How do diffusion helps animals exchange gases.

You have 46 chromosomes in each of your somatic cells. If you cut your arm, how many chromosomes would be in each newly formed s

rosijanka [135]

You would have .3 of a chromosome for each new cell

7 0

3 years ago

PLEASE HELP ASAP

fgiga [73]

Answer:

The main purpose of the circulatory system is to transport blood, oxygen, nutrients and hormones to and from different cells and tissues throughout the body.

Explanation:

This system works hand-in-hand with the respiratory system to facilitate the exchange of oxygen and carbon dioxide within the blood per the alveoli in the lungs.

7 0

3 years ago

6. A scientist measures the circumference of acorns in a population of oak trees

melisa1 [442]

Answer:

6. 2 cm

8. Greater than 2 cm and less than 2 cm

Explanation:

Complete Question

6. A scientist measures the circumference of acorns in a population of oak trees and discovers that the most common circumference is 2 cm. What would you expect the most common circumference(s) to be after 10 generations of stabilizing selection?

-2 cm

-Greater than 2 cm or less than 2 cm

-Greater than 2 cm and less than 2 cm

-Can't tell from the information given

8. Refer to question 6, but this time answer what you would expect after 10

generations of directional selection.

-2 cm

-Greater than 2 cm or less than 2 cm

-Greater than 2 cm and less than 2 cm

-Can't tell from the information given

Solution -

6. In an stabilizing selection, the average trait of a given population is favored over extreme values. Hence, it can be said that one specific trait is over presented in a given population. For example – uniform human birth weight, number of eggs a bird lay etc.

Here in this case if most common circumference is 2 cm , then the tree population will try to have this trait as a stabilizing trait.

Thus, option A is correct

8. In a directional selection, the genetic variation decreases as per the environmental change. And hence the average trait will not be selected. Instead traits either higher or lower the average values will be preferred.

Thus, option C is correct

3 0

3 years ago

1. Describe DDT and summarize the history of the use and banning of DDT, including actions taken by the U.S. government. State t

igomit [66]

DDT stands for dichloro-diphenyl-trichloroethane. The first kind of synthetic/artificial insecticides came into use in the 1940s. The earlier usage of DDT include: a) Killing of malarial vectors, b) Combatting Typhus and other insect borne human diseases, c) As a pest control in crops d) as a pest control in garden, live stock production and even at homes.

The negative impact of DDT could be felt for the first time when the pests that were earlier killed by use of DDT have now become pesticides resistant. In the 1950s in USA, the regulatory measures were adopted to reduce the usage of DDTs as its effects as a pesticides were no more long significant and also it was creating detrimental physical and psychological impacts on the human and environment.

It was in 1972 that the U.S. Environmental Protection Agency cancelled the order for banning the usage of DDT based on the adverse impact it produced on the environment, human and other life forms. Since then continuous studies are being conducted to analyse the impact of DDTs. In some later years it was established that DDT is the cause of producing tumors in liver.

Some of the common negative impacts produced by DDT as per the U.S. Department of Agriculture :

a) The non destructive nature – DDT can not be destroyed and thus it remains persistent in the atmosphere

b) It attacks the tissues of living organisms especially the animals and humans ( fatty tissue)

c) It can penetrate the atmosphere to deeper extent.

Now as per the current stuation, The use of DDT is controlled and other alternatives of pest control organisms is being deduced. As per the treaty of Stockholm Convention on POPs (Persistent organic pollutants) , usage of DDT for malarial control is justified but it puts a restrictive use of DDT as pesticides in other areas.

4 0

3 years ago

Read 2 more answers

Which human activities would most likely increase turbidity? Check all that apply.

olasank [31]

Answer:

C

Explanation:

7 0

3 years ago

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