Question

The polysaccharide that forms the hard outer covering of many invertebrates is a. collagen. b. chitin. c. chondroitin sulfate. d. pectin. e. cellulose.

Short answer

The polysaccharide that forms the hard outer covering of many invertebrates is chitin.

Step-by-step solution

Recognize The Question's Context

Before picking an answer, acknowledge that invertebrates are organisms that do not possess a vertebral column. The question is looking for the polysaccharide, a carbohydrate, that forms their hard outer covering.

Understand Polysaccharides

Polysaccharides are long chain carbohydrates that can have structural or storage functions in different organisms. Understanding this definition helps to figure out the correct answer among the available options.

Match Polysaccharide with Function

Now we match the polysaccharides given in the options with their known roles or functions. According to general knowledge in Biology, chitin is a polysaccharide known to form hard and protective structures in invertebrates, especially in arthropods like insects and crustaceans. So, the correct answer is 'chitin'.

Key concepts

Understanding Chitin

Chitin is a fascinating substance found in the animal kingdom. It is a complex carbohydrate, classified under the group of biopolymers known as polysaccharides. Considered the second most abundant biopolymer after cellulose, chitin serves as a critical component in the exoskeletons of arthropods, such as insects, spiders, and crustaceans.

Chitin provides these creatures with both protection and support, creating a hard and resilient outer shell. Structurally, it is composed of repeating units of N-acetylglucosamine, a modified sugar. This arrangement results in a tough yet flexible material that can withstand physical stress. An interesting fact about chitin is that, although it is rigid, it allows for growth through the process of molting, where the invertebrate sheds its old exoskeleton and forms a new, larger one. This is crucial for their development and survival.

Moreover, chitin has also found various applications in the biomedical field, agriculture, and as an eco-friendly bioplastic, owing to its biodegradability and non-toxic nature. The study of chitin not only helps in understanding invertebrate anatomy but also opens doors to innovative applications beneficial to humans.

Biological Molecules and Their Functions

Biological molecules, collectively known as biomolecules, play vital roles in maintaining life's processes. These molecules include carbohydrates, proteins, lipids, and nucleic acids - each with unique functions.

Carbohydrates, such as polysaccharides, provide energy storage and structural support in organisms. Proteins serve a wide array of functions from catalyzing biochemical reactions as enzymes to providing structural integrity and signaling between cells. Lipids are the main components of cell membranes and serve as long-term energy reserves. Lastly, nucleic acids like DNA and RNA are the molecules of heredity and are responsible for storing and transmitting genetic information.

Understanding these molecules is key to studying not only invertebrate anatomy but also the vast complexity of life itself. As the building blocks of organisms, they are intricately related to every aspect of biology, from tiny cellular processes to the entire ecosystem.

Invertebrate Anatomy and Polysaccharides

Invertebrate anatomy, unlike that of vertebrates, does not include bones for structural support. Instead, many invertebrates rely on exoskeletons made from polysaccharides such as chitin.

These exoskeletons not only provide protection against predators and physical damage but also play a role in locomotion, as muscles attach to the internal surfaces and exert force against the rigid structure. The diversity in invertebrate anatomy is remarkable, with variations in exoskeletons found among different species leading to a wide range of adaptations that suit their ecological niches.

Additionally, understanding the role of polysaccharides in invertebrates is critical not just for biology students but also for the fields of material science and engineering. This is because the mechanical properties of these natural composites can inspire the design of new materials. Hence, the study of invertebrate anatomy and its connection to polysaccharides like chitin illuminates a crucial intersection between biology and technology.