<span>Invertebrate<span>, </span>any animal that lacks a vertebral column, or backbone, in contrast to the cartilaginous or bony vertebrates. More than 90 percent of all living animal species are invertebrates. Worldwide in distribution, they include animals as diverse as sea stars, sea urchins, earthworms, sponges, jellyfish, lobsters, crabs, insects, spiders, snails, clams, and squid. Invertebrates are especially important as agricultural pests, parasites, or agents for the transmission of parasitic infections to humans and other vertebrates. Invertebrates serve as food for humans and are key elements in food chains that support birds, fish, and many other vertebrate species.Apart from the absence of a vertebral column, invertebrates have little in common. Indeed, they are distributed between more than 35 phyla. In contrast, all vertebrates are contained within a single phylum, the Chordata. (Phylum Chordata also includes the sea squirts and some other invertebrate groups.) Invertebrates are generally soft-bodied animals that lack a rigid internal skeleton for the attachment of muscles but often possess a hard outer skeleton (as in most mollusks, crustaceans, and insects) that serves, as well, for body protection.</span>
It has been projected that by 2025 b. 2 out of 3 people will suffer from water shortages.
The problem of shortage of water will happen to the altered weather patterns, depletion of ground water, pollution of water, and due to demand-supply problem in increased population sizes of humans. The present scenario is emphasizing more on the sustainable use of water for agricultural and industrial purposes to promote water conservation. This will reduce the proportion of affected people in the future.
Answer: B. the pH in the stomach is not suitable for the amylase to work.
Explanation: When carbohydrates reach the stomach no further chemical breakdown occurs because the amylase enzyme does not function in the acidic conditions of the stomach.
