How does the head of a grasshopper compare to a crayfish? b. What are the palps used for? c. What structures on a crayfish serve a similar function to a grasshopper? d. Spiracles can be opened or closed. Why does an insect need to close its spiracles? 2. What features do the Hymenoptera insect, Isoptera insect, and Diptera insect have in common? How are they different? What is the number of species for each? 3. How would a polychaete survive in the wild? What would they need to adapt to, to help them survive? 4. Describe four adaptations that make Loligo a highly effective predator, compared to more primitive mollusks.
The Correct Answer and Explanation is:
Comparing the Head of a Grasshopper and a Crayfish:
The head of a grasshopper and a crayfish both serve to house sensory organs, but they have distinct features due to differences in their environments and lifestyles. A grasshopper’s head is smaller, with compound eyes, antennae, and specialized mouthparts for biting and chewing. In contrast, a crayfish has a larger head with compound eyes, antennae, and mandibles designed for handling food in an aquatic environment. Grasshoppers are terrestrial, while crayfish are aquatic, which influences the structure of their head and sensory adaptations.
b. The Function of Palps:
Palps are appendages found on the heads of both grasshoppers and crayfish. In grasshoppers, the palps are located near the mouthparts and are used for sensing and manipulating food. In crayfish, the palps are involved in touch and taste, helping the animal locate and handle food in its aquatic environment.
c. Similar Structures in Crayfish and Grasshoppers:
Both have antennae that serve similar functions of detecting changes in their environment, such as vibrations, chemicals, and temperature. While grasshoppers use their antennae for sensory information, crayfish use theirs for touch and chemoreception, necessary for survival in the water.
d. Why Spiracles Need to Be Closed in Insects:
Spiracles are openings on the exoskeleton of insects that allow air to enter for respiration. Insects need to close their spiracles to prevent water loss, as they often live in dry environments where conserving moisture is essential. Closing the spiracles also helps protect the insect from harmful microorganisms and pollutants.
Hymenoptera, Isoptera, and Diptera Common Features:
These three orders of insects share several features, including the presence of three body segments (head, thorax, and abdomen), six legs, and wings in many species. They all undergo metamorphosis.
- Hymenoptera (e.g., bees, ants, wasps) are known for their social structure, often with a division of labor.
- Isoptera (termites) also exhibit social behavior, but their primary focus is on decomposing plant matter, particularly wood.
- Diptera (flies, mosquitoes) have a single pair of wings and undergo complete metamorphosis.
The number of species for each is vast:
- Hymenoptera: Around 150,000 species
- Isoptera: Approximately 3,000 species
- Diptera: Around 120,000 species
Polychaetes in the Wild:
Polychaetes are marine worms that live in various environments, including the seafloor and in burrows. To survive, they must adapt to fluctuating water conditions, temperature variations, and the availability of food. Polychaetes are generally scavengers or predators, requiring adaptations like specialized bristles (setae) for locomotion and capturing prey. They also need to avoid predators and adapt to changing oxygen levels in their environments.
Loligo’s Predatory Adaptations:
Loligo, or squid, has several adaptations that make it a highly effective predator:
- Jet propulsion allows fast movement through water, enabling it to chase down prey.
- Complex eyes with excellent vision help it detect prey in low light conditions.
- Tentacles equipped with suckers provide a strong grasp on prey.
- Camouflage abilities through chromatophores and iridophores help it blend into its environment and avoid predators.
These adaptations are more advanced compared to more primitive mollusks, which may lack specialized locomotion, complex eyes, or efficient camouflage.
