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daser333 [38]
3 years ago
15

In which era did human history begin?

Biology
1 answer:
Svetllana [295]3 years ago
7 0

Answer:

Prehistoric

Explanation:

The Prehistoric Period—or when there was human life before records documented human activity—roughly dates from 2.5 million years ago to 1,200 B.C. It is generally categorized in three archaeological periods: the Stone Age, Bronze Age and Iron Age.

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Several fish species became extinct millions of years ago. The graphs provided below show the distribution of fossils of these f
cestrela7 [59]
1. Explain why the distribution of fossils in Figure 1 supports the hypothesis that the extinction of these species was the result of a sudden environmental change.
This hypothesis can be supported because all the fossils accumulate almost at the same age of the rock layer. That is, all the fossils died almost at the same time.

2. Describe an environmental change that could have produced this type of fossil distribution.
Good examples of sudden environmental changes are volcanoes. When a rash occurs, the whole environment suddenly changes for different reasons such as ash or lava, and all living things can die immediately or in a few years by the change in the ecosystem.

3. Explain why the distribution of fossils in Figure 2 supports the hypothesis that the extinction of these species was the result of a gradual environmental change.
This is because the fossils accumulate at different ages of the rock layer, that means, the species dying over time. The gradual descent of the fossils is observed.

4. Describe an environmental change that could produce this type of fossil distribution.
For example, if a climate change occurs - the temperature increases or decreases - it can cause the trees or plants to die and all the animals in the ecosystem also die when they have no food. But this process is sequential, so the change can take years, centuries or even millions of years.

I hope this can help you.
4 0
3 years ago
3.PTC is non-toxic and does not occur naturally. Do you think there is a selective pressure that confers an advantage to those w
VikaD [51]

No there is no selective pressure that confers an advantage to those who do taste it.

<h3>What is PTC?</h3>

Despite the fact that PTC isn't found in nature, tasting other bitter substances—many of which are toxins—that do occur naturally has a high correlation with taste sensitivity.

In order to defend themselves from being eaten, plants develop a range of harmful substances. Early humans developed the capacity to distinguish bitter tastes as a safeguard against ingesting dangerous plants. There are roughly 30 genes in humans that produce bitter taste receptors. People may taste a large variety of bitter substances because each receptor can interact with a number of different molecules.

Learn more about Taste with the help of the given link:

brainly.com/question/26220534

#SPJ4

4 0
2 years ago
Help please due tomorrow!!
valentina_108 [34]

Answer:

Y- x+ Y-

Explanation:

when an atom loses electrons the atom the result is a positive ion. when an atom gains an electron, the result is a negative ion

7 0
3 years ago
#8 - The Genetic Code<br> 18. How many amino acids are involved in the production of proteins?
Phoenix [80]

Answer: 20 amino acids

Explanation:

The Genetic code permits the triplet nature of codons whereby three nucleotides from Adenine, Uracil, Guanine and Cytosine on the messenger RNA (mRNA) join to form 64 codons.

Since more than one codon can specify for an amino acid, the 64 codons then specify for 20 amino acids, that then form the sequence of various proteins

7 0
3 years ago
Read 2 more answers
Scientists have described and named a total of_______species.
Whitepunk [10]

Answer: 1.9 million species

Explanation: I looked it up

3 0
3 years ago
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