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Annette [7]
2 years ago
7

Each stage of the sleep cycle lasts about how long? an hour 30 minutes 15 minutes 90 minutes

Biology
1 answer:
zalisa [80]2 years ago
8 0
Hey You!

There are 5 stages of the sleep cycle, and each stage lasts about 5-15 minutes long (usually around 10-15, though).

And that's youd answer! ^
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Sparrows with average-sized wings survive severe storms better than those with longer or shorter wings, illustrating
Artyom0805 [142]

Answer:

The correct answer is option B) "stabilizing selection".

Explanation:

Stabilizing selection is a type of natural selection at which mean traits are favored by nature instead of extreme values. In this case at which sparrows with average-sized wings survive severe storms better than those with longer or shorter wings illustrates stabilizing selection. It its believed that this type of selection is the most commonly found in nature, since most traits have no extreme values in most of the species.

6 0
3 years ago
Airplanes reach cruising altitudes at the lower part of the Earth's stratosphere. This portion of the atmosphere is made up most
Lerok [7]

Answer:

The stratosphere is a layer of Earth's atmosphere. ... The troposphere, the lowest layer, is right below the stratosphere. ... Because of this, jet aircraft and weather balloons reach their maximum operational altitudes within the stratosphere. ... from the bottom of the stratosphere up to altitudes of 40 or 50 km (25 to 31 miles).

Explanation:

6 0
3 years ago
What are the characteristics that classify an object as being living called?
Arte-miy333 [17]

Three of the major characteristics used to classify organisms are cell structure, mode of nutrition and cellularity. These characteristics help scientists determine how organisms are similar to each other as well as how they are different from each other.

4 0
2 years ago
What tissue makes up most of the wood of a tree? A. primary xylem B. secondary xylem C. secondary phloem D. vascular cambium
Over [174]

<u>B. Secondary xylem</u> tissue makes up most of the wood of a tree.

<h3><u>What exactly is secondary xylem?</u></h3>

Secondary xylem is a sort of xylem produced by secondary growth. During initial growth, in contrast, the primary xylem develops. As a result, the secondary xylem is linked to the primary xylem by lateral growth as opposed to the vertical extension.

The kind of cambium that gives rise to each difference is another point of differentiation. The vascular cambium produces the secondary xylem, while the procambium produces the primary xylem.

Unlike trees and shrubs, non-woody plants lack secondary xylem. It gives such plants mechanical support by depositing lignin into their cell walls, thickening them. Compared to the major xylem, the secondary xylem is made up of tracheids and veins that are shorter and wider. In comparison to the primary xylem, it is also richer in xylem fibers.

Possible growth rings in the secondary xylem (or annual rings). Sapwood and heartwood are two differentiators of the secondary xylem in big woody plants.

Learn more about secondary xylem with the help of the given link:

brainly.com/question/703995

#SPJ4

4 0
1 year ago
The endosperm of a Conifer seed is:
riadik2000 [5.3K]

Answer:

A. Haploid (n)

Explanation:

Conifers do not exhibit double fertilization that forms triploid (3n) endosperm in flowering plants.

Endosperm in conifers develops from the haploid cell of female gametophyte before fertilization. Since the endosperm is formed by the mitotic divisions in the haploid cell (n) of female gametophyte, it is haploid (n) in nature.  

5 0
3 years ago
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