Examples of termites and flagellates: Termites provide food and habitat for flagellates, and flagellates break down wood chip fibers for both parties to use

Examples of crucian carp and large fish: crucian carp is adsorbed on the surface of large fish, which is not beneficial to large fish and increases the chances of crucian carp foraging

Examples of roundworms and human body: roundworms use food in the human digestive tract as a source of nutrition, resulting in malnutrition and developmental disorders in the human body.

Nematodes and tapeworms that are parasitic in the intestine: evolved into linear or banded shape to adapt to the intestinal cavity

Extracorporeal parasitic fleas: flat on both sides, wingless, and swing-like for easy movement

Organ changes: such as digestive tract flukes and tapeworms produce attachment organs, tapeworms degenerate digestive organs, protozoa motor organs are lacking, many parasites have developed reproductive systems and even hermaphrodites

Intestinal parasites change from aerobic metabolism to glycolysis to obtain energy

Tapeworm mature section with male and female reproductive system

Female roundworms lay about 200,000 eggs per day

Female Ban's Wuce nematode produces millions of larvae

Fludes have generational alternation of sexual reproduction and asexual reproduction

Toxoplasma gondii secretion penetration enhances cell invasion ability

The tissue-lytic amoeba synthesized proteolytic enzyme invades the host intestinal wall tissue, while the co-occurring colon cannot

Trypanosoma Africa replaces glycoproteins on the surface of insects to produce neoantigens to avoid immune attacks

Childworm Mann's lung stage combines host antigen to avoid epidemic attack

Environmental pressure causes the parasite gene to mutate or recombinate, resulting in phenotypic changes. For example, the genome difference between Taiwan, Taiwan, and other geographical strains, leads to the inability to cause disease to the human body.

Plasmodium development stages must be carried out in humans and mosquitoes

Hookworm larvae can grow on its own and must invade the human body's parasites when it develops to a certain stage.

The feces are usually self-generated in the soil and can also invade the human body's parasites.

For example, the perverted intestinal nematodes parasitizes in the intestine, the larvae parasitizes in skeletal muscle tissue, and the toxoplasma gondola in the cells

Mainly refer to mosquitoes, levitra, lice, flea, tick and other arthropods, mostly temporary parasites

The host's immune function is normal and it causes disease when it is hypoimmune, such as Toxoplasma gondii and cryptosporidium

The host that is parasitic in adults or sexual reproductive stages, such as Schistosoma worm parasitizes in the human body, and the human is the final host

The hosts parasitic larvae or asexual reproductive stage are divided into first and second intermediate hosts. For example, the first intermediate host of Cystosacia is freshwater snail, and the second intermediate host is freshwater fish

Certain parasites can be parasitic in humans and in vertebrates. The latter can transmit parasites to humans under certain conditions. For example, Cystosomiae can parasitize in humans and cats, and cats are hosts for insect preservation.

Parasite larvae invade into non-suitable hosts and cannot develop into adults, but they can survive and maintain their larval state for a long time. Only by invading suitable hosts can they develop into adults. For example, if the child worm invades the wild boars, they cannot develop into adults. Wild boars are reincarnated hosts.

The energy sources of parasites are mainly through glycolysis. The parasitic environment and oxygen content are different. For example, ascaris eggs and larvae undergo aerobic respiration, while adults undergo rosaic acid respiratory system in the small intestine.

Many worms and protozoa such as Plasmodium, Giardia lancea, tissue-lysed amoeba, etc. mainly obtain energy through glycolysis.

Parasite growth and reproduction require high-speed anabolic metabolism, but the nutrition comes from the host and the anabolic species are limited. For example, parasitic worms cannot synthesize cholesterol and unsaturated fatty acids, and most protozoa cannot synthesize cholesterol.

Nucleotide metabolism: Parasitic protozoa and helminths lack the initial purine synthesis pathway, relying on remedial pathways, pyrimidine synthesis is through de novo synthesis and remedial pathways, such as trypanosoma, Plasmodium, Toxoplasma gonzo

Amino acid metabolism: Trypanosoma Rhodesia can synthesize a variety of amino acids from phosphoenolpyruvate. The catabolism of protozoa varies from species to species. The worms actively absorb amino acids, and its catabolism is not completely clear.