Answer:
endosymbiosis.
Explanation:
By the beginning of the 20th century, researchers thought that plastids and mitochondria could come from bacteria. These would have been ingested by primitive cells and live within them in symbiosis.
Answer:
A. Scientists discovered chromosomes and DNA.
Explanation:
Mendel's ideas were based on patterns of inheritance in plants. Although he identified these patterns, at the time, we did not know what the hereditary material was. This means Mendel couldn't uncover the mechanism of why he was seeing the patterns he was.
When scientists discovered chromosomes and DNA, they were able to see how Mendel's observations made sense in the context of DNA and chromosomes.
The best answer is: introducing exotic species into
<span>
new environments. This can be actually bad, as new species can actually reduce the biodiversity in the environments to which they're introduced</span> , such when cats hunt indigenous birds.
I was a bit thinking about the last option too: making sure local people benefit from conservation efforts.
This is not one of the classical goals of the conservation efforts, but since the previous one is definitely correct, i don't this one is. (it's not that it's not a goal, but it isn't a main focus)
The signs and symptoms of a cluster headache include severe<span> right-sided headache with a runny nose, droopy eyelids, and tearing of the eye on the right side.
</span>The injectable form of sumatriptan<span> (</span>Imitrex<span>), which is commonly used to treat a migraine, is also an effective treatment for acute cluster headache</span>
A chromosome consists of a single, double-stranded DNA molecule. Chromatids are two molecules of double-stranded DNA joined together in the center by a centromere. Chromosomes have a thin ribbon-like structure. Chromatids have a thin and long fibrous structure.
