Need help with these---
14. Which of the following is present in an insect but not in arachnids?
a. mandibles
b. compound eyes
c. jointed appendages
d. segmentation
16. The exoskeleton of an insect
a. does not have any muscles attached to it
b. is moved by muscles that are attached to the inside of the exoskeleton
c. is thickest where the joints of the appendages are located
d. is moved only by muscles attached to the wings
-MC
Sure, I can help you with these questions.
14. To determine which of the given options is present in an insect but not in arachnids, we need to compare the characteristics of insects and arachnids. Insects are a type of arthropod characterized by having three main body segments (head, thorax, abdomen) and six legs, in addition to other specific features. Arachnids, on the other hand, have two main body segments (cephalothorax, abdomen) and four pairs of legs.
a. Mandibles: Both insects and arachnids have mandibles, so this is not the correct answer.
b. Compound eyes: Insects have compound eyes, while arachnids have simple eyes or no eyes at all. Therefore, compound eyes are present in insects but not in arachnids.
c. Jointed appendages: Both insects and arachnids have jointed appendages, so this is not the correct answer.
d. Segmentation: Both insects and arachnids are segmented organisms, so this is not the correct answer.
Therefore, the correct answer is: b. compound eyes.
16. To determine the correct answer regarding the exoskeleton of an insect, we need to understand its structure and how it functions. The exoskeleton of an insect is a rigid external covering that provides support and protection to its body.
a. Does not have any muscles attached to it: This is incorrect. Muscles are attached to the inside of the exoskeleton and are responsible for the movement of the insect's body parts.
b. Is moved by muscles that are attached to the inside of the exoskeleton: This is the correct answer. The muscles inside the exoskeleton contract and relax to enable movement.
c. Is thickest where the joints of the appendages are located: This is incorrect. The exoskeleton is usually thicker at the body segments rather than at the joints.
d. Is moved only by muscles attached to the wings: This is incorrect. While muscles attached to the wings play a role in wing movement, other muscles attached to the exoskeleton control the movement of other body parts.
Therefore, the correct answer is: b. is moved by muscles that are attached to the inside of the exoskeleton.
15. Spiders have simple eyes, up to eight of them.
16. b.