and weeds when they eat. The second way that domesticated animals are helpful is that they allow people to make useful products. For example, the lecture notes that animals like goats and cows not only provide milk, but also skin and hair, used to make containers and traditional parchment.

In this lecture, the professor uses two theories to hypothesize that the pterosaurs were actually not able to fly by flapping their wings. The first theory is that the pterosaurs were probably cold-blooded and animals that are cold-blooded aren’t able to produce a lot of energy. The pterosaurs would need to use a lot of energy for their big wings. The second theory is that the pterosaurs would need to take off, by the ground and their legs wouldn’t have been powerful enough to do so. Due to the fossils that were found it was unlikely that their muscles would’ve helped them jump or run to take flight. Therefore, pterosaurs wouldn’t have been able to fly, no matter how big their wings were. So these are two major theories about why pterosaurs were not capable of really flying. p

The lecture is about the belief that some paleontologists have that bees could have existed as long as 200 million years ago. This theory is supported by fossil structures that resemble bee nests. But some people who don’t believe this offer two reasons why the fossil structures are not bee nests. The first reason is that today’s bees use flowers to feed off of. That’s how we get pollination. Yet, 200 million years ago there was an absence of flowers and that’s one reason bees could not exist. The second reason is that the fossilized structures found in Arizona prove that the nests actually resemble modern bees.
One evidence is that modern bee nests’ chambers have caps featuring a spiral pattern, whereas the fossilized chambers lack such caps. So those two reasons give speculation as to why bees could not have existed 200 million years ago.

The lecture is about the belief that some paleontologists have that bees could have existed as long as 200 million years ago. This theory is supported by fossil structures that resemble bee nests. But some people who don’t believe this offer two reasons why the fossil structures are not bee nests. The first reason is that today’s bees use flowers to feed off of. That’s how we get pollination. Yet, 200 million years ago there was an absence of flowers and that’s one reason bees could not exist. The second reason is that the fossilized structures found in Arizona prove that the nests actually resemble modern bees.
One evidence is that modern bee nests’ chambers have caps featuring a spiral pattern, whereas the fossilized chambers lack such caps. So those two reasons give speculation as to why bees could not have existed 200 million years ago.

The professor talked about the two main reasons scientists believe it would be really difficult for humans to live on Venus and those same reasons could be said for Mars. Similar to Venus, although with a different atmosphere, it is going to be difficult for humans to consume as much sun as they do on Earth, since Mars is further away from the sun. The second reason is that although Venus has hardly any water vapor and has no reservoirs of water on its surface, Mars is believed to have at least some water. But Earth is made up of mostly water and the abundance makes it easier to have a regular supply of water, especially water enriched with minerals that humans are used to. This is unlike Mars which has a limited supply. Also, like Venus, but not nearly as far, traveling back and forth from Mars to Earth for supplies would be time consuming.

The lecture is about two examples of animal behaviors that exhibit ritualization. The professor says that ritualization is a behavior that can identify a certain animal, and the best ritualization examples are typically from the animal kingdom. There are two examples mentioned in this lecture. The first example of ritualization can be found in birds. The professor says that birds attract their mates by engaging courtship rituals. And these courtship rituals include behaviors such as dancing, singing songs, and decorating their nests. The second example of ritualization can be seen in dogs. He says that dogs communicate with other dogs by raising their lips and growling in order to defend their territories. So these are two examples of animals engaging in ritualization as a way to identify themselves to their own species as well as to communicate with others.

Parasitism is the relationship between a parasite and a host. The parasite sometimes does harm to a host, but it will never kill the host because it feeds on the host or the host’s nutrients for survival. The example given by the professor was about a mistletoe plant that lives on the surface of a tree. It uses the tree’s water and nutrients to help itself grow, and therefore doing harm to the tree, but never kills it. The other example used by the professor was about fleas on a dog. Fleas live on the surface of their host and survive by drinking the blood of their host, in this case, a dog. Fleas also do harm to their host, blood loss, but also inject a poison, like mosquitoes, that causes invariable itching. In both examples, the parasite lived on the surface of their host and required that the host stay alive.

Camouflage is used as a defense mechanism by some sea creatures. The two examples used in the lecture were, the leafy sea dragon and the cuttlefish. Although both these creatures use their genetically inherited gift to escape from predators by blending in with their environment, they do it differently. The leafy sea dragon blends in with the seaweed and kelp in its environment using its leaf-like body, while the cuttlefish blends in with the light in its environment using the special pigments under its skin. Ultimately, both creatures use camouflage for protection, however, both have a different way of camouflaging itself.

The lecturer explains how two animals survive in environments without much light.

To begin with, she describes how the spookfish uses tube-shaped eyes to hunt its prey. She notes that it lives in almost total darkness. However, its eyes always point upwards, so it can spot the faint outlines of fish swimming above it. When this happens, it quickly swims upwards to catch and eat the fish. Its eyes are quite large, so it is able to notice even very small prey.

Second, she describes how the lanternfish is able to produce its own light to both catch prey and escape from predators. She says that it has tiny organs throughout its body that produce light through a chemical reaction called bioluminescence. As a result, it can attract the attention of other fish, which it eats. In addition, it uses the light for protection. By matching the intensity of light sources above it, it can disguise itself from potential predators.

A biological clock is internally embedded in all organisms. It controls organism’s rhythms to nature, like waking up and sleeping. The professor used two examples to demonstrate how a biological clock works. The first example used was about a squirrel. Scientists performed an experiment where they kept a squirrel in darkness for a certain amount of time to monitor the squirrel’s behaviors. Each day, the squirrel’s activities deferred by 21 minutes, thus showing that the squirrel’s biological clock was shifting in accordance to the constant darkness. The second example used was about humans. Humans are inadvertently changing their biological clocks, with light blocking objects like black curtains. The black curtains block the normal light exposure and therefore cause the biological clock to adjust. Both examples demonstrate that organisms have a biological clock that is affected by light exposure.

The lecture described how a desert frog survives in hot, dry climates. The professor explained two evolutionary adaptations that the desert frog uses to survive. The first adaptation is a highly flexible bladder. A desert frog’s bladder can store a large quantity of water. During a drought, the frog has the ability to release water slowly from its bladder to stay hydrated and survive. The second adaptation is a fatty layer underneath the skin. This fatty layer can also store water, but its main purpose is to reduce water evaporation to extend the frog’s water supply even further. Therefore, a desert frog can subsist on water for an extended period using two unique evolutionary adaptations in a highly flexible bladder and an extra fatty layer underneath its skin.

In the lecture, the professor explains the difference between queen ants and other social ants, specifically worker ants. He provides two examples to illustrate the phenomenon of having differently sized ants with drastically different roles in ant society. The first example is that queen ants are solely responsible for producing offspring. They are the only ants that can reproduce, so they spend their whole life laying eggs, whereas the worker ants will spend their lives foraging for food and caring for the offspring. Another example of the differences between these two groups and types of ants is in their varying physical looks. To begin with, queen ants are much bigger, have wings, and have stripes on their abdomen. Worker ants are much smaller, about half the size, and are a dark black color with no wings. So both the look and role of queen ants and worker ants are quite different across the ant community.

The professor uses two examples to explain coevolution. The first example is regarding honeybirds and bird-pollinated plants. The professor explains that honeybirds and these bird-pollinated plants have a mutualistic relationship. For honeybirds, they benefit from this relationship because they can feed on the plants’ nectar. For the plants, they benefit from this relationship because as honeybirds feed on their nectar, honeybirds carry their pollen to other flowers. In other words, these plants are pollinated by honeybirds.

Okay! The second example is regarding Acacia ants and Acacia trees. The professor explains that the ants protect the trees by fighting off intruding organisms like other insects and plants, while the trees provide a home and food for the ants.

Ultimately, the professor uses these two examples to explain coevolution.

In the lecture, the professor describes the natural phenomenon of molting, by which an animal casts off part of its body at a specific time of year. He explains that there are two different reasons why this happens to animals. First of all, some animals molt because of weather changes. He describes how mountain hares will grow short light coats of hair for the summer months, but then at the beginning of winter will molt their hair in exchange for growing a long thick coat of hair to survive the winter. In a second example, some animals molt to protect themselves from predators. North American weasels grow a brown fur coat in the summer to blend in with their surrounding. Then, in winter they molt and grow a white coat to blend in with the snow, and protect themselves from predators. Thus the professor provides two different explanations and examples for why animals undergo the phenomenon of molting.

In the lecture, the professor explains the phenomenon of animal congregation, which is when animals gather together in certain harsh environments as a way to survive. He offers two examples of different animals that use this process to survive. The first example is the penguins of Antarctica. During the breeding season, they are forced into the interior of the continent where the temperatures are dangerously low, so they congregate to block out the winds and produce communal heat. Another example he offers is the various animals that survive in herds. Many of these animals are African and will travel and gather in herds to help protect each other and fight off lions and leopards. He even gave the example of muskoxen circling up and pointing their horns outward to deter predators. While these two different approaches to congregating are quite different, they are also similar in that they are a way to help protect and survive.

The lecture is about how fish navigate with poor eyesight. Fish have reductive eyesight so they navigate their homes or territory in a way that is reduced. So naturally fish with poor vision use the lateral line. The lateral line consists of receptors called neuromasts. Using this, they can detect water pressure, currents, and objects. Naturally, some of these have this technique more developed than others. Secondly. the other way that fish navigate their environment is through electric currents through their bodies. They help other fish predict objects. This happens successfully. The fish are able to actually navigate the waters ahead because of this.

During the lecture, the professor explains some biological and behavioral adaptations that camels have to help them survive in the desert. He gives two examples, one biological and one behavioral, to explain their adaptations. The first example is a biological adaptation, the camel hump. Camels use their hump to store fatty tissue that can then be turned into water and food when they need it. It also helps to absorb heat and keep camels cool. The second adaptation is the camels’ inactive state. Whenever possible, camels lay down and don’t move in order to preserve their energy and resources. They also will often lay in groups to create as much shaded space and cast shadows over parts of each other’s bodies, keeping them cool and rested. So, through both biological and behavioral adaptations, camels have been able to change to fit their environment and better survive in harsh deserts.

During this lecture, the professor explains two physiological features which make birds different from other mammals, enabling them to migrate. He offers two reasons to explain this natural phenomenon. The first are birds’ respiratory systems. Rather than just breathing in and out like other mammals, birds breathe through their lungs into an air sac, and then back out through their lungs. This allows them to breathe a greater volume of air and to exchange the air twice, gathering more oxygen. In this way, they can survive at such high altitudes. Secondly, they have different chest muscles. Their chest muscles have the ability to store energy over long periods of time so that when they should be getting tired after hours of long-distance flight, they can tap into the reserves of energy in their chest muscles and continue flying until they reach their destination. In these two ways, birds are uniquely built for the process of migration by means of flight.

In this lecture, the professor explains the unique role that earthworms play in the environment, especially in generating good soil. The professor explains their role through two examples. First, worms eat organic waste from plants and turn that into a form that can then be reused by those plants for fuel and energy. The waste left by the worms is rich in minerals and helps to retain moisture, two things that are extremely helpful to plants. Secondly, worms are helpful through their ability to make tunnels. By creating tunnels as they travel underground, worms create a network of openings that allow water to travel further underground instead of just across the surface. These tunnels store water and provide additional sources to plants. So, through providing nutrients, space, and water to plants, worms have demonstrated their absolute usefulness to the plant kingdom.

In this lecture, the professor describes the reasons that insects have for generating sounds that carry messages to their same species. To prove this, the professor gives two reasons for why they produce sounds. The first reason that insects produce sounds is because they are attempting to alert each other to danger. Small insects that are unable to hunt for themselves produce noises to alert their parents to approaching predators. Once parents hear the sound they know to return and protect their young against predators. The second purpose for producing sounds is in search for food resources. For example, when a group of insects have exhausted their supply of leaves, they will make a noise to alert the entire group that they need to move on and find a new source of food. Similarly, when they find a new source of food, they will alert the entire group through making noises. So, in this way, insects utilize noises in order to help protect and provide for their species.

In this lecture, the professor describes the reasons that insects have for generating sounds that carry messages to their same species. To prove this, the professor gives two reasons for why they produce sounds. The first reason that insects produce sounds is because they are attempting to alert each other to danger. Small insects that are unable to hunt for themselves produce noises to alert their parents to approaching predators. Once parents hear the sound they know to return and protect their young against predators. The second purpose for producing sounds is in search for food resources. For example, when a group of insects have exhausted their supply of leaves, they will make a noise to alert the entire group that they need to move on and find a new source of food. Similarly, when they find a new source of food, they will alert the entire group through making noises. So, in this way, insects utilize noises in order to help protect and provide for their species.

In this lecture, the professor talks about two ways that the Arctic butterfly has adapted to its environment. The first adaptation he mentions is basking. When Arctic butterflies bask, they take in the sun’s warmth by opening their wings to direct sunlight. The heat from the sun is then circulated through their blood. Basking is important for the Arctic butterfly because its body temperature must at least 10 degrees celsius to fly. The other adaptation discussed is the Arctic butterfly’s ability to produce something called a cryoprotectant. Cryoprotectants act as a shield against the freezing of organic cells and tissues in very cold environments, such as the Arctic, and other Arctic animals also have this adaptation. So, basking and production of cryoprotectants are the two adaptations discussed in this lecture.

The professor discusses types of birds’ nests in the lecture, specifically ground nests and burrow nests. He first explains ground nests, in which birds lay their eggs directly on the ground. Some birds, like shorebirds and vultures may dig a pit before they lay their eggs. Other birds, like raptors and owls, will find a hidden place to lay their eggs, and do not scrape the ground to create a pit for their nests. The other nests which the professor mentions are burrow nests. Burrow nests are good for some birds, like puffins, because they provide protection and warmth for eggs and chicks. Sometimes birds make their own nests, and sometimes they reuse another animal’s burrow.

In this lecture, the professor explains the major negative impacts the deterioration of the ozone layer is having on our planet. He uses two different examples to help explain the large impact this single event is having. First of all, the hole in the ozone layer allows in large amounts of ultraviolet B radiation, something the professor says limits the reproduction of animals at the bottom of the food chain. If animals at the bottom of the chain are dying, then there is less food for animals higher up, which is bad for everyone. The second example he gave was that the hole allows in UV rays, which can be dangerous to humans in large amounts. They can lower the human immune system and make people susceptible to skin cancer. UV rays are also apparently bad for agriculture as well. So, through these two examples, the professor is able to explain the lasting negative effects of the hole in the ozone layer.

In the lecture, the professor explains how scientists went about proving that the Earth has geomagnetic poles. He demonstrates this discovery through various stages of understanding on part of the scientists. Despite scientists knowing that the earth is a magnet, they discovered the poles first through recognizing that when lava cools and becomes rock, the strongly magnetic particles in the rock line up along lines of force created by the magnetic field from the Earth’s poles. However, when faced with the discrepancy of why longstanding rocks had varying lines pointing towards the poles, it took scientists some time to discover and record the movement of Earth’s plates. Due to the constant movement of the plates over time, the rocks recorded varying positions of Earth’s geomagnetic poles, but only because of the shifting plates. So, through a series of unique discoveries were scientists able to discover the secrets of Earth’s magnetic poles and their long recorded life.

In this lecture, the professor explains the benefits to maintaining one of the most biologically diverse ecosystems in the world, wetlands. He explains their importance through three examples. First, they protect water quality for humans and animals by trapping sediments, like a filter, and retaining excess nutrients that end up in drinking water. Secondly, certain animals rely on the wetlands for either permanent or seasonal homes. Some animals use them as heavily protected breeding grounds, while others cannot survive elsewhere. Third, certain animals that help keep pollutants clear from other animals live in wetlands. Oysters survive off eating other things that are poisonous or dangerous to other animals. They also survive by living in coastal wetlands. Therefore, wetlands provide many unique qualities to a variety of animals and in this way the professor demonstrates their importance to the world.

The professor discusses how the Alpine plant lives in freezing temperatures. The professor gives two explanations as to how the Alpine plant has adapted to survive. The first explanation is a process that is called freezing-point depression. This is where the Alpine plant increases the amount of chemicals in their tissues. However, that method only works when it is moderately cold so the professor gives a second explanation. In the second explanation, the professor says that when the Alpine plant moves their water into intercellular space, after they dehydrate their cells. Ultimately the professor says that even if these two strategies fail, the Alpine plants have a backup plan. They can always repair or replace their damaged tissues.

The professor discusses how the Alpine plant lives in freezing temperatures. The professor gives two explanations as to how the Alpine plant has adapted to survive. The first explanation is a process that is called freezing-point depression. This is where the Alpine plant increases the amount of chemicals in their tissues. However, that method only works when it is moderately cold so the professor gives a second explanation. In the second explanation, the professor says that when the Alpine plant moves their water into intercellular space, after they dehydrate their cells. Ultimately the professor says that even if these two strategies fail, the Alpine plants have a backup plan. They can always repair or replace their damaged tissues.

The lecture is about a concept in biology called ecological succession. This is where natural species are established and replaced over a period of time. The professor says that there are two examples of this process; primary ecological succession and secondary ecological succession. The primary ecological succession happens in an area that was empty of life originally. For example, an area that is covered by lava. The secondary ecological succession is more common because it happens in an area that once had life. For example, a place that has been destroyed by wildfire like the rainforest. In summary, the reason that the secondary ecological succession is more common, not to mention quicker, is because having an area of land that already has soil that is rich with nutrients, is easier to be recolonized quicker than bare land covered by lava.

Forest fires are a necessary part of the forest’s life cycle. The professor gave a few examples to support that fact. One example is that a small fire can help prevent a large fire. A forest is continuously growing, so if left unattended for too long, the forest becomes dense and is vulnerable to a destructive fire. Another example used was about the forest’s canopy. After a small fire, the canopy opens and allows more sun to cover the forest’s floor. Yet another example used was regarding ashes. The ashes caused by the fire have many minerals and helps with plant growth. Finally, the last example used was about pine trees. A pine tree requires fire to spread its pollen. Ultimately, small forest fires are important to a forest’s ecosystem.

The lecture is about ritualization, which is a behavior that can help identify a certain species. Professor says that ritualization behaviors are often more exaggerated in the animal kingdom. For example, the two bird species that demonstrate a ritualization behavior are the pigeons and the peafowl(peacock). The pigeons and the peafowl(peacock) display ritualization behaviors, mostly using their feathers. For pigeons, they like to attract their mates by using a sweet and soft coo sound. They can also attract their mates by fanning their tales, bowing, and swanking. For peafowls(peacocks), part of their ritualistic behavior to court a mate is to unfold their tale feathers during courtship. Ultimately, both the pigeons and peafowls(peacocks) do so because it becomes a natural instinct for them in the animal kingdom.

The lecture discussed how fungi benefit trees by providing more nutrients to them. The professor used two examples to demonstrate how the fungi provide more nutrients. The first example was regarding how the fungi provide extra nutrients to the tree. The fungi will eat insects and break down non-decomposed material to produce more nutrients for the trees. The second example was regarding how the fungi help transfer larger amounts of nutrients. The fungi create a large pathway to the tree by attaching themselves to the tree and this allows for a larger quantity of nutrients to flow into the tree. Therefore, both examples demonstrated how fungi use different methods to increase the tree’s nutrient consumption.

There are two proposals in the lecture about solving the problem of declining frog populations. The first proposal is about preventing farmers from using harmful pesticides because harmful pesticides are being absorbed by the frogs, attacking their bodies nervous system. So, laws would force the farmers to stop using pesticides and that would reduce the harm to frogs. The second proposal is about preventing infection caused by a fungus that thickens the skin. Thickening of a frog’s skin can lead to death of dehydration, so using antifungal treatments that kill the fungus could protect frog populations from infection. In conclusion, both proposals could dramatically keep the frog population alive and growing.