Tetanus is caused by an a-b exotoxin called , which is produced by clostridium tetani.

Collagenase is produced by several species of Clostridium, facilitates the spread of gas gangrene. And toxins are produced and secreted by actively growing cells, may be found in foods but are usually inactivated by cooking, the host typically responds by producing antibodies called antitoxin, may be toxic in very tiny amounts, may be produced by gram negative or gram positive bacteria; examples include tetanus toxin, cholera toxin, and staphyloccal enterotoxin.

humans can cause extinction of a species through overharvesting, pollution, habitat destruction, introduction of invasive species (such as new predators and food competitors), overhunting, and other influences. explosive, unsustainable human population growth is an essential cause of the extinction crisis.

explanation:

i didn't have the answer choices , but i tried my best.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]