2021 NY Regent Living Environment
By Sara Cowley
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Last updated about 2 months ago
85 Questions
Note from the author:
From the New York State Education Department. The University of the State of New York Regents High School Examination Living Environment v202. Internet. Available from https://www.nysedregents.org/LivingEnvironment/621/lenv-v202-exam.pdf; accessed 3, May, 2023.
From the New York State Education Department. The University of the State of New York Regents High School Examination Living Environment v202. Internet. Available from https://www.nysedregents.org/LivingEnvironment/621/lenv-v202-exam.pdf; accessed 3, May, 2023.
Base your answers to questions 38 and 39 on the information below and on your knowledge of biology
Ulcers: Mystery Solved
Stomach ulcers are painful sores that develop in the stomach. Doctors once thought that ulcers were caused by stress. In the 1980s, a pair of physicians, Barry J. Marshall and J. Robin Warren, questioned the cause of ulcers. They found the bacterium Helicobacter pylori in the ulcer tissue of their patients. Even though they repeatedly presented their findings to colleagues, they were ignored until Marshall performed an astonishing experiment: He drank broth containing the bacteria and made himself sick with an ulcer! He then cured himself by taking an antibiotic.
The results were published in 1985, but it took another 10 years for doctors to regularly use antibiotics to treat ulcers. Marshall and Warren received a Nobel Prize in 2005 for this discovery.
Base your answers to questions 48 and 49 on the information below and on your knowledge of biology.
A scientist added an antibiotic to a Petri dish containing bacterial colonies. A day later, the scientist noticed that many colonies had died, but a few remained. The scientist continued to observe the dish and noted that, eventually, the remaining colonies of bacteria increased in size.
Base your answers to questions 56 through 58 on the passage below and on your knowledge of biology.
Indian Ocean Ecosystem in Danger
The Indian Ocean is under increasing environmental pressures. Until recently, this ocean was considered to have the least ecologically disrupted coastline. However, as the surface water temperatures have increased, there has been a reduction in the phytoplankton population (microscopic producers). This reduction in phytoplankton has been linked to a decline in some fish populations.
Also affecting the fish populations is the urbanization of coastal areas. As the human population grows in this area, more of the coastline region is being developed. In addition, the mining of natural resources has led to oil spills, the destruction of mangrove forests, and an increase in the area’s acidity level.
Countries along the coast are trying to encourage development while, at the same time, trying to maintain a healthy coastal ecosystem.
Base your answers to questions 59 through 61 on the photo and reading passage below, and on your knowledge of biology.
Invasive Water Chestnuts Challenge Environmentalists
Environmental scientists are troubled by the rapid spread of the water chestnut plant. This invasive plant is a freshwater species with leaves that blanket the surface of water. The leaves grow so densely, they stop people from swimming and prevent boats from moving.
Invasive water chestnut leaves prevent 95% of the sunlight from reaching the water below. Local animals and insects cannot eat this plant. New York ecosystems infested by the water chestnut are quickly disrupted. Water chestnut seeds can survive more than ten years under water in the sediments.
The most effective way to kill the water chestnut is to pull out each plant by hand. This can be done in a small pond, but for rivers and lakes that are blocked by huge numbers of water chestnut plants, other methods are needed. Chemical herbicides kill the leaves, but, after several weeks, the water chestnut plants grow back. Large machines have been used to clear these plants and seeds from the water and sediments of ecosystems, but the machines remove many other organisms too.
Base your answers to questions 62 and 63 on the information below and on your knowledge of biology.
Rising CO2 [Carbon Dioxide] Levels in Ocean Block Sharks’ Ability to Smell Prey
…Changes in the chemistry of the world’s oceans expected by century’s end could impact the hunting ability of sharks, which depend heavily on their sense of smell to locate prey, researchers say.
As ocean waters turn increasingly acidic from absorbing atmospheric CO2 created by human activities, the odor-detecting ability of sharks to locate prey could diminish, they say…
Source: Jim Algar, Tech Times, 9/9/14
Base your answers to questions 64 through 66 on the information and photo below and on your knowledge of biology. The photo shows an adult female weasel.
Weasels Are Built for the Hunt
Weasels are fierce and quick-witted carnivores that must compete for food with larger predators. Their slender, elongated body plan allows them to pursue prey in tight spaces that other carnivores can’t enter, a key factor in controlling rodent and rabbit populations. This body plan is important to the success of weasels. Female weasels have evolved to give birth to fetuses that have not fully completed development. The fetuses complete their development externally. In this way, there is no baby bump to limit the mother’s access to tight feeding locations.
A high energy level is key to the weasel’s success in capturing prey, but it comes at a price. To survive, weasels need to eat a third of their body weight per day. This need can make them unpopular with poultry farmers, because they can enter through the smallest opening and consume large numbers of chickens.
Base your answers to questions 67 and 68 on the information and diagram below and on your knowledge of biology.
HIV Infection
The human immunodeficiency virus (HIV), which can lead to AIDS, is a type of virus that adds its genetic material to the DNA of the host cell. HIV reproduces within the host cell and exits through a process called budding.
In the process of budding, the newly forming virus merges with the host cell membrane and pinches off, taking with it a section of the host-cell membrane. It then enters into circulation.
Base your answers to questions 69 through 72 on the information below and on your knowledge of biology.
Snakes Used to Have Legs and Arms Until These Mutations Happened
The ancestors of today’s slithery snakes once sported full-fl edged arms and legs, but genetic mutations caused the reptiles to lose all four of their limbs about 150 million years ago, according to two new studies. …
Both studies showed that mutations in a stretch of snake DNA called ZRS (the Zone of Polarizing Activity Regulatory Sequence) were responsible for the limb-altering change. But the two research teams used different techniques to arrive at their findings. …
…According to one study, published online today (Oct. 20, 2016) in the journal Cell, the snake’s ZRS anomalies [differences] became apparent to researchers after they took several mouse embryos, removed the mice’s ZRS DNA, and replaced it with the ZRS section from snakes. …
…The swap had severe consequences for the mice. Instead of developing regular limbs, the mice barely grew any limbs at all, indicating that ZRS is crucial for the development of limbs, the researchers said.
Looking deeper at the snakes’ DNA, the researchers found that a deletion of 17 base pairs within the snakes’ DNA appeared to be the reason for the loss of limbs.
Source: http://www.livescience.com/56573-mutation-caused-snakes-to-lose-legs.htm
Base your answers to questions 73 and 74 on the information and chart below and on your knowledge of biology.
Finding Relationships Between Organisms
Organisms living in the same environment may have similar body structures, but this does not always indicate a close biological relationship. The chart below provides information about four organisms that live in an Antarctic Ocean ecosystem.
Base your answers to questions 76 and 77 on the passage below and on your knowledge of biology.
A recent study of Darwin’s finches in the Galapagos Islands identified the gene, HMGA2, that is involved in beak size. It played a role in which finches feeding on smaller seeds survived a severe drought in 2004-2005. Following the drought, the average size of the medium ground finch beak decreased. This change was traced directly to changes in the frequency of the HMGA2 gene. Previous studies have shown that HMGA2 affects body size in animals, including dogs and horses, and even humans.
Base your answers to questions 79 and 80 on the diagram below and on your knowledge of biology. The diagram represents a hypothetical result of a technique used in a lab.
Base your answers to questions 84 and 85 on the information below and on your knowledge of biology.
A Clothespin Experiment
A student in a Living Environment class designed an experiment to investigate if the number of times a student squeezes a clothespin varies with the hand used. Her hypothesis was that students could squeeze a clothespin more times in a minute when they used their dominant hand than when they used their nondominant hand.
During her investigation, she first squeezed and released a clothespin as often as possible for 20 seconds with her dominant hand. She recorded the number of squeezes in a chart.
She performed three trials before resting. After that, she repeated the entire procedure with her nondominant hand. Some of the data are shown in the table below.
