Summarization The larvae of each phylum of invertebrates are summarized.

Sponge phylum Calcareous sponge bicystic larvae, common sponge solid embryo larvae.

Coelenterate phylum Hydra splanktonic larvae.

Annelida, phylum Polychaete basilica larvae (seafood).

The molluscs are polychaetes, pods, and disc larvae.

Arthropod phylumlopoditorophyllum trilobite larvae.

Answer]: Recommended.

Analysis: Amphibian spine is divided into cervical vertebrae, torso vertebrae, recommended vertebrae and caudal vertebrae. There is more differentiation of cervical vertebrae and recommended vertebrae than fish, fish have no cervical vertebrae, and the head can not rotate, and the differentiation of amphibian cervical vertebrae makes the head rotate slightly, but there is only one cervical vertebrae, which is a transitional stage slow eggplant segment.

The limbs of landed amphibians are subject to weight, and in connection with this, there is a differentiation of the vertebrae in the spine, but there is only one piece. Fish even fins do not bear weight, the girdle does not meet the spine, and the spine does not have vertebrae differentiation. In early amphibian fossils, the girdle is also not attached to the spine, so there is no differentiation of the vertebrae.

Summary. Invertebrates are mainly grouped as follows: protozoa, flattened animals.

Invertebrates are mainly grouped as follows: protozoa, flattened animals.

Summary. Hello! Kiss, <>

I'm glad you asked to briefly describe the evolutionary characteristics and representative species of the main groups of invertebratesThe invertebrate refers to animals without a vertebral column, including many different organisms, the following are the evolutionary characteristics and representative species of their main groups: Sponges: have no tissues and organs, and are composed of a group of foramen cells.

Representative species include sponges and glass sponges.

The evolutionary characteristics and representative species of the main groups of invertebrates are briefly described.

Hello! Kiss, <>

I am glad that your question briefly describes the evolutionary characteristics and representative species of the main groups of invertebrates, which are invertebrates and do not have a vertebral column, including many different species of organisms, and the following are the evolutionary characteristics of their main groups and the representative species of the bend: Sponges: Structures composed of a group of foramen cells.

Representative species include sponges and glass sponges.

Hello! Kiss, <>

Invertebrates also have cnidarians: they have cnidarians, which can catch and kill their prey. Representative species include jellyfish, corals, and anemones.

Flattened: The body is flattened, with a distinct head and tail, and the digestive tract has only one mouth. Representative species include flukes and tapeworms.

Molluscs are like objects: the body is soft, has no hard bones, and usually has gastropods, cephalopods, or bivalves. Representative species include snails, clams, and octopuses.

Arthropods: The body is made up of many segments, with an exoskeleton and arthropods, often with sensory organs and compound eyes. Representative species include insects, spiders, and crabs.

The above major groups of invertebrates have their own unique evolutionary and biological characteristics. Their diversity and adaptability make them widely distributed in different ecosystems and are an indispensable part of the ecosystem.

This question is problematic, but it is one of the most frequently cited test questions.

Analysis: There are many animals with underdeveloped mouthparts, such as mollusks, which are also widely distributed, and obviously a is not.

There are also many animals with exoskeletons, such as crustaceans, and they have a wide distribution, so B is not selected.

Generally, there are two pairs of wings for the insect class winged subclass, the wingless subclass insects do not have wings, but they appear in the South Pole, where there happen to be no "winged subclass" insects, how do they go and how do they adapt to life there? Fish and molluscs do not have wings, and their distribution range is quite wide, so it is relatively difficult to choose C.

It is suitable for land life, and there are many insects in the water, such as insects of the family of bugs, bugs and dragonlice; Moreover, terrestrial animals are adapted to terrestrial life, and most of the animals classified at the class level do not necessarily have a large distribution range. So it's more reluctant to choose D.

Therefore, in terms of the four comparisons, it is probably only a little more reasonable to choose C.

In fact, the real reason for the wide distribution range of insects is that their survival strategy is the R-strategy, that is, to maintain the population advantage through a short generation cycle and a large number of eggs, so that in order to obtain living space, it will inevitably spread, and the spread will inevitably lead to a large distribution range, and the insects will be maximized through natural selection. Strictly speaking, our planet is the planet of arthropods, and insects are the most common among arthropods.

I choose CThe reason why insects have the most widespread distribution and the largest range of activity is that they have wings and can fly.

Insects generally have two pairs of wings and are the only invertebrates that can fly, which can expand the range of insect movement and distribution, which is beneficial for insects to find food, find mates, and escape predators.

Option B The body surface is protected by an exoskeleton.

Fish have tails without limbs, bifurcated tails, breathe with gills, live in water, oviparous animals, and have an unconstant body temperature.

Amphibians have tails and no limbs, and larvae breathe with gills and live in water. They live as adults on land or in water, have no tail and limbs, and breathe mainly with their lungs, and when in the water, they can breathe with **. Oviparous animals, the body temperature is not constant.

Common animals: frogs, salamanders, giant salamanders (salamanders), etc.

Reptiles ** have scales or nails on the surface, breathe with lungs, oviparous, live on land, and have an unconstant body temperature.

Common animals: tortoises, chameleons, crocodiles, etc.

Bird body shape characteristics: the body is spindle-shaped, the forelimbs are specialized into wings, the body surface has feathers, the body temperature is constant, the chest muscles are developed, the bones are healed, thin, hollow, and the brain is relatively developed. Oviparous animals.

They have beaks and no teeth, feathers on the surface of their bodies, and breathe with their lungs, and most of them are able to fly.

Common animals: ducks, pigeons, geese, parrots, etc.

Mammals have a coat all over their bodies, have a constant body temperature, are viviparous, lactate, and breathe with their lungs. Bats are.

Among mammals, it is the only animal that can fly.

Mammals are the most advanced of all animals.

The first mammals appeared about 200 million years ago, and they are currently the most widely distributed and well-functioning animals in the animal kingdom.

Species: Mainly include Protozoa, Porous Animals (Sponges), Coelenterates, Flattenses, Nematozoa, Molluscs, Annelids, Arthropodas, Echinoderms, and Hemichordates. There are many species of invertebrates, accounting for about 97 species in the animal kingdom, of which the phylum Arthropod is the first phylum and the mollusc phylum is the second phylum.

Characteristics: Protozoa: small body, simple structure, unicellular, multi-aquatic.

Coelenterates: body wall diderm, mouth but not anus, radially symmetrical.

Flattened animals: trigerm, mouth but not anus, symmetrical on both sides, hermaphroditic.

Nematoids: mouth and anus; The body is linear or cylindrical, unsegmented, with a cuticle on the body surface, and is mostly dioecious.

Annelids: oral and anal, cylindrical or flattened, segmented, with a true body cavity, with a relatively complete system.

Molluscs: mostly symmetrical, unsegmented, mantle and shell.

Arthropods: symmetrical on both sides of the body, no shells, body and appendages segmented, head, thorax and abdomen, chitinous exoskeleton, open tubular circulation, body cavity filled with blood.

Echinoderms: no shells, juveniles are symmetrical on both sides, adults are mostly radially symmetrical, with spinous protrusions on the body surface, gills breathing, tubular foot movement and predation, and mostly calcareous endoskeletons.

Answer B Because insects have wings and can fly from one place to another, they have a wide range of distribution and a wide range of activities.

Insects belong to the phylum Arthropods of the kingdom Animalia, and the generalized insect class, also known as the hexapod class, includes: Protocauda, Ectocera, Ditaila and Narrow Insecta. It is distinguished from other animals, especially other arthropods, by the following characteristics: the body is divided into cephalic, thoracic, and abdominal parts.

three body segments; The body is covered with a chitin exoskeleton; with 3 pairs of feet; If there are wings, it is generally two pairs. It should be noted that with the exception of Protocerda, other insects have antennae. Protocoptera, Cyclocada, Ditaila and Narrow Insecta are primitive wingless species; In addition, some groups in the class Narrow Insects have lost their wings in evolution, such as parasitic pests such as lice and tricocholia; Finally, for example, the hindwings of the order Diptera (mosquitoes, flies, etc.) evolved into a balanced list, and only a pair of membranous wings were visible.

I am an insect professional.