Practice Questions

Question 1

A person with a low red blood cell count may often feel tired. Explain why?

Answer 1

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.

Question 2

Compare the functions of the three types of blood vessels in the circulatory system

Answer 2

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.

Question 3

What is a vestigial organ? Give an example

Answer 3

It is an organ that is reduced in size and no longer has a function. e.g. appendix

Question 4

What is a homologous structure? Give an example

Answer 4

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

Question 5

What is an analogous structure? Give an example.

Answer 5

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.

Question 6

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.

Answer 6

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.

Question 7

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?

Answer 7

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

Question 8

Many people think that it is natural for blood pressure to increase significantly with age. Explain why this is just a myth.

Answer 8

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.

Question 9

Distinguish between systolic pressure and diastolic pressure.

Answer 9

Systolic: blood pressure when the heart beats while pumping blood
Diastolic: blood pressure when the heart relaxes and fills with blood

Question 10

Suppose your doctor prescribed an antibiotic that killed all the bacteria in your body. What effect would this have on
your digestive system?

Answer 10

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.

Question 11

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?

Answer 11

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

Question 12

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

Answer 12

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.

Question 13

Describe what problems could result if an endangered species were introduced into a nonnative habitat.

Answer 13

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.

Question 14

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.

Answer 14

Because this organism is unicellular, has no nucleus, and no membrane-bound organelles, it matches the description of Kingdom Eubacteria.

Question 15

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.

Answer 15

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.

Question 16

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.

Answer 16

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.

Question 17

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.

Answer 17

Because this organism is unicellular, has cilia to move around, and feeds on organic matter making it a heterotroph, it belongs in Kingdom Protista.

Question 18

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).

Answer 18

Because this organism is multicellular, eukaryotic, and heterotrophic, it belongs to Kingdom Animalia

Question 19

Many bacteria and protists have the ability to switch between sexual and asexual reproduction. Why would this reproductive strategy be successful for these organisms?

Answer 19

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.

Question 20

What are the four major threats to biodiversity? Be sure to describe a specific example of each.

Answer 20

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.

Question 21

How does the classification of organisms lead to a better understanding of biodiversity?

Answer 21

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.

Question 22

Explain what factors could be leading to the loss of a keystone species like the honeybee

Answer 22

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,

Question 23

Suppose you overhear someone saying that bacteria are disgusting, dirty organisms that serve no purpose. How would you refute this using examples?

Answer 23

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)

Question 24

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.

Answer 24

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

Question 25

Why is it so important to protect yourself from exposure to chemicals or radiation that could damage your DNA? How could such damage affect future generations?

Answer 25

Exposure to hazards such as radiation and toxic chemicals can damage your DNA. This damaged DNA can lead to mutations and cause problems in the cell cycle resulting in abnormal replication of cancer cells.
Damaged DNA can be passed on to offspring and negatively affect their genetic viability. Mutations
can give rise to new traits whether negative or positive. Cancer cells can grow and inhibit normal cell
function which can lead to many health problems.

Question 26

What are three concerns that individuals have about the implications of genomic and related biotechnologies?

Answer 26

Ethical concerns:
- Is this method of change appropriate?
- How does this impact an individual’s religious beliefs?
- Are we creating new, dangerous organisms such as viruses?
- Will designer humans be the next step?
Environmental concerns:
- How will these changes affect our environment long term?
- How will these changes affect consumers of these products?
Political/Societal concerns:
- How will these technologies be used and regulated in society?

Question 27

Compare and contrast the transportation of water and sugar up and down a plant

Answer 27

Water and sugars are transported up and down a plant through the vascular tissues: xylem and phloem. The xylem transports water and the phloem transports food and nutrients. The xylem is unidirectional; its job is to make sure water flows upward. However, the phloem is bidirectional and transports food and nutrients to all of the plants.

Question 28

Describe how hormones and tropisms are related.

Answer 28

When a plant receives an external stimulus, it responds by changing its growth. A plant’s response to an external stimulus is called a tropism, and tropisms generally lead to hormone production. The hormones created regulate how a plant grows in response to tropisms. The four main tropisms are geotropism (response to gravity), hydrotropism (response to water), phototropism (response to light), and thigmotropism (response to touch). For example, when certain plants are exposed to light, (phototropism) a hormone called auxin shifts to the side of the plant opposite the light. The hormone auxin causes the cells on the side of the plant opposite the light to grow and elongate, thereby altering plant growth and bending the plant leaves toward the light.

Question 29

New volcanic islands are sometimes formed in the ocean. They are often populated quickly by plants, even if they are far from the nearest land. The first species to arrive usually have berries. Why? Why do other plants take longer to colonize?

Answer 29

The first species will likely have berries because berries are an attractive type of fruit for birds, which are a form of seed dispersal. Birds are typically among the first to colonize a new island, as they help to disperse the seeds of berry-producing plants to other parts of the island. Other plants may take longer because they use other methods of dispersal including water and wind.

Question 30

Plants are vital parts of our daily life. Identify 4 different ways that plants are used but don’t include food.

Answer 30

Plants are used in every industry of life. From food to the environment, to recreational uses, and pharmaceuticals. Plants play a huge role in the environment. Plants release oxygen into the air through the process of photosynthesis, which is essential for human and animal survival. Plants are an important source of many drugs used in the pharmaceutical industry. 25% of all drug prescriptions use plant products. Plants also play a huge role in fuel. Almost half of the world’s annual tree harvest is used as fuel for heating and cooking. Finally, Plants play a major role in building, industry, and homes. Plants can be used in oils, lubricants, paints, and ropes.

Question 31

Compare the structural similarities between a bat’s wing, a human’s arm, and a whale’s flipper. How is the limb in each of the cases above structurally modified to perform its function?

Answer 31

The bat’s wing, human’s arm, and whale’s flipper are all homologous structures. They’re similar in that they have a large upper bone, 2 lower bones, and many smaller bones in the wrist area. Despite their different functions, the structural similarities between the 3 limbs provide evidence of their shared evolutionary history. The bat’s wing is adapted for flight, the human’s arm is adapted for dexterity and a wide range of motion, and the flipper of a whale is adapted for swimming.

Question 32

Explain why speciation would more likely occur on islands further from a mainland, such as the Galapagos islands, than on an island close to the mainland, such as PEI.

Answer 32

Speciation happens when a species’ populations are separated and they begin to develop differing characteristics over time through natural selection so much that they can not successfully reproduce with the other population. Because an increase in distance from an island
to the mainland can restrict travel back and forth and mixing of the populations there is a greater chance that the two populations will diverge to the point of becoming separate species.

Question 33

Some people believe that because a new influenza vaccine is needed each year, there is no point in getting vaccinated.
Discuss some of the advantages of getting vaccinated each year. Discuss some of the advantages of getting vaccinated each year

Answer 33

Getting vaccinated each year has several advantages. Firstly, the virus can mutate rapidly, which means the virus circulating this year may have mutated in the next year. By getting vaccinated, you make sure you have protection against the latest version. Secondly, getting vaccinated helps protect not just you but the people around you who may be more susceptible to the virus such as the elderly, infants, and people with weakened immune systems. There are of course disadvantages. One major disadvantage is people may experience side effects from the vaccine such as a fever. Another disadvantage is the vaccine may not have total protection against the influenza virus since it rapidly mutates.

Question 34

Does evolution make organisms ‘better’? Justify your answer.

Answer 34

Evolution is a process of change over time, driven by natural selection, genetic drift, and other mechanisms. While these processes can lead to important adaptations that increase an organism’s chances of reproduction and survival, it doesn’t make the organism ‘better’. For example, a species that is well adapted to an environment may become less adapted if the environment changes. A certain trait may be desirable in an environment but will lead to extinction if the environment changes. Overall, evolution can improve an organism’s chance of survival but it doesn’t make the organism ‘better’ in an absolute sense.

Question 35

Using an example, explain what Darwin meant by descent with modification.

Answer 35

Darwin meant that all organisms were related through descent from some unknown ancestor. He proposed that as the descendants of that ancestral organism spread into various habitats over millions of years, they accumulated diverse modifications. One example of descent with modification is the evolution of finches on the Galapagos Islands which Darwin observed on his voyage. The finches had different beak shapes which he hypothesized were adaptations for different food sources. The finches descended from a common ancestor, and over time their beaks modified according to the different environments they were in.

Question 36

Explain how the study of evolution helps us understand Pesticide resistance in crops

Answer 36

With evolution, we know that if we use crops genetically modified to resist pests, those pests who survive to feed on the crop and reproduce will then over time pass on traits that help the population to resist the pesticides and be able to feed on the crop.

Question 37

On his voyage with the Beagle, Charles Darwin carefully studied several species of finches. He found that many had come from a single species, but they had adapted to their environment by choosing different food sources and developing different beak designs to match their choice of food. What pattern of evolution did the finches show?

Answer 37

This is an example of divergent evolution. As time passed, the different species adapted to their lifestyles and became more and more different from other closely related organisms

Question 38

Many species of owls hunt only at night. These winged predators have evolved extremely sensitive hearing to help track insects and other prey. Another night-hunting winged predator, the bat also has an extremely sensitive hearing to track prey in the dark. What pattern of evolution does this show?

Answer 38

This is an example of convergent evolution when organisms are placed in the same environment and are subjected to the same selective pressures causing them to develop similar traits. Owls and bats are not related but both hunt at night using sensitive hearing and flight.

Question 39

Certain plants have evolved hard shells to protect their seeds. At the same time, seed-eating animals evolved powerful jaws and teeth to break through the plant’s tough shells. What pattern of evolution does this show?

Answer 39

This is an example of co-evolution or parallel evolution. The plant developed hard shells because of seed-eating animals and vice-versa. Their evolutionary success is linked to each other