Question
The table shows the number of animals collected in a sample from a woodland and the groups to
which they belong.
How many arthropods in total, in this sample, have six or eight legs?
A 15 B 88 C 90 D 98
▶️Answer/Explanation
C
To determine the total number of arthropods with six or eight legs in the given sample, we need to consider the groups of animals mentioned. Insects are the only group that can have six legs, while crustaceans, arachnids, and myriapods can have more than six legs. Therefore, we can conclude that the arthropods with six legs are insects, and the ones with eight legs are arachnids.
Given that there are 10 arachnids and 80 insects in the sample, the total number of arthropods with six or eight legs is the sum of these two groups:
Total arthropods with six or eight legs = Number of arachnids + Number of insects = 10 (arachnids) + 80 (insects) = 90 arthropods
So, there are a total of 90 arthropods with either six or eight legs in this sample.
Question
Which group of organisms has the following features?
● three pairs of jointed legs
● three-part segmented body
● one pair of antennae
A arachnids
B crustaceans
C insects
D myriapods
▶️Answer/Explanation
C
The group of organisms that possesses the features of three pairs of jointed legs, a three-part segmented body, and one pair of antennae is option C: insects. Insects are characterized by these specific traits and represent the largest class within the phylum Arthropod. Insects have three pairs of legs, making a total of six legs. These legs are jointed, allowing for a wide range of movement. The body of an insect is divided into three distinct segments: the head, thorax, and abdomen. This segmentation provides flexibility and allows for specialized adaptations in different body regions. Insects typically have one pair of antennae on their head. Antennae serve as sensory organs, enabling insects to detect chemical signals, touch, and environmental cues.
Arachnids (option A) have four pairs of jointed legs, while crustaceans (option B) typically have more than three pairs of legs and a more complex body structure. Myriapods (option D) have numerous legs and a segmented body, but they usually possess more than three pairs of legs.
Question
The table shows some characteristics of four different vertebrates.
Which vertebrate is a reptile?
▶️Answer/Explanation
B
Based on the provided characteristics, the vertebrate that fits the description of having absent fins and hair, but present legs and scales is a reptile. Reptiles are a diverse group of cold-blooded vertebrates that belong to the class Reptilia. They are characterized by several key features, including scaly skin, amniotic eggs, the ability to breathe air, legged locomotion, and lack of hair or fur. They have dry, scaly skin that helps protect them from water loss and external injuries. Some common examples of reptiles include snakes, lizards, turtles, and crocodiles. They exhibit a remarkable variety in size, shape, color, and habitat preferences.
Question
Which characteristics do bony fish have?
▶️Answer/Explanation
C
Bony fish, also known as osteichthyans, are a diverse group of fish species that make up the largest class of vertebrates, the Osteichthyes. They possess several characteristics that distinguish them from other types of fish. Bony fish have a well-developed internal skeleton with a backbone composed of vertebrae. The backbone provides structural support and protects the spinal cord. They also have scales covering their body. These scales are composed of a bone-like material called ganoid, cycloid, or ctenoid scales, which provide protection from predators and abrasions. The type of scales varies between different species of bony fish. Unlike mammals, bony fish lack hair or fur. Instead, they have smooth and often slimy skin that helps reduce drag and provides protection against parasites.
Question
The diagram shows a sea lion.
Which labelled feature shows that this animal is a mammal?
▶️Answer/Explanation
D
The presence of whiskers on a sea lion indicates that it is a mammal. Whiskers, also known as vibrissae, are specialized sensory hairs found in various mammals, including sea lions. Whiskers are longer and stiffer than regular fur and are usually found around the muzzle or face of mammals. They are rooted deeply in the skin and are rich in nerve endings, making them highly sensitive to touch and vibrations in the surrounding environment.. They play a crucial role in tactile sensing, assisting in navigation, detecting prey, and assessing the environment. Whiskers are unique to mammals and are not found in other animal groups such as reptiles or birds. Therefore, the presence of whiskers on a sea lion is a clear characteristic of its mammalian nature.