1.
Why are viruses like parasites?
Correct Answer
A. They harm the cells they enter.
Explanation
Viruses are considered like parasites because they harm the cells they enter. Similar to parasites, viruses rely on a host organism to survive and reproduce. Once inside a host cell, viruses hijack the cell's machinery to replicate themselves, often causing damage to the host cell in the process. This harm can lead to various diseases and illnesses in the infected organism.
2.
The genetic material of a virus is found it its
Correct Answer
B. Core
Explanation
The genetic material of a virus is found in its core. The core of a virus contains the genetic material, which can be either DNA or RNA. This genetic material carries the instructions for the virus to replicate and infect host cells. The coat of the virus, also known as the capsid, is a protective protein shell that surrounds the core. While the coat provides protection and helps the virus attach to host cells, it does not contain the genetic material itself. Therefore, the correct answer is core.
3.
Which of the following statements does NOT describe an active virus?
Correct Answer
C. It "hides" in the host cell.
Explanation
The statement "It 'hides' in the host cell" does not describe an active virus. Active viruses attach to the host cell, take over its function, and help the virus attach to its host. However, hiding in the host cell implies a dormant or latent state where the virus is not actively replicating or causing harm.
4.
What characteristic of viruses makes them useful in gene therapy?
Correct Answer
A. Their ability to enter cells
Explanation
Viruses are useful in gene therapy because of their ability to enter cells. In gene therapy, viruses are modified to carry therapeutic genes into the target cells. Once inside the cell, the viral vector releases the therapeutic genes, which can then be expressed and potentially correct genetic disorders or deliver therapeutic proteins. The ability of viruses to enter cells efficiently makes them effective vehicles for delivering genetic material into the cells of the patient, making them a valuable tool in gene therapy.
5.
Which shape describes some bacterial cells?
Correct Answer
C. Spiral
Explanation
Spiral is the correct answer because some bacterial cells have a spiral shape. This shape is commonly found in bacteria such as spirochetes, which have a long, helical shape resembling a corkscrew. This shape allows them to move efficiently through various environments, such as soil or the human body.
6.
What process results in genetically different bacteria?
Correct Answer
C. Conjugation
Explanation
Conjugation is a process in which bacteria transfer genetic material to one another through direct contact. This process results in genetically different bacteria because during conjugation, the donor bacterium transfers a plasmid (a small, circular piece of DNA) to the recipient bacterium. This plasmid can contain genes that are not present in the recipient bacterium, leading to genetic variation and the potential for new traits or characteristics in the bacteria. Therefore, conjugation is the process that results in genetically different bacteria.
7.
Which of the following is an example of indirect contact that spreads some infectious diseases?
Correct Answer
D. Inhaling infected drops of moisture
Explanation
Inhaling infected drops of moisture is an example of indirect contact that spreads some infectious diseases. When an infected person coughs or sneezes, tiny droplets containing the infectious agent are released into the air. If another person inhales these infected droplets, they can become infected with the disease. This mode of transmission is common for respiratory infections such as the flu or COVID-19. It highlights the importance of wearing masks and practicing good respiratory hygiene to prevent the spread of these diseases.
8.
The best treatment for most viral infections is
Correct Answer
D. Bed rest
Explanation
Bed rest is the best treatment for most viral infections because viral infections are caused by viruses, which cannot be treated with antibiotics. Antibiotics are only effective against bacterial infections. Over-the-counter medicines may help relieve symptoms, but they do not directly treat the viral infection. Vaccines are preventive measures and are not a treatment for an existing viral infection. Bed rest allows the body to conserve energy and focus on fighting off the virus, promoting a faster recovery.
9.
What directly provides energy for a virus?
Correct Answer
B. Its host
Explanation
A virus directly obtains energy from its host. Viruses are obligate intracellular parasites, meaning they cannot produce energy on their own and rely on the host's cellular machinery to replicate and survive. They hijack the host's metabolic processes and resources to generate energy for their own replication and protein synthesis. Therefore, the host serves as the primary source of energy for the virus.
10.
Which of the following structures are always found in bacterial cells?
Correct Answer
B. Ribosomes
Explanation
Ribosomes are always found in bacterial cells. Ribosomes are the cellular structures responsible for protein synthesis. They are present in both prokaryotic and eukaryotic cells. Bacterial cells lack a true nucleus, as their DNA is not enclosed within a membrane-bound organelle. Flagella and coats are not always found in bacterial cells, as they can vary in their presence and structure depending on the specific bacterial species. However, ribosomes are a universal component of all bacterial cells and are essential for their survival and functioning.
11.
Many bacterial diseases can be cured using
Correct Answer
D. Antibiotics
Explanation
Antibiotics are the correct answer because they are medications that can kill or inhibit the growth of bacteria, thereby treating bacterial infections. Toxins are substances produced by bacteria that can cause harm, not cure diseases. Endospores are dormant structures formed by certain bacteria to survive harsh conditions, not a treatment for diseases. Viruses are not effective against bacterial infections as they specifically target and infect host cells, not bacteria. Therefore, antibiotics are the most suitable option for curing bacterial diseases.
12.
The spores that funguslike protists produce
Correct Answer
A. Grown into new organisms
Explanation
The correct answer is "grown into new organisms". Funguslike protists produce spores, which are reproductive structures. These spores have the ability to develop into new organisms under favorable conditions. This process allows the protists to reproduce and increase their population.
13.
What might cause red tides?
Correct Answer
A. Increase in nutrients in the water
Explanation
Red tides are caused by an increase in nutrients in the water. These nutrients, such as nitrogen and phosphorus, can come from sources like agricultural runoff or sewage discharge. The excess nutrients cause an overgrowth of algae, specifically harmful algal blooms, which can release toxins into the water. This leads to the discoloration of the water, giving it a red or brownish hue. The toxins produced by the algae can be harmful to marine life, causing fish kills and other negative ecological impacts.
14.
When are red tides dangerous to humans?
Correct Answer
D. When algae toxins acculmulate in shellfish
Explanation
Red tides are dangerous to humans when algae toxins accumulate in shellfish. Red tides are caused by the rapid growth and accumulation of algae in the water, and some species of algae produce toxins that can be harmful to humans. These toxins can accumulate in shellfish, such as mussels and clams, when they feed on the algae. If humans consume these contaminated shellfish, they can experience symptoms such as nausea, vomiting, and even neurological effects. Therefore, it is important to be cautious and avoid consuming shellfish during red tide events to prevent any potential health risks.
15.
Which statement does NOT describe eutrophication in a pond or lake?
Correct Answer
C. An increase in the amount of oxygen
Explanation
Eutrophication is a process of gradual change in a pond or lake characterized by a build-up of nutrients, leading to an increase in the amount of surface algae. However, it does not result in an increase in the amount of oxygen. In fact, eutrophication often leads to a decrease in oxygen levels due to the decomposition of excess algae, which consumes oxygen in the water. This can result in the death of aquatic organisms that rely on oxygen for survival.
16.
What factor will NOT increase the rate of eutrophication in freshwater?
Correct Answer
D. Eliminating sources of excess nutrients
Explanation
Eliminating sources of excess nutrients will not increase the rate of eutrophication in freshwater. Eutrophication is the process where excessive nutrients, such as nitrogen and phosphorus, enter a body of water and stimulate the growth of algae and other aquatic plants. Farm fertilizer runoff, leaks from sewage treatment plants, and lawn fertilizer runoff all contribute to the excess nutrient load in freshwater, thus increasing the rate of eutrophication. However, by eliminating these sources of excess nutrients, the input of nutrients into the water is reduced, which in turn decreases the rate of eutrophication.
17.
The threadlike structures that make up the bodies of multicellular fungi are called
Correct Answer
A. HypHae
Explanation
Hyphae are the threadlike structures that make up the bodies of multicellular fungi. They are long, branching filaments that form a network called mycelium. Hyphae are responsible for absorbing nutrients from the environment and distributing them throughout the fungus. They play a crucial role in the growth and reproduction of fungi. Nuclei, mold, and cell walls are not the correct answers as they do not specifically refer to the threadlike structures of fungi.
18.
The chemicals that ooze from a fungus' hyphae into its food source.
Correct Answer
B. Break down the food
Explanation
The chemicals that ooze from a fungus' hyphae into its food source are responsible for breaking down the food. Fungi secrete enzymes that help in the decomposition of organic matter, allowing them to obtain nutrients from their surroundings. These enzymes break down complex molecules into simpler ones that can be easily absorbed by the fungus. Therefore, the chemicals released by the fungus serve the purpose of breaking down the food into smaller, more digestible components.
19.
A puffball fungus is a type of
Correct Answer
C. Club fungus
Explanation
A puffball fungus is classified as a club fungus. Club fungi are characterized by their club-shaped reproductive structures called basidia, which produce spores. Puffball fungi have a round or pear-shaped fruiting body that contains powdery spores inside. They belong to the phylum Basidiomycota, which includes mushrooms, toadstools, and other fungi with similar reproductive structures.
20.
A fungus-plant root association is an example of
Correct Answer
B. Symbiotic relationship
Explanation
A fungus-plant root association is an example of a symbiotic relationship because both the fungus and the plant benefit from their interaction. The fungus forms a network of hyphae around the plant roots, increasing the surface area for nutrient absorption. In return, the plant provides the fungus with carbohydrates produced through photosynthesis. This mutually beneficial relationship is known as mutualism, which is a type of symbiosis where both organisms involved benefit from each other's presence.
21.
What do yeast cells use a food source in breadmaking and winemaking?
Correct Answer
A. Sugar
Explanation
Yeast cells use sugar as a food source in breadmaking and winemaking. During fermentation, yeast breaks down the sugar present in the dough or grape juice into carbon dioxide and alcohol. This process helps in leavening the bread dough, making it rise, and in producing alcohol in winemaking. Salt is not used as a food source by yeast cells, and carbon dioxide and alcohol are byproducts of the fermentation process rather than the food source itself.
22.
Like animals, animal-like protists are
Correct Answer
B. HeterotropHs
Explanation
Animal-like protists are heterotrophs because they obtain their energy by consuming other organisms or organic matter. They are unable to produce their own food through photosynthesis like autotrophs. Heterotrophs rely on external sources for their nutrition, and animal-like protists typically feed on bacteria, algae, or other small organisms. They are also unicellular, meaning they are composed of a single cell, and they are not prokaryotes, as they have a nucleus and other membrane-bound organelles.
23.
Where would fungi NOT likely thrive?
Correct Answer
D. Desert
Explanation
Fungi require moisture to thrive, as they obtain their nutrients from organic matter in their environment. The desert, being an extremely dry environment, lacks the necessary moisture for fungi to grow and reproduce. Therefore, fungi are unlikely to thrive in the desert.
24.
What characteristic do all algae share?
Correct Answer
A. They are autotropHs.
Explanation
All algae share the characteristic of being autotrophs, which means they are capable of producing their own food through photosynthesis. This sets them apart from heterotrophs, which rely on consuming other organisms for nutrition. Autotrophy is a defining feature of algae and is essential for their survival and growth. This characteristic allows algae to convert sunlight into energy and produce organic compounds, making them an important part of the food chain and ecosystem.
25.
What characteristics do fungi share?
Correct Answer
B. They are eukaryotes.
Explanation
Fungi share the characteristic of being eukaryotes. This means that their cells have a nucleus and other membrane-bound organelles. Unlike prokaryotes, such as bacteria, fungi have a more complex cellular structure. Fungi are also not autotrophs, as they obtain nutrients by absorbing them from their environment. While some fungi are multicellular, others can exist as single-celled organisms. Therefore, the only characteristic that all fungi share is being eukaryotic.
26.
What bacteria-killing fungus did Fleiming isolate in his 1928 experiment?
Correct Answer
D. Penicillum
Explanation
In his 1928 experiment, Fleming isolated the bacteria-killing fungus known as Penicillum. This fungus is famous for producing the antibiotic substance called penicillin, which has since been used to treat various bacterial infections. Fleming's discovery of penicillin revolutionized medicine and paved the way for the development of many other antibiotics.