1.
Which phylum contains the vertebrates?
Correct Answer
B. Chordata
Explanation
The phylum Chordata contains the vertebrates. This is because vertebrates are characterized by having a backbone or spinal column, which is a defining feature of the Chordata phylum. Other organisms in this phylum include fish, birds, mammals, and reptiles. Arthropoda, Annelida, Mollusca, and Porifera are all different phyla that do not contain vertebrates.
2.
A notochord is
Correct Answer
B. Cells surrounded by a sheath to form a stiff dorsal supporting rod.
Explanation
The correct answer is "cells surrounded by a sheath to form a stiff dorsal supporting rod." The notochord is a structure found in all vertebrate embryos. It consists of cells that are surrounded by a sheath, forming a stiff rod-like structure that provides support to the developing embryo. As the embryo develops, the notochord will eventually be replaced by the vertebral column or backbone.
3.
Although several groups have been proposed as the chordate ancestors, embryological evidence indicates the chordates have probably descended from the
Correct Answer
C. Echinoderm larvae.
Explanation
The correct answer is echinoderm larvae. Embryological evidence suggests that chordates, including humans, have likely descended from echinoderm larvae. This evidence includes similarities in the early development of both echinoderms and chordates, such as the presence of a hollow nerve cord and a notochord. This suggests a common ancestor between these two groups. Other proposed groups, such as ectoproct larvae, trochophore larvae of Mollusca, primitive forms of Obelia in the phylum Cnidaria, and larval dragonflies in the phylum Arthropoda, do not have the same embryological evidence to support their ancestry to chordates.
4.
The three defining characteristics of chordates are
Correct Answer
E. Gill arches or pHaryngeal pouches/dorsal hollow nerve cord/notochord
Explanation
The correct answer is gill arches or pharyngeal pouches/dorsal hollow nerve cord/notochord. Chordates are characterized by the presence of gill arches or pharyngeal pouches, which are structures involved in respiration and feeding. They also have a dorsal hollow nerve cord, which develops into the central nervous system, and a notochord, which provides support and structure. These three characteristics are unique to chordates and distinguish them from other animal phyla.
5.
Although adult tunicates are stuck to the ocean bottom, they are considered early relatives of vertebrates because
Correct Answer
C. Tunicate larvae have a notochord.
Explanation
Tunicate larvae have a notochord. The notochord is a defining characteristic of vertebrates, as it is a flexible rod that runs along the length of their body and provides support. The presence of a notochord in tunicate larvae suggests a shared evolutionary history with vertebrates, making them early relatives of vertebrates. This is significant because it indicates that tunicates are part of the same lineage that eventually gave rise to vertebrates.
6.
In schooling, fish rely on sensitivity to vibration and water currents. This is provided by cells located inside
Correct Answer
D. The lateral line.
Explanation
Fish rely on sensitivity to vibration and water currents, which is provided by cells located inside the lateral line. The lateral line is a sensory organ found in most fish that runs along the length of their body. It contains a series of sensory cells that can detect changes in water pressure and movement. These cells help fish navigate in their environment, detect prey, and avoid predators. The other options, such as the caudal fin, gills, swim bladder, and scales, do not play a direct role in providing sensitivity to vibration and water currents.
7.
Which of these characteristics is NOT found in the amphibians?
Correct Answer
B. Internal fertilization
Explanation
Amphibians are known for their thin moist skin, small inefficient lungs, aquatic larvae, and eggs with a gelatinous covering. However, internal fertilization is not a characteristic commonly found in amphibians. Internal fertilization refers to the process where fertilization of eggs occurs inside the body of the female. In most amphibians, fertilization occurs externally, where the female lays eggs and the male fertilizes them externally. Therefore, internal fertilization is not found in amphibians.
8.
Which of these characteristics first developed in reptiles?
Correct Answer
A. Amniotic egg
Explanation
The amniotic egg first developed in reptiles. This type of egg has a specialized membrane called the amnion that surrounds the embryo, providing protection and allowing it to develop in a terrestrial environment. This adaptation allowed reptiles to reproduce on land, freeing them from the need to lay their eggs in water like amphibians. The development of the amniotic egg was a significant evolutionary step that contributed to the success of reptiles and their ability to colonize diverse habitats.
9.
When a snake flicks its tongue out, it must return the tips of its
Correct Answer
E. Jacobson's organ
Explanation
When a snake flicks its tongue out, it is using Jacobson's organ. This organ is located in the roof of the snake's mouth and is used for chemoreception. By flicking its tongue out and then retracting it, the snake collects chemical particles from the environment. These particles are then transferred to the Jacobson's organ, where they are analyzed to detect prey, predators, or potential mates. This behavior is essential for a snake's survival as it helps them navigate their surroundings and find food.
10.
Characteristics of birds include all of the following EXCEPT
Correct Answer
E. External fertilization.
Explanation
Birds do not exhibit external fertilization, as they have internal fertilization. This means that the male bird's sperm fertilizes the female bird's eggs inside her body. This is different from external fertilization, where the eggs are fertilized outside of the body, typically in water. Birds have reptile-like scales and claws, a constant warm body temperature, modified reptilian scales called feathers, and hard-shelled eggs, all of which are characteristics unique to birds.
11.
Mammals are different from birds in all these characteristics EXCEPT
Correct Answer
C. Constant body temperature.
Explanation
Mammals and birds both have hair, mammary glands, and give birth to live young. However, mammals do not have a constant body temperature like birds do. Mammals are able to regulate their body temperature internally, whereas birds are able to maintain a constant body temperature regardless of external conditions.