1.
Which of these options is incorrect about the Platyhelminthe phylum?
Correct Answer
E. They are segmented
Explanation
Platyhelminthes are not segmented. They are acoelomates, meaning they lack a body cavity. This is in contrast to segmented worms, such as annelids.
2.
Platyhelminthes demonstarte an increase in complexity over Cnidaria
Correct Answer
A. True
Explanation
Platyhelminthes, also known as flatworms, demonstrate an increase in complexity over Cnidaria, which includes jellyfish and sea anemones. This is because Platyhelminthes have a more advanced body structure and organ systems compared to Cnidaria. Flatworms have bilateral symmetry, a centralized nervous system, and specialized organs for digestion and excretion. In contrast, Cnidaria have radial symmetry, a decentralized nerve net, and a simpler digestive system. Therefore, it can be concluded that Platyhelminthes are more complex in terms of their anatomical organization and physiological functions than Cnidaria.
3.
Platyhelminthes often alternate between ______ and ______ reproduction, this is referred to as ______ of _____
Correct Answer
sexual asexual alternation generations
asexual sexual alternation generations
asexual, sexual, generations
sexual, asexual, generations
Explanation
Platyhelminthes often alternate between sexual and asexual reproduction, this is referred to as alternation of generations. This means that they have a reproductive cycle where they reproduce both sexually and asexually in different generations. In some generations, they reproduce sexually, while in others they reproduce asexually. This allows them to have genetic diversity through sexual reproduction and rapid population growth through asexual reproduction.
4.
Platyhelminthe phylum includes the classes____
Correct Answer(s)
A. Turbellaria
C. Cestoda
F. Trematoda
G. Monogenea
Explanation
The correct answer includes the classes Turbellaria, Cestoda, Trematoda, and Monogenea. These classes belong to the phylum Platyhelminthe, which is commonly known as flatworms. Turbellaria are free-living flatworms, Cestoda are tapeworms, Trematoda are flukes, and Monogenea are ectoparasitic flatworms. These classes share similar characteristics such as having a flat body shape and lacking a true body cavity.
5.
Platyhelminthes are an example of_______
Correct Answer
B. Serial repetition
Explanation
Platyhelminthes, also known as flatworms, exhibit serial repetition in their body structure. This means that their body is composed of repeated segments or units along the length. Each segment contains the same set of organs and systems, allowing for efficient movement and coordination. This characteristic of serial repetition is seen in various flatworm species, enabling them to adapt to different environments and perform specific functions within each segment. Therefore, the correct answer is serial repetition.
6.
Platyhelmithes have a ____ and ____ skin.
Correct Answer
ciliated permeable
Explanation
Platyhelminthes have a ciliated permeable skin. This means that their skin is covered in tiny hair-like structures called cilia, which help with movement and feeding. Additionally, their skin is permeable, allowing for the exchange of gases and nutrients with the environment. This adaptation is important for flatworms, as it enables them to efficiently obtain oxygen and nutrients through their skin, despite lacking a specialized respiratory or circulatory system.
7.
The consequences of having such skin properties include:
Correct Answer(s)
B. Vulnerability to water in-flow
C. Modification to resist attack
D. In danger of water loss
F. Asisting attachment
Explanation
The given answer lists several consequences of having certain skin properties. Vulnerability to water in-flow means that the skin is prone to allowing water to enter. Modification to resist attack suggests that the skin has undergone changes to protect against harm. In danger of water loss implies that there is a risk of losing water. Assisting attachment indicates that the skin helps in attaching or sticking to surfaces.
8.
Some platyhelminthes have primitive eyes called____ ____ ______
Correct Answer(s)
pigment cup ocelli
Explanation
Platyhelminthes, also known as flatworms, have primitive eyes called pigment cup ocelli. These eyes are simple in structure and consist of a pigment cup that contains light-sensitive cells. The pigment cup helps to focus light onto the light-sensitive cells, allowing the flatworm to detect changes in light intensity. While these eyes are not as complex as those found in higher organisms, they still allow the flatworm to perceive light and shadows in their environment.
9.
Platyhelmithes larvae are:
Correct Answer
C. Mullers larvae
Explanation
Mullers larvae are the larvae of the phylum Platyhelmithes. They are named after the German zoologist Johannes Peter Müller. Mullers larvae are free-living and have a ciliated body. They are typically oval or elongated in shape and have a distinct head region. These larvae are found in various species of flatworms, including tapeworms and flukes. They undergo metamorphosis to develop into adult flatworms.
10.
Concentration of sense organs creates a _____ and needs a ____
Correct Answer
head brain
head cerebral ganglia
antero-posterior axis
head ganglion
Explanation
The concentration of sense organs in the head indicates that the head is the main sensory center of an organism. The brain, which is located in the head, is responsible for processing and interpreting sensory information. The term "head cerebral ganglia" refers to a cluster of nerve cells in the head that function as a primitive brain. The "antero-posterior axis" refers to the front-to-back orientation of the head, which is important for coordinating sensory input. "Head ganglion" refers to a collection of nerve cell bodies in the head that also play a role in sensory processing.