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stich3 [128]
2 years ago
8

When did the first life appear?(how many years ago?)​

Biology
2 answers:
Veronika [31]2 years ago
8 0
Alc alc no se pero bendición carnal
Airida [17]2 years ago
4 0
The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old.
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Photosynthesis is an example of...
amid [387]

Answer:

Endothermic reaction

Explanation:

Photosynthesis is an endothermic reaction because sunlight is being absorbed during the reaction and the definition suggests that in a reaction if heat is being absorbed it is termed as an endothermic reaction.

5 0
2 years ago
When a chemical reaction is moving at a slow rat of speed, what can be done to speed up the reaction
Mama L [17]

Answer:

To speed up the rate of reaction, you could increase the temperature or the concentration of the reactants.

Explanation:

Basically, the idea is to speed up the molecules' movement and to cause them to break apart or collide at greater frequency

7 0
3 years ago
What is photosynthesis?
Gwar [14]

Answer:

the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.

Explanation:

8 0
2 years ago
Read 2 more answers
Hat is the law of conservation of energy?
tekilochka [14]

Answer:

Esta Ley fue enunciada en 1785 por el científico francés Antoine Lavoisier.

La ley de la conservación de la energía afirma que la cantidad total de energía en cualquier sistema físico aislado, permanece invariable con el tiempo, aunque dicha energía puede transformarse en otra forma de energía.

8 0
2 years ago
Suppose a population is carrying a condition controlled by two alleles: R (dominant) and r (recessive). Only homozygous individu
White raven [17]

<span><u>The answer is A. 72.25 percent.</u>

The Hardy-Weinberg principle can be used:</span>

<em>p² + 2pq + q² = 1</em> and <em>p + q = 1</em>

where <em>p</em> and <em>q</em> are the frequencies of the alleles, and <em>p²</em>, <em>q²</em> and <em>2pq </em>are the frequencies of the genotypes.

<span>The <em>r</em> allele (<em>q</em>) is found in 15% of the population:
q = 15% = 15/100
Thus, q = </span><span>0.15

To calculate the <em>R</em> allele frequency (<em>p</em>), the formula p + q = 1 is used:
If p + q = 1, then p = 1 - q
p = 1 - 0.15
Thus, </span><span>p = 0.85

Knowing the frequency of the <em>R</em> allele (<em>p</em>), it is easy to determine the frequency of the RR genotype (p²):
p² = 0.85² = 0.7225

Expressed in percentage, p² = 72.25%.</span>

4 0
2 years ago
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