Teeth patterns in animals and thorns in plants are examples of characteristics that a taxonomist might observe for keying.

Answer:

Most ocean pollution begins on land.

Much of this runoff flows to the sea, carrying with it agricultural fertilizers and pesticides. Eighty percent of pollution to the marine environment comes from the land. One of the biggest sources is called nonpoint source pollution, which occurs as a result of runoff.

Answer:

Plastic pollution: The ocean is estimated to contain millions of tons of plastic debris, much of which comes from land-based sources.Chemical pollution: The ocean is also contaminated with a wide range of chemicals, including pesticides, herbicides, and industrial and household chemicals.Nutrient pollution: Excess nutrients, such as nitrogen and phosphorus, can enter the ocean from agricultural and urban runoff and contribute to the growth of harmful algal blooms.Oil pollution: Oil spills and other oil discharges into the water can have a negative effect on the animals and marine ecosystems there.

Explanation:

https://www.quora.com/What-percent-of-the-ocean-is-polluted

Answer:

The answer to the question: What effect will the decreased iron availability have on the production of diphteria toxin, would be, A: The lack of co-repressor binding to DtxR will lead to a loss of repression and an increase in the production of toxin.

Explanation:

Diphteria is a very serious disease that is caused by the gram-negative bacteria Corynebacterium Diphtheriae, which attacks the upper respiratory tract, especially the throat, and causes a thick lining to form, complicating the normal respiratory function. In order to accomplish such a feat, this bacteria produces a toxin that attacks human cells. But the toxin will not be produced if there is a high availability of iron in the area where the bacteria intends to infect, because if that is the case, then iron will work as a co-repressor with DtxR to prevent the expression of the bacterial gene that codes for the toxin. A co-repressor means that iron will work as a coadjuvant for DtxR and will not allow the genes of the bacteria to produce the toxin. In the case of this question, the answer is A because we have a lack of iron availability, which means that DtxR will not be enough to stop the toxin from being produced.