Accumulation of common sense in Shanxi Province: The Main Taxa of Animals (Part 1)

　　The range of common sense judgment test points is very wide, generally including politics, law, economy, humanities, geography, science and technology, life, etc., which requires the long-term uninterrupted accumulation of small partners. The common sense related test point brought to you today is "the main taxon of animals (part 1)".

　　The main group of animals

　　According to the invertebrates of the animal body, it can be divided into: vertebrates and invertebrates.

　　invertebrate

　　Invertebrates are dorsal animals without a spine, including echinoderms, molluscs, spiny animals, arthropods, sponges, linear animals, and cephalopods and tail cords of the chordate phylum. The number of species accounts for 95% of the total number of animal species and is the original form of animals.

　　1. Coelenterates and flat animals

　　Most species of coelenterates live in the ocean, such as jellyfish, anemones, jellyfish, polyps, etc.; a few live in freshwater, such as hydras.

　　The main characteristics of coelenterates are: the body is radiatively symmetrical; the body surface has thorn cells; and the mouth does not have anus.

　　Flat animals are a simple symmetrical animal with no links on both sides, with three germ layers, no body cavity, no respiratory system, no circulatory system, and no mouth and no anus. Therefore, it must keep the body flat so that oxygen and nutrients can be absorbed through infiltration. Representatives of flat animals are tapeworms, schistosomiasis and planarians.

　　2. Linear animals and link animals

　　Linear animals are a phylum of parasites in proto-mouth animals with prosthetic cavities, but adults have no excretory organs and the digestive tract degenerates. Common nematodes are parasites such as roundworms, pinworms, and hookworms.

　　The main characteristics of linear animals: the body is elongated and cylindrical; the body surface has a stratum corneum; there is a mouth and anus.

　　The link animals are symmetrical, co-rhythmic cleavage cavity animals on both sides, some with warty feet and bristles, multi-closed tube circulatory system, chain nervous system. Common animals are: earthworms, earthworms (also known as leeches), sand silkworms and so on.

　　3. Mollusks and arthropods

　　Molluscs are invertebrates, and molluscs have a large number of members, such as snails, river mussels, conchs, squid and other species.

　　Most molluscs have shells, such as snails, clams and other shellfish; a few on land have snails and slugs; the shells of octopuses, squids, and sea slugs have disappeared; most mollusks rely on a fleshy foot to slide forward to move their bodies, and many have a coiled shell to protect the soft body inside.

　　Arthropods are composed of exoskeletons such as insects and arachnids, and in addition to insects, common shrimps, crabs, spiders, centipedes and extinct trilobites are arthropods.

　　All arthropods have the following key characteristics:

　　1. The body is symmetrical left and right (there will be no more structures such as snails and starfish);

　　2. It is divided into three sections: head, chest and abdomen, but it may be that the head and chest are combined into the cephalothorax, or the chest and abdomen are combined into the trunk;

　　3. Appendages and segments, which is why arthropods get their name;

　　4. There are exoskeletons formed by several dice on the surface of the body, which can play a protective role in the body. However, because the exoskeleton does not have growth, arthropods will have the behavior of shelling;

　　5. Invertebrates other than arthropods, the muscles are smooth muscles (our intestinal wall is smooth muscles), the contraction rate is slow, and it takes a few seconds to move; while the muscles of arthropods are striated muscles (our limbs are striated muscles), which can move several times a second, greatly improving their motor ability (so insects are so agile).

　　Source: National Zoological Museum

　　Brush question consolidation

　　1. Regarding "praying mantis catching cicadas, yellow finches in the back", the following statement is wrong ( )

　　A. Cicadas, praying mantises and yellow finches are all consumers

　　B. The behavior of praying mantises and yellow finches is congenital

　　C. Mantises, cicadas and yellow finches form an ecosystem

　　D. Cicadas and praying mantises belong to arthropods, and yellow finches belong to birds

　　【Analysis】C. The first step is to look at the way you ask questions. This question is a non-selective question that examines biology.

　　The second step is to identify the options.

　　Item A: Correct. The scientific definition of the consumer: a link in the food chain, represents a creature that cannot produce, but can only achieve self-survival by consuming other organisms. Cicadas, praying mantises and yellow finches are all consumers.

　　Item B: Correct. Innate behavior is determined by the genetic material in the animal's body, and it is an innate instinct that does not require acquired learning. For example: honey bees collecting honey, ants building nests, spider webs weaving, bird migration, etc.

　　Item C: Error. The components of ecosystems include abiotic matter and energy, producers, consumers, and decomposers. Among them, the producer is the main ingredient. Praying mantises, cicadas and yellow finches are all consumers and cannot form an ecosystem.

　　Item D: Correct. Arthropods are symmetrical on both sides of the body, composed of a column of body segments, heterogeneous segments, can be divided into three parts of the head, chest, abdomen, or the head and chest heal into the cephalothorax, or the chest and abdomen heal into the trunk. Cicadas and praying mantises belong to arthropods, and yellow finches belong to birds.

　　Therefore, for this question, choose option C.