Why might a company decide against using hydroelectric Energy as an alternative energy source

Individuals who are affected by Sickle Cell Anemia have a mutation which leads to the production of valine instead of glutamic a

r-ruslan [8.4K]

Answer:missense

Explanation:I just did this question and I got it right, so that’s how I know it’s right lol.

4 0

3 years ago

If you made a Punnett square showing Gregor Mendel’s cross between true-breeding tall plants and true-breeding short plants, the

nekit [7.7K]

Answer:

C

Explanation:

Assume that allele A is the dominant allele that produces the dominant phenotype (tall) in plants that have at least one allele A, and allele a is the recessive allele that produces the recessive phenotype (short) in plants that have two alleles a.

In the parental generation, a true-breeding tall plant has the AA genotype (phenotype: tall), and a true-breeding short plant has the aa genotype (phenotype: short).

We have the Gregor Mendel's cross as in the image attached here.

All of the F1 generation (offspring plants) have the Aa heterozygous genotype, and therefore, they are all tall.

The answer is c (the offspring plants have a genotype that was different from that of both parents).

6 0

3 years ago

write a paragraph explaining why it is difficult to make drugs or vaccines against HIVgiven the fact that each time reverse tran

Sunny_sXe [5.5K]

Answer:

people who are HIV positive but keep the virus in check. This research stems from the International HIV Controllers Study, and researchers hope that their findings will ultimately help inform the development of new therapies and vaccines. Over the last 30 years, scientists have discovered lots of tantalizing clues about the virus, our immune system, and the interplay between the two, but a vaccine remains elusive.

Since the epidemic emerged, 25 million people have died from AIDS and 60 million have been infected with HIV, according to the Joint United Nations Programme on HIV/AIDS. AIDS was detected in California and New York in 1981, first among gay men and drug users, then in hemophiliacs who had received blood transfusions, and later in non-drug-using men, women, and children

Initially, little was known about how AIDS was transmitted, and even less was known about the virus that caused it. In 1985, the virus itself was isolated. Following this discovery, Margaret Heckler, the US Human Services Secretary at that time, famously declared, "We hope to have a vaccine [against AIDS] ready for testing in about two years."

Vaccines have worked well against once widespread diseases like smallpox and polio. After the AIDS virus was found, many people, including many scientists, thought AIDS would be added to the list. Vaccines mimic natural infections, during which the body produces antibodies that kill the virus. But unlike smallpox or polio, HIV doesn’t stimulate this kind of response – our immune systems are generally blind to the virus and unable to launch an effective antibody attack. Other challenges that scientists face as they try to create a vaccine include a lack of good animal models to study and the virus's ability to constantly change and mutate. Additionally, although controllers can keep levels of the virus low, no one has ever fully recovered from HIV infection. This means there's no natural, winning strategy for scientists to study and try to elicit.

Results from previous efforts to build a vaccine have been disappointing. Last year, an HIV vaccine trial in Thailand produced unimpressive results – by some measures, the vaccine reduced the chances of infection by 30 percent at most.

But this summer, scientists discovered three powerful antibodies against HIV and efforts are now underway to transform this discovery into treatment.

In addition to approaches that try to stimulate antibody immunity, researchers are also looking for ways to stimulate cellular immunity, or activate the other weapons in the immune system’s arsenal, like macrophages, natural killer cells, T cells, and more. Alerting the body’s immune system to HIV’s invasion may not prevent infection, but it could inhibit the disease’s progression and keep viral populations so low that there might be less risk of transmission.

One vaccine developed using this approach failed in trials, appearing to even increase some participants' susceptibility to the virus. But knowledge of what happened in that trial may help scientists create a more effective vaccine that targets cellular immunity

By looking at the interaction between the virus and hosts who are able to hold the virus at bay without the help of medicine, researchers hope to learn more about how to fight the virus. New clues from the viral and host genome may help lay a foundation for future means of combating HIV.

Explanation:

4 0

3 years ago

When looking at genetic traits Mendel experimented with pea plants. One of the traits he looked at was flower color. If we said

GarryVolchara [31]

A) genotype

Because the genotype means the genetic make-up of the cell, so saying that the genes of the plant are homozygous dominant show this genetic make-up of the plant.

5 0

4 years ago

Which prediction will most likely describe how friction will affect her findings? The distance for Trial 3 will be greater than

Juliette [100K]

The complete question is :

Charlie is investigating friction. She will use the same amount of force to push two wooden balls across two level surfaces. Then she will record her results in the table below.

Which prediction will most likely describe how friction will affect her findings?

Answer:

The distance for Trial 3 will be greater than the distance for Trial 4 because the difference in surface roughness will affect friction.

Explanation:

The frictional force depends greatly on the roughness of the body surfaces. It acts opposite to the direction of motion when two body surfaces have a relative motion between them.

In the context, equal mount of force is applied to push the wooden balls. So the net force which acts on the balls are :

F' = F - f

Here, F = the force applied

f = force of friction

And f = μ.N (N = reaction force)

Here μ is the coefficient of friction that depends on the surface roughness. The frictional force will be less when the surfaces are smooth. Thus for the trails 3 and trial 4, the distance for trail 3 would be greater than trail 4 as the surface is polished and would offer less friction.

8 0

3 years ago