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sineoko [7]
4 years ago
5

6. When humans first appear on Earth?

Biology
1 answer:
vaieri [72.5K]4 years ago
6 0

Answer:

seven million years ago

Explanation:

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I'm honestly confused right now, please help me.
Fantom [35]

Answer:

The energy of a wave is directly proportional to its frequency, but inversely proportional to its wavelength. In other words, the greater the energy, the larger the frequency and the shorter (smaller) the wavelength.

3 0
3 years ago
Describe one reason why the introduction of brown and black European rats may have led to the extinction of Darwin’s rice rat.
blondinia [14]

Answer:

They were competing for the same type of food.

Explanation:

The introduction of brown and black European rats may have led to the extinction of Darwin’s rice rat due to competition for food and resources. These are the main factors that affects am organisms survival.

The brown and black rat were better adapted for survival and competition of the food and resources available which lead to the death and extinction of Darwin’s rice rat.

7 0
4 years ago
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The side chain of ________ has a pKa in the physiological pH range and is therefore often involved in proton transfer during enz
Free_Kalibri [48]

Answer:

His

Explanation:

The side chain of Histidine has a pKa in the physiological pH range and is therefore often involved in proton transfer during enzymatic catalysis. It is a amino acid which is used for the biosynthesis of protein. Histidine was initially thought to be essential only for infants but now it has  been found to be essential for adults too.If we see the histidine structure contains an α-amino acid, a carboxylic acid group, and an imidazole side chain.

4 0
4 years ago
What happens as electrons pass down the electron transport chain
Leto [7]

Answer:

They slowly lose energy.

Explanation:

High-energy electrons give the chain either NADH or FADH2 to complete it.

Low-energy electrons form water by decreasing the oxygen molecules.

5 0
3 years ago
Read 2 more answers
A car is moving at a constant speed along a straight line. Which statement is true about the forces acting on the car?
steposvetlana [31]
The Answer is D because of the air the car is pushing against
4 0
3 years ago
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