Mature mammalian red blood cells lack nuclei, mitochondria and rough endoplasmic reticulum, they do not contain DNA and consequently, cannot divide. They also cannot synthesise RNA nor synthesise any new proteins, and consequently, have a limited lifespan. Mature red blood cells circulate for about 100–120 days in the body before they are removed by the spleen.
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In active protein translation and folding.
Rough endoplasmic reticulum is called rough because<span> it has many ribosomes on its wall making it look rough. RER is</span><span> involved mainly in protein production, folding, and quality control. Smooth endoplasmic reticulum is specialised in fats and steroids production. </span><span />
There are some things that can prevent decay, one if them is ice, an example of that is a frozen mammoth, ice can prevent the body from decaying, another thing is amber, it can trap an insect and prevent it from decaying, lastly there is tar, a substance that covers thing in a black substance that prevents it from decaying.
Answer: To know if a document is a primary source, check to see when the document is published, if it is an autobiography of a person, a diary, a letter, or the documents happen at the time of the event.
The competition between two organisms can be seen if there is only 1 source of food or habitat space and they're competing against each other for the food or habitat.
There is cooperation between two organisms if they are helping each other with resources or alarming each other if there is danger.
Predation between two organisms happen when one organism hunts the other organism for food.
