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Ipatiy [6.2K]
3 years ago
15

The endosymbiosis theory states the origin of eukaryotic cells began when

Biology
1 answer:
Art [367]3 years ago
5 0

It is thought that life arose on earth around four billion years ago. The endosymbiotic theory states that some of the organelles in today's eukaryotic cells were once prokaryotic microbes.

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What happens a river ages
s2008m [1.1K]
D. the floodplain shrinks
5 0
3 years ago
Read 2 more answers
1. Why does the moon go through Phases?
liq [111]

Explanation:

1.The Moon has phases because it orbits Earth, which causes the portion we see illuminated to change. The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 days. The Moon spends the extra 2.2 days "catching up" because Earth travels about 45 million miles around the Sun during the time the Moon completes one orbit around Earth.

2.

An eclipse is the result of the total or partial masking of a celestial body by another along an observer's line of sight. Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view.Lunar and solar eclipses occur with about equal frequency. Lunar eclipses are more widely visible because Earth casts a much larger shadow on the Moon during a lunar eclipse than the Moon casts on Earth during a solar eclipse. As a result, you are more likely to see a lunar eclipse than a solar eclipse.

3.Why Do We have Seasons?

As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's axis points towards the sun, it is summer for that hemisphere. When the earth's axis points away, winter can be expected. Since the tilt of the axis is 23 1/2 degrees, the North Pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can.

Why Do the Seasons Change on Earth?

Two things cause the seasons to change. First, the Earth moves around the Sun. Second, the Earth has a tilted axis of rotation.

The Earth spins around an axis. This imaginary line extends from the South Pole to the North Pole. But the Earth’s axis is not vertical. It’s actually tilted at an angle of 23.5°. The planet is always tilted in the same direction as it orbits the Sun.

4 0
3 years ago
If you have a problem remembering things that happened a year ago, doctors might check for damage to the area of the brain calle
Alex777 [14]
Answer - Hypothalamus

Reasoning - In that area which is the hypothalamus it has concentrated nerve areas where its function can be (autonomic) such as temp, homeostatic, and basic remembrance. Just like what your reading now your automatically recalling what your reading.


8 0
4 years ago
The days are longer or shorter because the earth’s axis in blank
allochka39001 [22]

Answer: Orbit

Explanation: The Earth’s axis being in orbit means that the Earth is in different positions around the sun at different points in time, causing day and night.

7 0
3 years ago
Which of the following is an advantage of internal fertilization
slavikrds [6]

Answer and Explanation:

Internal fertilization is characterized by sperm fertilizing the egg within the female. More protection against outside environments and predators, and therefore a higher chance of surviving until birth .  The young develop within the female, receiving nourishment from the mother’s blood through a placenta. Less chance of desiccation of gametes. Internal fertilization also enhances the fertilization of eggs by a specific male since the females are more selective of their mates thus increasing chances of gametes meeting . Even though fewer offspring are produced through this method, their survival rate is higher.

5 0
3 years ago
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