Which element is not found in abundance in the atmosphere?

Which systems work together to cool the body?

REY [17]

<span>Human skin is one of the more important cooling systems. Unlike many other mammals, humans have sweat glands. These cool the surface of the skin by evaporating water. Body heat is carried to the surface of the skin by the circulatory system. Humans also have finer hair than other animals. We are actually as hairy as chimpanzees, but our hair is so fine it makes us appear to have none. This lack of dense hair allows the skin to evaporate sweat more efficiently. Another human cooling mechanism is our posture. Walking upright means only a small portion of the body is exposed to direct sun during the hottest part of the day. Our ancestors were thought to scavenge during this period because preditors had to escape the sun. Walking on 4 legs meant the entire surface of the back was exposed to the sun.A uniquely human adaptation to heat is the scalp. Blood vessels run directly from the surface of the brain through pores in the skull and out across the head and face. This serves to cool the brain. Humans have enromous brains which generate quite a lot of heat. This system of veins serves like a kind of radiator, keeping the brain from overheating. It also explains why head injuries tend to bleed so profusel</span>

3 0

3 years ago

Are lysosomes in plant and animal cells

xz_007 [3.2K]

Answer:

Yes.

Explanation:

4 0

4 years ago

Read 2 more answers

Prokaryotic organisms have recently been divided into two domains, bacteria and archaea. this division is based on characteristi

Tema [17]

Your answer is E. a, b, and c ♥

8 0

3 years ago

Comparing amino acid sequences in proteins has been used to determine the relatedness of organisms. Below is a graphic that show

Tju [1.3M]

Answer:

A) Species A and E are more closely related than either species are related to species D.

B) Between A and B = 99.1%

Between species A and C =97.5%

Between species B and C = 97.3%

Similarity in amino acids sequence reflects similarity in DNA sequence

C) Species A and E are most closely related

D) Species A and E have the most similarity in amino acid sequence, and hence DNA sequence.

Explanation:

A) The amino acid sequences of the protein, keratin, in species A and D has a difference of about 19 whereas species A and E have a difference of only 1. Therefore, it means that keratin in species A and D will have differences in structure whereas between species A and E, they would have almost the same structure.

Also, species D and E have a difference of 20 in their amino acids sequence, therefore, the structure of keratin in both species will have differences in structure.

B) Similarity between A and B:

450 - 4 = 446

In percentage: 446/450 × 100% = 99.1%

Similarity between A and C:

450 - 11 = 439

In percentage: 439/450 × 100% = 97.5%

Similarity between B and C:

450 -12 = 438

In percentage: 438/450 × 100% = 97.3%

The sequence of DNA of species determines their amino acid sequences because information in DNA is transcribed to RNA which are then used to make proteins. Therefore, if a species are very closely related, they are expected to have very similar genetic sequences and thus proteins too. This is reflected in similarity between amino acid sequences in their proteins.

C). Species A and E are most closely related.

D) Species A and E have only a single difference in their amino acids sequence for Keratin. This translates to about 99.7% similarity which is the highest among all the species compared. Therefore, species A and E are most closely related.

7 0

3 years ago

What two systems are responsible for maintaining homeostasis during exercise

Evgesh-ka [11]

Respiratory- You breath faster to help supply the muscles with more oxygen.
Integumentary (skin) - Sweat helps cool down the body.

5 0

4 years ago