Chapter 1 Animals in Different Environments

1. At present, there are about1.50,000 known species of animals.

2. Animals can be divided into two categories: one is vertebrate and the other is invertebrate. The difference between the two is whether the body has a spine (note: don't write spine as spine).

3. Fish can live in water with two main characteristics: one is to get food and defend against enemies by swimming, and the other is to breathe in water.

4. The body of crucian carp is spindle-shaped, which is beneficial to reduce the resistance of water movement.

5, fish live in water, which can make fish float, dive and stay in a certain water layer.

6. When a fish swims, it relies on the left and right swinging of its trunk and tail fin to generate the power to move forward; It relies on pectoral fin, ventral fin and dorsal fin to keep balance; And it relies on the caudal fin to maintain and determine the direction of progress and generate the power of progress.

7. When it is difficult to experiment directly with the research object, sometimes the model is used to do the experiment, that is, to imitate the experimental object to do the model or to imitate some conditions of the experiment. Such an experiment is called a simulation experiment.

8. The mouth of live crucian carp and the trailing edge of gill cover alternately open and close, that is, breathing.

9. The color of gills is bright red, because there are rich blood vessels.

10, gill filaments are many and thin, which can enlarge the contact area between gill and water and is beneficial to breathing.

1 1. Water flows into the gills from the fish mouth, and then flows out from the back edge of the gill cover, during which breathing (i.e. gas exchange) takes place. The process is that when the water flows through the gill filament, the dissolved oxygen in the water enters the blood vessels of the gill filament, and the carbon dioxide is discharged into the water from the gill filament, so the oxygen in the water flowing out through the gill filament decreases and the carbon dioxide increases.

12, fish gills are rich in blood vessels and many thin gills, which are very important for fish to breathe in water.

13, the main characteristics of fish: the body surface is often covered with scales, through gill breathing, through the swing of trunk and tail fin and the coordinated swimming of fins, they live in water all their lives.

14. Anemones, jellyfish, corals and other animals belong to coelenterates. Their main feature is that there is a digestive cavity in the body, with a mouth and no anus, and food residues are discharged through the mouth.

15, squid, octopus, mussel, squid, moth snail, etc. It belongs to mollusks, mainly characterized by soft body, shell (which can protect the body) or shell degradation.

16. Shrimp and crab are called crustaceans, and they have hard armor on their bodies.

17, coelenterates, mollusks and crustaceans all belong to invertebrates.

18. Dolphins, whales and seals belong to mammals, turtles belong to reptiles, and mammals and reptiles belong to vertebrates.

19. Characteristics of animals adapting to land life: ○ 1 Generally, there are structures to prevent water loss, such as snakes with scales and insects with exoskeletons; ○0 generally has organs supporting the body and movement, which are used for foraging and avoiding enemies in various sports modes; ○3 Except for earthworms and other animals, there are generally various respiratory organs located in the body that can breathe air, such as locusts breathing through trachea and rabbits breathing through lungs; ○4 Generally, it has developed sensory organs and nervous system, and can cope with the changing environment in time.

20; The experiment of observing earthworms: ○ 1 Earthworms distinguish the front end from the back end by the girdle, and the end near the girdle is the front end. There are 13 knots from the earthworm's head to the belt. ○2 Touching the ventral surface of earthworms with your hands will give you a rough feeling. This is because you are in contact with bristles, which are used to support your body and assist in exercise. ○3 Earthworms move flexibly and quickly on rough paper, because the cooperation of muscles and bristles makes the body crawl; Earthworms move hard and slowly on the glass plate because the bristles have lost their function. ○4 During the experiment, attention should be paid to keeping the earthworm body wall moist all the time, because the earthworm relies on the moist body wall to complete breathing.

The body is composed of many annular segments, and such animals are called annelids.

Earthworms live in humid soil rich in humus.

22. Earthworms lie down during the day and come out at night, feeding on dead leaves, rotten roots and other organic substances.

23. After the rainstorm, the earthworm will climb to the ground, because the rain will crowd out the air in the soil, and the earthworm will be forced to climb to the surface to breathe.

24. Earthworms, leeches and nereis all belong to annelids, because their bodies are composed of many joints (which is also the main feature of annelids). Body segmentation can make the body move flexibly.

25. The reason why the rabbit's body temperature is constant: ○ 1 The body surface is covered with hair, which has the function of heat preservation; ○2 Strong gas exchange ability of respiratory system; ○3 There is a perfect circulation system with strong oxygen transport ability; ○4 There is a developed nervous system, which can maintain a constant body temperature through adjustment.

They can keep their body temperature constant by self-regulation. They are all warm-blooded animals. The body temperature of other animals will change with the change of the surrounding environment, and they belong to temperature-changing animals.

26. The blood circulation of rabbits includes systemic circulation and pulmonary circulation. The ability to transport oxygen is strong, which is beneficial to the decomposition of organic matter and provides enough energy for the body.

27. Mammals and birds belong to warm-blooded animals, while other animals belong to warm-blooded animals.

28. Rabbit's teeth are divided into incisors and molars. Front teeth are used to cut off food, and molars are used to grind food. This is in line with the habit of eating plants and belongs to herbivores.

29. The teeth of tigers and wolves are divided into incisors, molars and canine teeth. Canine teeth are developed, used to tear food, adapted to the living habits of edible animals, and belong to carnivores.

30. Rabbits have a long digestive tract and a developed cecum, which is suitable for rabbits to eat plants.

3 1. Rabbits have developed brains and nerves all over their bodies, which makes them sensitive to changes in the external environment.

32. The main characteristics of mammals: hair on the body surface, viviparous, breastfeeding and tooth differentiation.

There are more than 9000 kinds of birds in the world.

34. The significance of flying: ○ 1 expanded the scope of activities; ○2 Conducive to foraging and reproduction.

35. The feathers used by birds for flying are normal feathers, which are distributed on the surface of the body and the surfaces of the wings, and the wings are the most. Their structural characteristics are: hard shaft and flat feathers.

36. Birds have well-developed pectoral muscles, which affect the two wings to complete flight movements.

37. There is a keel on the sternum of domestic pigeons, which is used to develop the pectoral muscles.

38. Birds often excrete feces. The reasons are: ○ 1 The digestive system is developed, and the feces are digested, absorbed and excreted quickly; ○2 The rectum is very short, and feces are not stored in the body (which is conducive to weight loss).

39. There are many pairs of well-developed air sacs in birds, one end of which is connected with the lung, which are distributed between internal organs, and some of them extend into the bone cavity. Its function is to temporarily store gas and help breathing.

40. Every time a bird breathes, it exchanges gas twice, both of which are in the lungs.

4 1, the characteristics of birds suitable for flight: the bird's body is streamlined, which can reduce the resistance during flight; The body is covered with feathers; Have wings that can fly; The pectoral muscles are developed; The sternum has a keel-like process and the long bone is hollow; Developed digestive system, rapid digestion, absorption and excretion of feces; The circulation system has perfect structure and strong function of transporting nutrients and oxygen; There is a unique airbag that can help breathing.

42. The main characteristics of birds: the body surface is covered with feathers, the forelimbs become wings, and they have the ability to fly quickly; The car body has airbags; Body temperature is high and constant.

43. Insects are the most diverse animals, with more than 6,543,800 known species.

44. Insects are the only flying animals among invertebrates.

45. Insects have strong athletic ability, because insects have three feet and can crawl; Some insects' feet are specialized into jumping feet, which can jump; Most insects have wings and can fly.

46. The place where locusts exchange gas is between tiny trachea and cells.

47, the main characteristics of insects; The body is divided into three parts: head, chest and abdomen, and the moving organs-wings and feet are born in the chest. There are developed muscles in the chest, which are attached to the exoskeleton.

48. The function of exoskeleton: ○ 1 protect and support internal soft tissues; 2 prevent evaporation of water in the body.

49. Insects, spiders, centipedes, shrimps and crabs all belong to arthropods; * * * Same features: The body consists of many body segments; There is an exoskeleton on the body surface; The foot and antenna are segmented.

Frogs and toads in vertebrates belong to amphibians. Their main characteristics are: larvae live in water and breathe with their gills, which are called tadpoles. Tadpoles develop into frogs after metamorphosis, and then live an amphibious life, breathing with lungs and skin.

5 1. The places where amphibians exchange gas are lungs and skin.

52. March 22nd, World Water Day.

Adequate food and water are basic environmental conditions (animals live on land).

Chapter II Animal Movement and Behavior

1. The activities that animals carry out are conducive to survival and reproduction, which are often manifested in various sports.

2. The motor system of mammals consists of bones and muscles.

3. Bones play a lever role in sports; Joints play the role of fulcrum in movement; Skeletal muscle plays a dynamic role in exercise.

4. Joints are generally composed of articular surface, articular capsule and articular cavity. The articular surface is composed of articular head and articular fossa, and there is a layer of articular cartilage on the surface of the articular surface.

5. The joints are firm and flexible, and the structures that make the joints move flexibly are articular cartilage and synovial fluid, and articular cartilage can reduce the friction between bones; The structure that makes the joint firm is the joint capsule and ligament.

6. Skeletal muscle consists of muscle abdomen and tendon, and the thicker part in the middle is muscle abdomen, which can contract; The thin milky parts at both ends are tendons, which can be attached to different, two or more bones.

7. Skeletal muscles must span one or more joints.

8. Skeletal muscle has the characteristics of stimulated contraction.

9. When skeletal muscle is contracted by nerve stimulation, it will affect the movement of bones around joints, so the body will move.

10, the completion of an action requires at least two or more muscle groups to cooperate with each other under the control of the nervous system.

1 1. When the elbow is flexed, the biceps brachii muscle group contracts and the triceps brachii muscle group relaxes. When the elbow joint is straight, the triceps brachii muscles contract and the biceps brachii muscles relax; Hands droop naturally, biceps brachii and triceps brachii relax; Hands droop and lift water, and biceps brachii and triceps brachii contract.

12, exercise is not only completed by the exercise system, but also requires the supply of energy, the coordination of digestive, respiratory and circulatory systems, and the control and adjustment of the nervous system.

13, the significance of exercise to animals: it is conducive to foraging and avoiding enemies to adapt to the complex and ever-changing environment.

14. Animal behaviors are diverse, such as foraging behavior, defensive behavior, reproductive behavior, migration behavior, aggressive behavior, food storage behavior, social behavior and so on. With the example, you should be able to judge what kind of behavior the above belongs to. Note: Aggression is a struggle between animals of the same species.

15, from the way of behavior acquisition, animal behavior can be divided into two categories: innate behavior and learning behavior. The behavior born and determined by genetic material is congenital behavior; On the basis of genetic factors, providing the role of environmental factors, the behavior obtained from life experience and learning is learning behavior.

16, newborn kangaroos climb into the pouch to feed, and American cardinals who have lost their chicks feed goldfish, which is an innate behavior; Earthworms walk a maze, tits steal milk, and chimpanzees grab food. These are all learning behaviors.

Animals with social behaviors include ants, bees, termites, monkeys, baboons, sheep, elephants and deer.

18, social behavior characteristics: certain organizations are formed within the group, members have a clear division of labor, work together, and some even form a hierarchical system. There are female ants, male ants, worker ants and soldier ants in the termite colony. Female ants lay eggs and breed offspring; It is soldier ants who defend the nest; Worker ants build nests and feed female ants, male ants and soldier ants; Males mate with females full-time.

20. In the "hierarchical society" composed of alpine baboons, according to the size, strength, health and fierceness of individuals, they are arranged in hierarchical order, with the most fierce and strong male baboon as the leader.

2 1. The right of a male baboon as a leader: give priority to food and mate, give priority to nesting sites, and other members show obedience to it and dare not fight back when attacking it; Responsibility: Be responsible for directing the actions of the whole community and defending this group together with other male baboons.

22. Animal movements, sounds, smells, etc. Can convey information (for example, you should be able to judge which of the above situations belongs to).

23. An ant returns to its nest after finding food. Other ants can find food by the smell of secretions.

24. After sensing the smell of sex pheromones secreted by the same kind of female insects through the olfactory receptors on the antennae, the male of the butterfly moth will fly over to mate with the female insects. Therefore, using extracted or synthetic sex pheromones as attractants can trap and kill agricultural pests.

25. The animals in the group send some information to other individuals, and the individuals who receive the information have some behavioral reactions. This phenomenon is called communication.

Chapter III The Role of Animals in the Biosphere

1, American science writer Rachel? Ge Xi published the book Lonely Spring on 1962.

2. The food chain consists of producers and consumers, which reflects the relationship between eating and being eaten.

3. In an ecosystem, multiple food chains are intertwined to form a food web.

4. There are interdependent and restrictive relationships between the food chain and various organisms in the food web.

5. In the ecosystem, the number and proportion of all kinds of organisms are always maintained in a relatively stable state (increase or decrease). This phenomenon is called ecological balance, which is a dynamic balance.

6. Humans can't kill an animal at will, because it will affect the survival of other creatures, thus affecting the ecosystem where animals live and destroying the ecological balance.

7, in the ecosystem, the number of all kinds of animals can't grow indefinitely, because ○ 1 When the number of an animal increases, the number of animals that feed on it will also increase; ○2 The space and food needed for survival are limited.

From the ecological point of view, people's production activities must be carried out in accordance with ecological laws.

9. Animals can promote the material circulation of the ecosystem, which means: ○ 1 Animals feed on organisms, digest and decompose organic matter in the body, release energy, and discharge carbon dioxide, urine, etc. And return to nature; ○2 The feces and remains of animals decompose, and the carbon dioxide formed returns to nature.

10, the role of animals in nature: ○ 1 maintaining ecological balance; ○2 Promote the material circulation of the ecosystem; ○3 Help plants pollinate and spread seeds.

1 1. Using biology as a "workshop" to produce some substances needed by human beings is called a bioreactor. The most ideal bioreactor in animals is the mammary gland bioreactor, that is, human beings can produce and secrete some substances that people need by transforming the genetic genes of an animal.

12. The key technology to make organisms into bioreactors is to transform their genes.

13. the advantages of using bioreactor to produce substances needed by human beings are: ○ 1 can save the cost of building factories and purchasing instruments and equipment; ○2 It can reduce complicated production procedures and environmental pollution; ○3 It can save a lot of land resources for building factories and can be used for greening and beautifying the environment.

14, bionic is to imitate some structures and functions of organisms (animals, plants, microorganisms, etc.). Invent and create all kinds of instruments and equipment. Such as: fireflies and luminescence, echolocation and radar of bats, crustaceans and thin-shell buildings of turtles.

15. By modifying the genetic genes of some animals (such as cattle and sheep), the breasts of these animals can produce and secrete some substances that people need.

Chapter IV Widely Distributed Bacteria and Fungi

1, an aggregate visible to the naked eye formed by bacteria or fungi after reproduction, is called colony. (Note: All bacteria or fungi in the colony are the same kind of bacteria or fungi).

2. Bacterial colony characteristics: the colony is small, and the surface is smooth, sticky or rough and dry.

3. Fungal colony characteristics: colonies are generally large, loose, fluffy, flocculent or cobweb-like, and generally appear in different colors such as red, brown, green, black and yellow.

4. General method of cultivating bacteria or fungi: First, a culture medium containing nutrients should be prepared, and the prepared culture medium should be sterilized at high temperature and cooled before use. The process of putting a small amount of bacteria or fungi into the culture medium is called inoculation. Usually, the inoculated Petri dishes are placed in a constant temperature incubator, or they can be cultured in a warm place indoors.

5. Petri dishes and culture media used for culture must be treated at high temperature before inoculation. Its purpose is to kill the spores of bacteria and fungi mixed in Petri dishes and culture media, and to discharge the pollution of other environments outside the experiment.

6. Bacteria or fungi can be found in soil, water, air, animals and plants, cold polar regions and hot hot springs, which shows that bacteria and fungi are widely distributed.

7. Conditions for the survival of bacteria and fungi: moisture, suitable temperature, organic matter (i.e. nutrition), some need oxygen, and some don't.

8./kloc-in the second half of the 0/7th century, Levin, the Netherlands? Hooke made a microscope with a magnification of 200-300 times and observed bacteria for the first time.

9. The French scientist Pasteur designed an experiment, which proved that the spoilage of broth was caused by bacteria in the air, and denied the view that bacteria naturally occurred. Later generations called him "the father of microbiology".

10, Pasteur put forward the pasteurization method for preserving wine and milk, and its content is high temperature sterilization.

1 1, the individual of bacteria is very small, which can only be observed by high-power microscope or electron microscope.

12, bacteria have different forms such as rod, ball and spiral.

13. Bacteria are unicellular organisms, and each bacterium lives independently.

14, bacterial cell structure consists of cell wall, cell membrane, cytoplasm and DNA (unformed nucleus). Some bacteria still have capsules or flagella, while others do not.

15, the structural characteristics of bacteria: it has a cell wall, no nucleus and chloroplast, and it has genetic material-DNA.

16. The main difference between bacteria and animal and plant cells is the unformed nucleus.

17, most bacteria are heterotrophic, because there is no chloroplast, they can only live by using ready-made organic matter and decompose organic matter into simple inorganic matter. The nutrition of some bacteria is autotrophic.

18, the propagation mode of bacteria is division propagation, and the number of bacteria formed is 2nm (m is the number before division and n is the number of bacteria continuously divided).

Some bacteria can form spores. The spore cell wall is thickened, and the individual is small and light, which can be scattered with the wind and germinate into bacteria in a suitable environment. Spore is a dormant body of bacteria and has strong resistance to adverse environment. A spore can only form one bacterium. Some bacteria cannot form spores.

20. The steamed bread is rotten and moldy, and the fruit grows "Mao Mao", which is the mold in fungi.

2 1, the main characteristics of fungi: ○ 1 unicellular (yeast) and multicellular (mold, mushroom); ○2 There are formed nuclei in the cells; ○3 can produce spores, which can develop into new individuals, that is, spore reproduction; ○4 There is no chloroplast, and the nutrition mode belongs to heterotrophy.

22. The difference between Penicillium and Aspergillus is that Penicillium is turquoise (because spores are turquoise) and hyphae with spores are broom-shaped; Aspergillus is black, yellow, brown and green, and the hyphae with spores are radial.

23. In the early morning or after rain in summer and autumn, mushrooms are easily picked on wet tree trunks or grass. This shows that fungi are suitable for living in a warm, humid and organic-rich environment.

24. Brewing, making bread and steaming steamed bread are all inseparable from yeast.

25. The difference between yeast and bacteria is that they have a shaped nucleus.

26. Mushroom spores grow on the wrinkled surface.

Chapter V Functions of Bacteria and Fungi in Nature

1, Bacillus subtilis rotted pears and bananas.

2. Bacteria and fungi play the role of decomposers in the material cycle, decomposing organic matter in animal and plant residues into carbon dioxide, water and inorganic salts, which can be absorbed and utilized by plants and produce organic matter through photosynthesis. It can be seen that bacteria and fungi play an important role in the circulation of carbon dioxide and other substances (that is, most organic and inorganic substances).

3. As decomposers, some bacteria and fungi use the organic matter in the remains of dead animals and plants to survive, and the way of nutrition is saprophy in heterotrophy.

4. Some bacteria and fungi live in heterotrophs and live on living animals and plants and organic matter in human body, which leads to different diseases between animals and plants and human body.

5. Streptococcus can cause tonsillitis, scarlet fever, erysipelas and other diseases.

6. Cotton wilt, rice blast, wheat leaf rust and corn smut are all caused by fungi.

7. Two creatures live together, depend on each other and benefit from each other. Once separated, neither of them can live independently. This phenomenon is called * * *. Some bacteria and fungi are related to animals and plants.

Lichens are produced by fungi and algae. Algae provide organic matter, fungi provide water and inorganic salts.

10, soybean, peanut and other leguminous plants all have nodules, which are the growth of rhizobia and plants. Rhizobia transform nitrogen in the air into nitrogen-containing inorganic salts (needed by plants), and plants provide organic matter.

1 1. Bacteria can also live with animals, such as herbivores such as cattle and sheep. Some bacteria can decompose cellulose in forage, while animals provide places and food for bacteria.

12, the role of bacteria and fungi in nature: ○ 1 Participate in the material cycle as decomposers; 2. Causes diseases of animals, plants and people; 3 and animals and plants.

13, a few bacteria and fungi are harmful to human body, but most of them are beneficial to human body.

14. In the demonstration experiment of fermentation, the gas in the bubble is carbon dioxide.

15. Yeast can convert glucose into alcohol and carbon dioxide and release a small amount of energy, and its reaction formula is (as shown on the right).

16, carbon dioxide produced by yeast fermentation will form many small holes in the dough, which will make steamed bread or bread swell and soften, and the alcohol in the dough will evaporate during steaming and baking.

17, lactic acid bacteria can convert glucose into lactic acid (acid) under anaerobic conditions, thus turning milk into yogurt and vegetables into pickles.

18. Acetobacter should be used for vinegar and mold should be used for sauce.

19. Food corruption is mainly caused by bacteria and fungi. These bacteria and fungi can obtain organic matter from food, and grow and reproduce in food, leading to food spoilage. An important problem in food preservation is preservation.

20. Method of preserving food: mushroom → dehydration method; Bacon → sun curing and smoking; Preserved fruit → infiltration preservation method; Salted fish → salting method; The above method is based on the principles of dehydration and bacteriostasis. Bagged sausage → vacuum packaging method; Cold storage method; Freezing method; All the above methods are based on the principle of bacteriostasis. Milk → pasteurization; Canned meat → canning method; The above method is based on the principle of high temperature sterilization. Preservatives; Ray method; According to the principle of sterilization.

2 1, the principle of preventing food from spoilage is bacteriostasis and sterilization.

22. Some fungi can produce substances that kill some pathogenic bacteria. These substances are called antibiotics. Penicillium, for example, can produce penicillin and treat bacterial diseases, such as pneumonia, meningitis and gonorrhea.

23. Scientists transfer the gene that synthesizes islet cord into E.coli to produce islet cord (the transgenic E.coli here is a bioreactor).

24, in domestic sewage and industrial wastewater, there are many organic matter can be used as food for bacteria. In an oxygen-free environment, some bacilli and methanogens decompose organic matter in sewage through fermentation to produce methane, which can be used for lighting, heating or power generation, and at the same time, the sewage is purified. Some bacteria decompose organic matter into carbon dioxide and water in the presence of oxygen, so that sewage can be purified. Sewage can be purified by bacteria.

25, 1928, British bacteriologist Fleming found that penicillin can kill bacteria and inhibit bacteria, so he won the Jaubert Prize in medicine or physiology.

26. With the help of modern scientific and technological means, some genes from other organisms are transferred to some bacteria, so that these bacteria can produce drugs.

Unit 6 Biodiversity and Protection

The first chapter classifies organisms according to their characteristics.

1. Biological classification mainly divides organisms into seven different grades (from small to large) according to their similarity, and scientifically describes the morphological structure and other characteristics of each group to clarify the genetic relationship and evolutionary relationship between different groups. Classification is based on the morphological and structural characteristics of organisms. The basic unit of classification is species.

2. Plant classification (see the figure below). (Note: The classification of monocotyledons and dicotyledons is lower than gymnosperms, ferns, bryophytes and algae. Angiosperms, gymnosperms, ferns, bryophytes and algae belong to the same classification level. According to the evolutionary order, from simple to complex, from low to high: algae → bryophytes → ferns → gymnosperms → angiosperms.

3. Classification of animals (see the figure below): from simple to complex, from low to high: protozoa → coelenterates → annelids → molluscs → arthropods → fish → amphibians → reptiles → birds → mammals.

4. In angiosperms, flowers, fruits and seeds are often used as important basis for classification.

5. The seven levels of biological classification, from high to low, are: boundary, phylum, class, order, family, genus and species. Species is the most basic taxonomic unit. The same species has the most characteristics and the closest genetic relationship.

6. Intraspecific * * * features are the most, while intraspecific * * * features are the least.

7. The greater the classification level, the less * * * the same characteristics among organisms, and the farther the genetic relationship; The smaller the classification level, the more similarities between organisms and the closer the genetic relationship. Species at this level have the most common features, while species at this level have the least common features.

8. The greater the classification level, the more species it contains; The smaller the classification level, the less biological species it contains.

9. Classification of horses (from small to large): horse species, Equus, Equidae, Chiroptera, mammals, Chordata, Vertebrate, Animal kingdom.

10. Classification of peaches (from small to large): peach species, plum, Rosaceae, Rosaceae, dicotyledonous plants, angiosperms and plant kingdom.

1 1. Linnaeus, a famous Swedish botanist, put forward the biological nomenclature → binomial method in his book Natural Systems. The scientific name of each species consists of two parts, the first part is the generic name, and the second part is the proper name, which is in Latin and italics respectively.

12, "Natural System" is an epoch-making work in the history of plants, which classifies organisms and reveals the genetic relationship among them, which is of great help to the study of biological evolution.

13. Biodiversity includes biodiversity, gene diversity and ecosystem diversity.

14, China has the largest proportion of gymnosperms in the world, and is the country with the richest gymnosperms, so it is called "the hometown of gymnosperms". Bryophytes, ferns and seed plants rank third in the world, second only to Brazil and Colombia. Among vertebrates, fish, birds and mammals are the largest in the world.

15. Reptiles in China account for the smallest proportion in the world.

16, all kinds of biological characteristics are controlled by genes. The genes of all individuals in each organism constitute a gene pool.

17. Protecting the living environment of organisms and the diversity of ecosystems is the fundamental measure to protect biodiversity.

18, the classification of animals should not only compare the external morphological structure, but also compare the internal structure and physiological function of animals.