Please help someone with knowledge of biology, I don t know much about biology, please help

Yes, without restrictions.

Mating refers to the exchange of germ cells of living organisms, leading to fertilization and reproduction, that is, sexual reproduction, so the grafting mentioned above is incorrect. The way to distinguish between different species is to see if there is reproductive isolation, that is, mating does not produce fertile offspring, but can produce fertile offspring, which is naturally the same species.

In different regions, geographical isolation is generally formed, but as long as it does not evolve into reproductive isolation, it is still the same species, but it will be called a subspecific order: subspecies, variants, ecotypes, and essentially the same species.

For example, plants are not descendants of grafting techniques.

Animals are all one species.

Species vary from region to region.

Ants, for example, are different from place to place.

Animals are not a species, they must be stable in genetics!

It should be said that the criterion for determining whether a species is a species is reproductive isolation, and the existence of reproductive isolation means that sexual reproduction is the existence of interbreeding incompatibility or the infertility of its offspring. Strictly speaking, mating should be sexually reproductive, and if the offspring is not capable of reproduction, it can be determined that this one has reproductive isolation, and the two belong to different species.

There is no restriction on whether reproductive isolation occurs in areas that are not in the same area. For example, the Siberian tiger and the South China tiger are different subspecies of the same species, and there is no so-called reproductive isolation between the two, but one is in the south and the other is in the north. However, the seedless watermelon we often eat is a real counterexample.

The common triploid seedless watermelon is obtained by crossing diploid ordinary watermelon with tetraploid watermelon obtained after colchicine treatment under artificial conditions. Usually, it is the former that provides the pollen and the latter that provide the egg cells, and finally the triploid seeds are produced on the latter plant, and then they are planted, and the triploid seedless watermelon can be obtained the next year! However, because triploidy causes union disorder, it is unable to produce fertile gametes and thus cannot reproduce normally.

Therefore, diploid watermelon and tetraploid watermelon are two different species, but they are often planted in interlaces for convenience, which shows that the occurrence of reproductive isolation does not have to be very far away.

A species is an animal or group of plants whose members are so similar in morphology that they can be considered to be identical organisms with little variation, and whose members can mate normally and produce fertile offspring. Species are reproductive units, and individuals of the same species can mate and reproduce, while heterogeneous individuals are interbreeding and sterile, forming reproductive isolation.

Subspecies generally refers to geographic subspecies, which are the geographical differentiation of populations with certain distinguishing characteristics and distribution ranges. Subspecies classification reflects species differentiation and highlights the spatial concept of species. Geographic subspecies are all geo-subspecies, and there are often intermediate types in the junction area.

So in areas not in the same area is a subspecific taxonomy, may be a different subspecies, but still a species.

After fertilization, an organism is considered a species if it can produce fertile offspring.

If it does not produce offspring, or if the offspring is infertile (e.g. horse + donkey = mule), it does not belong to a species.

1. Simply list the methods provided in the biology textbooks for primary and secondary schools.

Food nutrients are generally divided into six categories:

Sugars, mainly starches, can be tested with iodine;

Fat, divided into vegetable oil and animal fat, can be tested with Sudan dyes;

protein, which can be tested with biuret reagent;

water, which can be tested by the baking method;

Inorganic salts, which can be tested by ash method;

Vitamins can be tested by chemical methods (different vitamin testing methods are different) 2. Inferior milk or milk powder is generally doped with starch powder, so you can test it with iodine wine, mainly to see if the solution of this milk or milk powder will turn blue.

In fact, there are two pathways: systemic circulation and pulmonary circulation.

Systemic circulation: blood enters the aorta from the left ventricle, then flows through all levels of arteries, capillary networks, and veins throughout the body, and finally collects into the superior and inferior vena cava, and flows back to the right atrium. This circulatory pathway is called the systemic circulation.

Pulmonary circulation: The blood flowing back to the right atrium is pressed into the pulmonary artery through the right ventricle, flows through the capillary network of the lungs, and then flows back to the left atrium from the pulmonary vein, and this circulatory pathway is called the pulmonary circulation.

Systemic circulation is the blood from the left side of the heart to the right side, and pulmonary circulation is the blood from the right side of the heart back to the left, thus forming a complete blood circulation pathway.

For example, if it's the heart, your uncle can write it according to the cycle.

1) Waste battery leaching has an impact on the life activities of goldfish.

2) The same species and almost equal in size and vitality.

3) The leaching solution of waste batteries has an effect on the life activities of goldfish, and the greater the concentration, the greater the impact.

4) It is necessary to add a fish tank, put three goldfish of the same size and vitality in it, only add water to the tank and feed the same kind of feed regularly.

28. (1) afferent nerves; Synapse; Effectors.

2）c；presynaptic membrane, synaptic cleft, postsynaptic membrane; Neurotransmitters.

3) Positive on the outside and negative on the inside; Positive inside and negative outside; Potential difference.

29. (1) globulin; b lymph; Plasma cells.

2）b；Rapid response, production of a large number of antibodies in a short period of time; d。

Ganglia Gray matter Receptors D Presynaptic membrane Synaptic cleft Postsynaptic membrane Right arrow Neurotransmitter Positive on the outside and negative on the inside.

Positive and negative potential difference between inside and outside.

1) The amount of protein B slurry C B is large and rapidly d

1) Centrosomes of mitochondria and the external environment

2) Base species and carbon-free sugars E1 and E2 are deoxynucleotides and ribonucleotides, respectively.

3) mRNA translation.