Content of the Unified State Exam
Reading part
Parts:
- Matching headings and texts
- Matching parts of sentences (gapped text)
- Multiple choice questions
Total points: 14
Time: 30 mins
Exam advice
Multiple Choice Questions
- Read the whole text to get the general meaning.
- Look through the questions, then return to the text and underline the sentences relevant to the question.
- Compare the information in the text to the options and choose the closest possible one.
- Remember about "distractors" which are the elements which are the same as in the text, but they aren't true according to the text. They may be contained in the three wrong answers.
Read the article and choose the best option out of the four given
Прочитайте текст и выполните задания 12–18. В каждом задании запишите в поле ответа цифру 1, 2, 3 или 4, соответствующую выбранному Вами варианту ответа.
Lessons From Lizards: How Scaly Superhealers Can Help Humans
What if, after an accident, you could regrow parts of your body? What if you could repair your injuries without going to the hospital? It may sound like science fiction, but it happens to animals in the wild all the time. You probably know that some lizards can regrow their tails. If caught by a predator, many lizards, like the leopard gecko, can detach a portion of their tail. With the predator busy eating the tail, the lizard can escape. The newly tailless lizard can then regrow or regenerate a replacement tail. But lizards can do more than regenerate their tails. Scientists are beginning to learn that some lizards can also regenerate parts of other organs, like the skin, heart, and brain. So why are some animals like lizards and superhealers while other animals, including people, are not?
We have all experienced scrapes, burns, and cuts, so it is no surprise that the skin is our most frequently injured organ. The skin does more than keep all our insides together. It helps us regulate body temperature; it provides protection against harmful rays from the sun; and it can detect heat, cold, pain, and pressure. In all vertebrates (animals with backbones, including fish, reptiles, and mammals), the skin is made of two main layers: the epidermis and the dermis. The epidermis is the outer layer and the part that we normally see. Beneath the epidermis is the dermis, which is responsible for many of the skin's functions. It contains the blood supply to the skin and has nerves, hair follicles, and sweat glands.
Injuries that cut the dermis result in bleeding and, sometimes, scar formation. Scars happen when the dermis is repaired, but the repair is not perfect. For example, in humans, scarred skin does not regrow hair or sweat glands. Scarred skin is also weaker than uninjured skin. The main protein in skin is called collagen. In uninjured skin, collagen looks like it is woven together, making a zigzag pattern. This zigzag pattern allows the skin to stretch. In scarred skin, the zigzag pattern is lost and instead collagen is arranged into parallel layers. These layers of collagen do not stretch, making the scars more likely to tear apart.
In lizards, injuries to the skin are healed without scarring. That is, the skin is completely regenerated. In fact, it is pretty much impossible to locate the wound site once healing is complete. So, what makes lizards different? Interestingly, all major events that take place during scar formation in mammal skin also occur during skin regeneration in other species. The big differences are how soon wound healing begins after injury, how long healing takes, and the number of cells involved. Regenerating skin typically heals quicker than a similar-sized wound that scars. While it only takes a leopard gecko about 5 days to re-form the epidermis, this process can take between 1 and 2 weeks in humans.
One of the key differences between scarring and regenerating skin involves blood vessels. Before scars are formed, the wound site first develops lots of small, thin-walled blood vessels. These blood vessels lack the multilayered structure of normal blood vessels and are sometimes leaky. In contrast, the wound site of regenerating skin develops fewer blood vessels, and the blood vessels that do form are multilayered, just like the blood vessels in uninjured skin. Some scientists believe that this difference in blood vessel formation is one of the main reasons why human skin scars, while lizard skin regenerates.
The one muscle in the body that never gets a break is the heart. Unlike the muscles in the legs and arms that get to relax when we sleep or watch TV, the heart constantly works, day and night. The heart's job is to move blood around the body. Blood transports oxygen and nutrients to and from all cells while also removing carbon dioxide and waste. This exchange of gases and nutrients is essential for keeping the body alive.
The heart is made up of multiple types of cells, but the ones that do most of the work are the cardiomyocytes. Cardiomyocytes are like microscopic motors, and billions of them work together to create the pumping action of the heart, which allows blood to be sent to all the cells and organs in the body. In humans and other mammals, injured cardiomyocytes are not regenerated. For example, heart injury may happen when someone experiences a heart attack. In a heart attack, the blood vessels in the heart are blocked, preventing the heart from getting oxygen. The cardiomyocytes that die are replaced by collagen, creating a permanent scar. Since these scars do not stretch and squeeze like cardiomyocytes, a scarred heart needs to work much harder to pump blood.
But this is not the case for all animals! Like skin, regions of the heart can be regenerated in some superhealing species. Instead of making scar tissue, some species of fish and lizards can regenerate lost cardiomyocytes. So how does this happen? In these species, when the heart is injured, its existing cardiomyocytes divide to create new ones. These newly formed cells replace those that were lost due to injury. This leads to a heart that looks, but more importantly, works, just like the original.
Why are some animals better at replacing lost cardiomyocytes than others? Their cells have the replication machinery on board to successfully divide, and the cell's environment supports this division.
When scientists try to answer particularly difficult questions, they may turn to subjects that seem unexpected. Lizards probably are not the first thing we would think of if we had an injury to the skin, heart, or brain. However, by studying all kinds of organisms, scientists can better understand the ways we are similar to, and the ways we are different from, other organisms. For instance, some animals scar, whereas others regenerate. If we want to improve how humans heal after injury, a great place to look is toward other animals that are great at healing themselves! As scientists continue to study and better understand the biology of regeneration, this research will enable the development of therapies and treatments to improve human health. The lessons learned from lizards may bring us one step closer to becoming superhealers too!
What, according to the author, is NOT the function of skin?
Keeping all the insides together.
Body temperature regulation.
Protection from rays.
Containing the blood supply.
[ ]
What is true about scarred skin?
It lacks collagen.
It is weaker than uninjured skin.
It is not perfectly repaired.
It cannot stretch.
[ ]
Why can't human skin regenerate like a lizard's?
It contains blood vessels.
It contains multilayered blood vessels.
It contains leaky blood vessels.
It contains thin-walled and leaky blood vessels.
[ ]
How is a permanent scar on the heart formed?
Collagen replaces cardiomyocytes to create it.
Blocked blood vessels cause it.
A lack of oxygen creates it.
Dead cardiomyocytes create it.
[ ]
This in "But this is not the case for all animals!" (paragraph 8) refers to...
Scarred heart.
Increased blood pumping
A lack of stretching.
Squeezing.
[ ]
What helps some species regenerate their hearts?
Regeneration of lost recdiomyocytes.
Devision of cerdiomyocytes.
Newly formed cells.
Superhealing abilities.
[ ]
How does the author summarize the article?
It's important to study differences between organisms.
It's important to understand that various species regenerate differently.
It's important to study other species to develop therapies.
It's important to study how lizards regenerate.
[ ]
The maximum score is 7 points for 7 correct answers.
For each correct answer, 1 point is given.
The score for the task:[ ] out of 7.
The correct answer is 4 (The skin does more than keep all our insides together. It helps us regulate body temperature; it provides protection against harmful rays from the sun; and it can detect heat, cold, pain, and pressure.).
The correct answer is 2 (Scarred skin is also weaker than uninjured skin.).
The correct answer is 4 (Before scars are formed, the wound site first develops lots of small, thin-walled blood vessels.).
The correct answer is 1 (The cardiomyocytes that die are replaced by collagen, creating a permanent scar.).
The correct answer is 1 (Since these scars do not stretch and squeeze like cardiomyocytes, a scarred heart needs to work much harder to pump blood.).
The correct answer is 2 (In these species, when the heart is injured, its existing cardiomyocytes divide to create new ones.).
The correct answer is 3 (As scientists continue to study and better understand the biology of regeneration, this research will enable the development of therapies and treatments to improve human health. As scientists continue to study and better understand the biology of regeneration, this research will enable the development of therapies and treatments to improve human health.).