Answer:
DNA is double-stranded and cannot fit through the nuclear membrane; RNA is single-stranded.
Explanation:
Identify the variables.
Write out your hypothesis in an if/then format.
Gather your materials.
Analyze the data.
Write your conclusion.
The correct order of steps in an experiment would be:
An experiment is a term to refer to the process by which a hypothesis is supported/disproved. The experiments serve to explain the cause-and-effect relationship according to the results obtained.
Experimentation has some important steps that we must follow to demonstrate our ideas regarding a scientific manifestation, these steps are:
Learn more about experiments in: brainly.com/question/9199868
the purpose of valves in the heart valves is to allow blood to flow only in one direction. Valves open and close on differential pressure on each side. pulmonary and the aortic valves receive blood from the ventricles and their semilunar valves allow blood to go into the arteries and prevent back flow from the artery to the ventricles.
Answer:
Explanation:
This is usually because when they first became fossils, they embedded into the ground. Over many years afterwards, more layers came to cover that layer and so on. Newer fossils would be embedded into newer layers. That's why the older ones tend to be found the deeper you look.
Answer: Well probably because of the fact that over time the rocks stack up on top of each other because of weathering and erosion and as they stack they get deeper and deeper, so fossils that were at the top one time will slowly sink as the time progresses.
B) Polymerases can only synthesize in the 5' to 3' direction
C) There are only enough dNTP's to support quick replication on one strand, so the other strand lags behind it
D) It is necessary to "slow down" one of the strands so that replication does not occur before cells have a chance to grow
Answer:
B) Polymerases can only synthesize in the 5' to 3' direction
Explanation:
The leading strand's directionality is 3' to 5', so polymerase has no problem with replicating this one. But the lagging strand has the opposite directionality, so the polymerase must work in the opposite direction of the replication fork.In consequence, the replication process undergoes periodic breaks, and the enzymes have to stop and start again while helicase separates both strands, resulting in the polymerization of okazaki fragments.
Answer:
Mast Cells
Explanation:
Mast cells release histamine in the blood stream, when they detect a substance that triggers an allergic reaction, also called an allergen.
Air pollution is one of the most serious threats facing national parks, harming visitors’ health, clouding scenic views and altering our climate.The air pollution affecting national parks — and the rest of the country — results from the burning of fossil fuels by power plants, oil and gas development, vehicles, agriculture, industrial emissions, and other sources. NPCA works to make sure our nation’s air laws are strong, to hold polluters and government accountable to those laws, and ultimately, to reduce the air pollution that harms our parks, climate and communities.
The Clean Air Act – which has helped improve air quality throughout the nation and the National Park System – is now under consistent threat as the Environmental Protection Agency works to roll back regulations, attack the use of science and offer polluters loopholes. NPCA advocates to defend and strengthen the clean air laws that protect park skies. We speak out for science and guard against policies driven only by politics and private industry.
Picture park skies free of pollution. While this sadly isn’t the case today, NPCA strives to make sure that parks are on the right track and that air pollution harming parks is reduced. We do this by helping to secure strong state plans to limit haze-causing and climate-altering pollution, and by defending existing plans – in court, if necessary.
Clean air laws are meaningless if polluters and the government don’t follow them. NPCA vigilantly monitors for sources that violate their permits or when officials aren’t following through on the safeguards in place to protect parks. We also look for opportunities to collaborate and work in state, local or regional processes to prevent threats of new pollution and help reduce harmful emissions. Learn about our work in California and Utah.