Answer:
Blood-brain barrier.
Explanation:
Blood brain barrier may be defined as the barrier between the blood capillaries and the component of the brain tissue. This blood brain barrier provide protection against the pathogens present in the blood.
The blood-brain barrier uses tight junctions that prevent the entry of microbes in the underlying tissue. The tight junctions allows only the entry of some selected particles and prevent the entry of other particles.
Thus, the correct option is (3).
Because the species of finches on the Galápagos island have various appearances but still mate with other finches and produce fertile offspring making it is difficult for scientists to distinguish between two groups of individuals as separate species.
<h3>What is the island of Galápagos?</h3>
The Pacific Ocean island of Galápagos is located to the west of Ecuador. It is a volcanic island known for its diverse and endemic types of living things.
<h3>Why is it difficult to find new species in Finches?</h3>
Charles Darwin spent several years studying the many species of finches on the Galápagos island. He saw a great deal of variation in these finches, which supports the hypothesis of natural selection.
However. it is challenging for scientists to discern between two separate species because the species of finches on the Galápagos island have a variety of features that are different but still mate with other finches and produce fertile offspring.
To learn more about evolution visit:
brainly.com/question/19431143
#SJ4
Answer:
Lakes and rivers provide Canadians not only with drinking water, food, transportation networks and recreational opportunities, but also with hydroelectricity. In fact, Canada is one of few countries around the world to rely on hydropower for more than half of its electricity needs.
Explanation:
The nine activities that scientists engage in as a part of scientific inquiry are the following:
1. Observe
2. Define the problem
3. Form a study question
4. Research the problem
5. State the expectations (hypothesis)
6. Experiment and gather data
7. Analyze the results
8. Reflect on the findings
9. Communicate with the wider community
Samoset and Squanto both speak using the English language.
