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pochemuha
3 years ago
5

Sharks have existed on Earth for centuries, even thousands of years with very little change to their structure. Why do you think

that is? Defend your answer.
Biology
1 answer:
iris [78.8K]3 years ago
6 0

Answer:

Sharks, in their basal form have been on Earth for hundreds of millions of years.  They were the first to develop a stream-like, torpedo shaped body and created a niche for themselves. Their aerodynamic body shape has evolved to allow for efficient and dynamic movement in water. Having a cartilage instead of bones allowed them to grow large and still be relatively light and buoyant . After they've evolved flexible, protruding jaws, there wasn't much to change. They were able to adapt and exploit all the water habitats as the world was changing.

Explanation:

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If you were a scientist studying traits which are selected by humans instead of the environment, you would be studying the follo
Dvinal [7]

The correct answer is: Artificial selection (selective breeding).

Artificial Selection is a form of selection, totally influenced by human, in which traits that should be passed onto offspring are chosen by human. Selective breeding was used long before the genetics was discoverd. Farmers used individuals with beneficial traits, larger in size, with bigger fruit etc.

Hunting is also one type of selective breeding, since the hunters choose the animal and remove it from the population (gene pool), leaving the “weaker” to pass on to the next generation.


3 0
3 years ago
In 1985 a biologist counted 750 pine trees in a 250 hectare forest. Using similar counting techniques, the biologist counted 1,2
Alisiya [41]

Answer:

Suppose that we have a given function f(x)

The average rate of change of the function between two values x₁ and x₂ is given by:

r = \frac{f(x_2) - f(x_1)}{x_2 - x_1}

a) We want to find the average (rate) of change on the size of population from 1985 to 1995.

We have that:

f(1985) = 750

f(1995) = 1500

Then we have:

r = \frac{1500 - 750}{1995 - 1985}  = 750/10 = 75

This means that the population of trees increases, in average, at a rate of 75 trees per year.

b) What is the density of trees each year that they were counted?

This will be equal to the quotient between the number of trees and the area.

1985: number of trees = 750 pines

         area = 250 ha

Then the density is:

D(1985) = (750 pines)/(250 ha) = 3 pines/ha

So 1985, there were 3 pines per hectare.

1990: number of trees = 1250 pines

         area = 250 ha

Then the density is:

D(1990) = (1250 pines)/(250 ha) = 5 pines/ha

1995: number of trees = 1500 pines

         area = 250 ha

The density is:

D(1995) = (1500 pines)/(250 ha) = 6 pines/ha

3) now we want to get the average change between 1985 and 1995 in the density, this will be:

r = \frac{D(1995) - D(1885)}{1995 - 1985}  = \frac{6 pines/ha - 3pines/ha}{10}  = 0.3 pines/ha

So, on average, each year the number of pines per hectare increases by 0.3

7 0
3 years ago
What are some effects of prostaglandins in the body?
Amanda [17]

A class of lipids called prostaglandins is typically produced at the sites of injury or infection and is used to treat both disease and injury. They regulate functions like blood flow, blood clot formation, inflammation, as well as labor induction.

Arachidonic acid, from whom prostaglandins are generated, is what causes inflammation:

  1. In synthetic form, prostaglandins are used to induce labor and give birth.
  2. They trigger uterine contractions and have a ring structure with at least two or three and perhaps more carbons.

Effects of prostaglandins in the body are

  • The hormone that circulates and regulates the kidney's reabsorption of sodium. Prostaglandins, which seem to be present in high concentrations, directly affect nerve terminals to induce pain.
  • The production of the inflammatory response is significantly influenced by prostaglandins. Their production is markedly increased in inflamed tissue, therefore they help to produce the essential symptoms of acute inflammation.
  • NSAIDs (which inhibit cyclooxygenase) as well as COX-2 selective inhibitors, sometimes known as coxibs, were examples of prostaglandin antagonists. Cyclopentenone prostaglandins as well as corticosteroids, which block the formation of phospholipase A2, might help to reduce inflammation.

To know more about  Prostaglandins here

brainly.com/question/27180318

#SPJ4

4 0
1 year ago
WILL GIVE BRAINLIEST!!!
Rama09 [41]

Answer:

i would like to choose sublimation process to explain about water cycle.As mentioned, sublimation is the process in which snow melts and water get vaporized. Ice melts and turns into water which flows to the seas and oceans.When the temperature increases during the day time, water gets vaporized.Water vapour begin to move upward.As we know, temperature decreases with the increase in height.Due to which water vapour rises,cools and then changes into tiny water molecules.Those water molecules forms cloud.Then the clouds get heavier and begin to collide with each other.As a result rain fall occurs.

Evapotranspiration has also the same process but the difference is that it involves vaporization of water from some biological factor like plants and physical factor like from soil .

i think its my first longest answer which i answered here.Thank you for the amaizing question. Its simple but most important topic

4 0
3 years ago
This type of bonding occurs when one atom has enough strength of attraction to remove the electron from another atom
MakcuM [25]

Answer: Ionic bond

Explanation: Ionic bond is a type of chemical bond which occurs by removing one or more electron from one atom and it is attached to another atom which gives a negative and positive ions that attract each other. For example Sodium chloride Nacl2.

6 0
3 years ago
Read 2 more answers
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