Practice Questions Flashcards
(39 cards)
A person with a low red blood cell count may often feel tired. Explain why?
People with a low red blood cell count have fewer cells to transport oxygen to their tissues. As
a result, they may feel fatigued due to decreased available oxygen. A common condition that
exhibits chronic fatigue is anemia. Anemia is a condition that results from low iron levels which can
decrease the red blood cell count in the body.
Compare the functions of the three types of blood vessels in the circulatory system
Arteries: arteries’ major function is to rapidly transport high-pressured blood from the heart to the capillaries in body tissues
Veins: veins cannot transport high-pressured blood because of their thin walls. Venous valves prevent backflow
Capillaries: capillaries connect arteries and veins. their main function is to exchange materials between blood and body cells.
What is a vestigial organ? Give an example
It is an organ that is reduced in size and no longer has a function. e.g. appendix
What is a homologous structure? Give an example
structures that are similar in related organisms because they were inherited from a common ancestor, but may or may not have the same function. e.g. a bat’s wing, a human arm, and a whale flipper are homologous structures because they were inherited from a common ancestor, but have different functions
What is an analogous structure? Give an example.
structures that are similar in unrelated organisms. they evolved to do the same job, not because they were inherited from a common ancestor.e.g wings of bats and birds.
DDT is an insecticide that was first used in the 1940s to kill mosquitos and stop the spread of malaria. At first, it was
highly effective. However, over years, people noticed that it was becoming less and less effective. A
possible explanation for this was that the insects were becoming resistant to DDT.
Explain how the resistance may have evolved.
The few mosquitos that were resistant to DDT survived and reproduced, whereas those that were not
resistant were killed by the insecticide. The succeeding populations of mosquitoes were more resistant
to DDT therefore increasing the population of resistant mosquitos.
Extremely rapid or deep breathing, which is called hyperventilation, is caused by lower-than-normal levels of carbon dioxide in the blood. Why does breathing into a paper bag stop hyperventilation?
Breathing into a paper bag is a technique that can help regulate hyperventilation by allowing the person to inhale the CO2 they exhale, which helps increase CO2 levels in the blood2. This increase in CO2 levels can help regulate breathing and reduce the symptoms of hyperventilation
Many people think that it is natural for blood pressure to increase significantly with age. Explain why this is just a myth.
This is a myth because it is based on the tendency of older people to have high blood pressure because of years of high-fat diets and other behaviors that increase the chances
of developing high blood pressure. High blood pressure can be unhealthy at any age. Young people can develop high blood pressure, especially if they are overweight, do not
exercise, or have certain illnesses.
Distinguish between systolic pressure and diastolic pressure.
Systolic: blood pressure when the heart beats while pumping blood
Diastolic: blood pressure when the heart relaxes and fills with blood
Suppose your doctor prescribed an antibiotic that killed all the bacteria in your body. What effect would this have on
your digestive system?
An antibiotic that kills all the bacteria in your body would destroy the beneficial bacteria in the large intestine
that normally help remove water from waste. As a result, we would develop vitamin deficiencies since the bacteria that normally produce vitamins are killed. Bacteria that usually control the growth of harmful bacteria would be gone, causing harmful bacteria to reproduce and cause multiple health issues in our intestines.
Suppose a rockslide isolates a very small number of animals from the rest of their population. How might this
reproductive isolation impacts the long-term survival of the new, smaller population?
The limited genetic variation in the isolated individuals might make them less able to adapt to changing conditions, and this would threaten their survival. However, by chance, they could possess genetic traits that made them especially well-suited to the new environment, and this would enhance their survival
Why are maple trees tapped for their sugar in the early spring rather than in the summer or autumn? Use your knowledge of a plant vascular system to support your answer
In early spring, the daily rise and fall of temperature causes the sap to start flowing up from the tree’s roots
and through the phloem in the newly forming leaves. During the summer and autumn, the flow would be in the
opposite direction and the sap would not be as concentrated.
Describe what problems could result if an endangered species were introduced into a nonnative habitat.
This could have several negative consequences. The environment may not have the necessary resources to support the population, leading to a decline, and even an extinction of the species. The species may face competition from other species also endangering their population. Conversely, some species become invasive and reproduce rapidly leading to a decline in biodiversity.
Which kingdom does it belong to? Specimen A: This unicellular organism is found at the bottom of a muddy puddle and moves with a single whip-like tail. This organism has been observed under a microscope feeding on organic material. While looking at the organism under the microscope you observe that it is simple in structure with a cell wall, no enclosed nucleus, and no membrane-bound organelles.
Because this organism is unicellular, has no nucleus, and no membrane-bound organelles, it matches the description of Kingdom Eubacteria.
Which kingdom does it belong to? Specimen B: This organism was found attached to a dead log in a forested area of the island. It has a long stalk with a cloud-shaped structure at the top. When a slice of it is observed under a microscope many cells can be observed with cell walls made of chitin. You can also observe a defined nucleus and organelles. While it has been hard to observe this specimen in the act of feeding you have observed that the dead log where it was found has hyphae attached to this organism and they appear to be breaking down the log.
Because this organism has cell walls made of chitin, has a defined nucleus and organelles, and has hyphae breaking down the log, it belongs to Kingdom Fungi.
Which kingdom does it belong to? Specimen C: This organism was found growing in the forested area and bright pink flower-like structures can be found on it. The main body of the organism appears green and stiff. When a slice of this organism is viewed under the microscope you observe many cells that have cell walls made of cellulose, a defined nucleus, and organelles, such as chloroplasts that appear to give the organism it’s color. While observing this organism you have noticed that when it has access to sunlight, water, and air it tends to grow rapidly. You have also observed many insects visiting the bright pink flower-like structures.
Because this organism has cell walls made of cellulose, a defined nucleus and organelles, and chloroplasts to make its own food, it belongs to Kingdom Plantae.
Which kingdom does it belong to? Specimen D: This organism was found on the surface of a shallow pond. When viewed under a microscope appears to be made of only one cell, it is shaped like the sole of a shoe and is covered with tiny hair-like cilia that help it to move around in the water. It appears to feed on organic matter floating in the water and it has no coloring since it is so small.
Because this organism is unicellular, has cilia to move around, and feeds on organic matter making it a heterotroph, it belongs in Kingdom Protista.
Which kingdom does it belong to? Specimen E: This organism is highly motile and is both multicellular and eukaryotic, but it cannot make its own food (heterotrophic).
Because this organism is multicellular, eukaryotic, and heterotrophic, it belongs to Kingdom Animalia
Many bacteria and protists have the ability to switch between sexual and asexual reproduction. Why would this reproductive strategy be successful for these organisms?
Asexual reproduction is a simpler and faster process that allows for rapid population growth and adaptation to changing environmental conditions. Sexual reproduction allows for greater genetic diversity increasing the chances of survival in a population. By switching between both methods, bacteria, and protists can take advantage of both processes depending on the environmental conditions they face. This allows them to thrive in many environments.
What are the four major threats to biodiversity? Be sure to describe a specific example of each.
1) Habitat Destruction: Increased land use for agriculture that reduces wildlife habitat.
2) Introducing foreign species: The introduction of non-native species to an ecosystem where they don’t have a natural predator can lead to an imbalance in their effect on the environment.
3) Over-exploitation: Overfishing, overhunting, and any process that takes away large amounts of a population at one time can lead to an imbalance of the ecosystem’s food chain and overall health.
4) Pollution: different types of pollution such as air pollution, light pollution, and soil pollution can affect wildlife in many ways. For example, air pollution can cause respiratory issues in mammals.
How does the classification of organisms lead to a better understanding of biodiversity?
It allows biologists to identify organisms and recognize natural groupings. By grouping organisms based on shared characteristics, we can identify patterns of diversity and the relationships between different species. We can also identify new species that occur over time.
Explain what factors could be leading to the loss of a keystone species like the honeybee
A rapid change in the ecosystem could lead to negative impacts on a keystone species. Things like pesticides, pollution, and loss of habitat can impact a keystone species so greatly to the point they cannot function in an ecosystem. Because it is a keystone species, other species will be negatively impacted as well. For example,
Suppose you overhear someone saying that bacteria are disgusting, dirty organisms that serve no purpose. How would you refute this using examples?
Bacteria are useful in many ways to individuals and in society. Some ways that bacteria can be beneficial are in the form of probiotics (helpful bacteria in our intestines to protect from harmful toxins), nitrogen fixation (bacteria can convert N2 to NO3 since N2 can’t be used by organisms, but nitrate can), Gene Therapy (bacteria can be used to target tumors and treat disorders like diabetes), Bioremediation (bacteria is used to remove or neutralize polluted soils and water)
Why would it be important for an animal breeder to know the genotype of an animal and not only its phenotype? Be sure to use examples to help explain.
It would be important for an animal breeder to know the genotype of an animal in order to breed for desired
traits easily or against harmful traits. By knowing the genotype, the breeder will know if the animal is a carrier
for a certain trait. If only the phenotype is known it is harder to tell if the animal is a carrier without breeding
a test-cross. Another example is in the case of breeding for disease resistance. If a breeder wants to produce animals that are resistant to a particular disease, they need to know the genotype of the parent animals to determine the probability of the offspring inheriting the desired trait
