In which vertebrates is fertilization exclusively internal? A) Reptiles and amphibians. B) Chondricthyans, osteichthyans and mammals. C) Amphibians, mammals and reptiles. D) Chondricthyans osteicthyans and reptiles, E) Reptiles and mammals. 13. Which of the following is characteristic of all viruses? A) A protein capsid. B) A nucleic acid genome. C) A viral envelope D) A and B only E) A, B and C 14. Apical meristems A) occur only in shoots of plants B) occur only in roots of plants C) occur in both roots and shoots of plants D) allow plants to move from one place to another 15) What is the goal of bioremediation? A) to improve human health with the help of living organisms such as bacteria B) to clean up areas polluted with toxic compounds by using bacteria C) to improve soil quality for plant growth by using bacteria D) to improve bacteria for production of useful chemicals 16) The host range of a virus is determined by _ A) the enzymes carried by the virus B) whether its nucleic acid is DNA or RNA C) the proteins in the host’s cytoplasm D) the proteins on its surface and that of the host 17) Which of the following structures is found in angiosperms, but not in gymnosperms? A) Fruits B) Spores C) Seeds D) Seed coat E) Pollen tube 18.) In examining an unknown animal species during its embryonic development, how can you be sure what you are looking at is a protostome and not a deuterostome? A) There is evidence of cephalization. B) The animal is triploblastic. C) The animal is clearly bilaterally symmetrical. D) You see a mouth, but not an anus.
The Correct Answer and Explanation is:
2. In which vertebrates is fertilization exclusively internal?
Answer: E) Reptiles and mammals.
Explanation:
In reptiles and mammals, fertilization occurs exclusively internally. Both of these groups have evolved mechanisms that ensure that sperm fertilizes the egg within the female’s reproductive tract. This is in contrast to many amphibians and most fish (osteichthyans and chondrichthyans), where fertilization can occur externally in the environment, typically in water. Internal fertilization offers the advantage of protecting the developing embryo from environmental threats and increasing the chances of successful reproduction. Reptiles and mammals also have more complex reproductive strategies, including live birth in mammals (viviparity), though some reptiles still lay eggs (oviparity).
13. Which of the following is characteristic of all viruses?
Answer: D) A and B only.
Explanation:
All viruses share two basic features: a protein capsid and a nucleic acid genome (either DNA or RNA). The protein capsid protects the viral genome and helps the virus attach to host cells. The genome contains the instructions for making new viruses. Not all viruses have a viral envelope, which is a lipid membrane that surrounds some viruses. Viruses that lack this envelope are called non-enveloped viruses, while those that have it, such as HIV, are enveloped viruses.
14. Apical meristems:
Answer: C) Occur in both roots and shoots of plants.
Explanation:
Apical meristems are regions of actively dividing cells located at the tips of roots and shoots in plants. These meristems enable plants to grow in length, which is known as primary growth. Apical meristems are crucial for the growth of both the root system, allowing it to penetrate deeper into the soil, and the shoot system, helping plants to reach upward for light. They are present in both monocots and dicots and are responsible for the growth of new leaves, flowers, and roots.
15. What is the goal of bioremediation?
Answer: B) To clean up areas polluted with toxic compounds by using bacteria.
Explanation:
Bioremediation is a process that uses living organisms, particularly bacteria, fungi, or plants, to remove or neutralize pollutants from contaminated environments. These organisms break down harmful substances, such as oil spills, heavy metals, or pesticides, into less harmful or non-toxic compounds. This is a natural and eco-friendly way of cleaning up pollution, as it avoids the use of harmful chemicals or costly methods.
16. The host range of a virus is determined by:
Answer: D) The proteins on its surface and that of the host.
Explanation:
The host range of a virus refers to the spectrum of host cells that the virus can infect. This is determined by the specific interaction between the viral surface proteins (spikes, glycoproteins) and receptors on the surface of the host cells. The compatibility of these proteins is key for viral entry into the host. Viruses are typically highly specific in the hosts they can infect, and the range of potential hosts is constrained by these molecular interactions.
17. Which of the following structures is found in angiosperms, but not in gymnosperms?
Answer: A) Fruits.
Explanation:
Fruits are a characteristic feature of angiosperms (flowering plants) and are formed from the ovary of the flower after fertilization. Fruits protect and aid in the dispersal of seeds. Gymnosperms (such as conifers) do not produce fruits. Instead, they produce naked seeds, which are not enclosed by an ovary. Angiosperms, therefore, are the only group of plants that produce fruits, making this a distinctive characteristic.
18. In examining an unknown animal species during its embryonic development, how can you be sure what you are looking at is a protostome and not a deuterostome?
Answer: D) You see a mouth, but not an anus.
Explanation:
The key feature that distinguishes protostomes from deuterostomes during embryonic development is the development of the blastopore, the opening that forms during the early stages of development. In protostomes, the blastopore becomes the mouth, while in deuterostomes, it becomes the anus. If you observe an embryo and notice that the first opening becomes the mouth (and not the anus), you are looking at a protostome. Protostomes include animals like arthropods and mollusks, whereas deuterostomes include echinoderms and chordates. This developmental distinction is a fundamental characteristic of the two groups.
