Spongy bone contains needle like threads of bone known as

Why is the horseshoe crab an example of a living fossil?

Readme [11.4K]

Answer:

A. There are fossils of extinct ancestors of horseshoe crabs and the species is still alive today.

Explanation:

C and D have more to do with how it can be a fossil. It is a living fossil because its ancestors have been found in fossils, yet it continues to live today.

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2 years ago

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2) A population of animals is permanently split by a natural barrier into two separate populations in different environments. Wh

kaheart [24]

Answer:

C) The two populations will evolve into separate species.

Explanation:

In the given question, the population of animals has been split into two different populations due to a natural barrier present between them.

When we will observe these species after a very long time, the species will not be able to reproduce with each other and will be reproductively isolated. This reproductive isolation will lead to the formation of new species but belonging to the same genus.

Thus, Option-C is correct.

4 0

2 years ago

Consider a series of metabolic events during fasting. Within a few days after a fast begins, nitrogen excretion accelerates to a

timurjin [86]

Answer:

A series of events occur, in prolonged fasting; the body undergoes changes and adaptations of its metabolism to continue to meet energy needs and maintain vital functions, despite not receiving food

These changes are divided into three phases according to the elapsed days of fasting and according to the metabolic processes involved.

First phase: main consumption of reserve carbohydrates.

Second phase: main consumption of fats.

Third phase: serious consumption of proteins.

Explanation:

If the fast is prolonged in time, the metabolic processes change in their qualitative and quantitative characteristics, so that the energy products consumed (glucose, free fatty acids and ketone bodies) are modified, their oxidation decreases globally and after the initial depletion of hepatic and muscular glycogen and protein catabolism, the main source of glucose is the liver through gluconeogenesis. The substrates initially come from protein catabolism and lipolysis, but later protein destruction slows down, maximizing lipolysis.

Between the first phase and the second phase of the fast some muscle proteins are lost but not excessively, even with fasts of two or three weeks.

After about 2 weeks of fasting, up to two-thirds of the energy the brain needs is obtained from ketone bodies. These ketone bodies are the breakdown products of fats and are responsible for the typical ketone breath reminiscent of the smell of acid apples; urine also smells like ketone.

In this phase, damage begins to occur in some important organs such as the liver and kidneys. Starting the first week of fasting, acidosis affects the heart's function of the circulation and the brain.

In the third phase of the prolonged fast it happens from 3 weeks, that is, about twenty days without food, although it varies according to the constitution of each person. A peak of muscle protein consumption occurs and a great loss of weight begins to be perceived with great weakness. Edema occurs and albumin concentration in the blood is altered, as a sign of the self-digestion of muscle proteins.

From approximately 30 days of fasting, the state of malnutrition severely affects all body systems. After forty or fifty days the deterioration is noticeable due to physical wear, the person loses his mobility and suffers from unconsciousness. Finally, starvation death can occur from cardiorespiratory arrest or from lack of blood supply to the brain.

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3 years ago

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Helppppppp plz thx........

8090 [49]

Answer:

1) aa- affected

2) Aa- unaffected carrier

3) aa- affected

4) aa- affected

5) Aa - unaffected carrier

6) Aa- unaffected carrier

7) aa- affected

8) aa- affected

9) Aa- unaffected carrier

10) aa- affected

11) Aa- unaffected carrier.

This trait is <em>recessive</em>.

The F1 generation has a 50/50 chance of having unaffected offspring.

Explanation:

1) Given

2) Some of the offspring have the trait, and they're not affected, so they have to be a carrier

3) The box is shaded in so they have to have the trait, which means they have to have the same gene pattern as the other affected person (#1)

4) They are also shaded in, so they have to have the trait

5) Since the parents either have the trait or are carriers, if they're not affected they have to be a carrier

6) Same reasoning as #5

7) This is shaded in, the box has to have the trait

8) Shaded in = has the trait/affected

9) Since the parents either have the trait or are carriers, if they're not affected they have to be a carrier

10) Shaded in = has the trait/affected

11) Since the parents either have the trait or are carriers, if they're not affected they have to be a carrier

Since the trait is displayed when the people have two lowercase letters (aa), and people can be unaffected and carriers, (Aa), this trait has to be recessive.

If you make a Punnett Square, you will see that half of the offspring can result in an Aa, while the other half can result in an aa, meaning there's a 50/50 chance of the offspring of the F1 (first) generation will have the trait.

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2 years ago

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Human made gases that contain a combination of chlorine, fluorine, and carbon. The combination of these gases put a hole in Eart

dalvyx [7]

The answer is.. C

HOPE THis helps!!

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2 years ago

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