Explain the significance of the blood painted onto the door frames in Exodus 12.

The Jews were in slavery to the Egyptians at the time of the writing of Exodus 12. Pharaoh had threatened the life of Moses. The Lord had told Moses and Aaron that the Angel of Death would pass through Egypt, striking the firstborn of Egypt. God instructed Moses to tell the Israelites that "on the 10th day of the Jewish New Year each man was to choose a lamb, without defect, and care for it until the 14th day, On that day each family was the slaughter the chosen lamb. Thee then to take the blood and place it on both sides of the door and over the top of the door. The blood would symbolizes a sacrifice offered as a substitute, one life laid down for another. As the Angel of Death passed through Egypt, the firstborn child of those Jews who had the blood on the top of the door and door posts would be passed over. This was the institution of the first Passover. The Lord would pass over and not destroy the occupants of the houses that were under the sign of blood. Blood represents redemption. It was also a symbol of the sacrifice Jesus Christ.

Resources:

Barker, K.L, Stek, J.H., Strauss, M.L, and Youngblood, R.F (2008). NIV Study Bible. Grand Rapids, MI: Zondervan.

Why did Emperor Theodosius allow some barbarians into the Roman Empire?

Emperor Theodosius the Great (347-395 AD) spent the early years of his reign fighting against barbarian invaders and settlers in the East (specifically the Visigoths). However, he eventually realized he could not contain the relentless Visigoth influx. Thus, he signed a peace treaty with them in 382.

According to the terms of this treaty, the barbarians were allowed to have their own land (Thrace) within the Roman Empire. In return, the barbarians submitted to the rule of Theodosius and furnished troops for his army.

This treaty brought a double benefit to the Romans. First, they were able to divert money and resources away from the war with the Visigoths. Second, the Visigoths were experienced fighters, so their enrollment in the Roman military greatly increased the strength of the Roman army.

You are heating water in a beaker. How would you describe the change in energy and speed of the water molecules as the water gets hotter?...

The correct answer is A. As the temperature of the water in the beaker increases, both the energy and speed of the molecules increases.

Temperature, energy and molecular speed are all related. Temperature is the measure of average kinetic energy of molecules. The kinetic energy of an individual molecule is one half the product of its mass and the square of its velocity:

KE = 1/2 mv^2

As the water molecules absorb heat energy they move faster. Heat is conducted to the water molecules by collisions with faster moving particles. The speed and therefore the temperature of the water molecules continues to increase until the boiling point is reached. At that point the faster moving molecules escape into the gas phase so their speeds are no longer part of the average. The avarage speed kinetic energy of the molecules still in the liquid phase remains constant as the liquid boils so no increase in temperature is observed.

How pheromones could be used to control insects on a crop?

Many organisms respond to signals other than sight or sound waves. There are chemicals called pheromones that affect organisms within that species in such activities as mating, finding food, etc. 

Pheromones usually can be detected in the air and last a long time and persist over a long range. Male insects can locate a female ready to mate by the pheromones in the air that act like a beacon directing the male to the female. 

A pheromone that has been identified in a species of insect pests could then be manufactured and subsequently released to lure males to follow the trail. At the end of the trail a trap is set to capture and kill the males or to "scout" them to identify their active times in order to optimize prudent pesticide use. Pheromone traps may also be used in conjunction with chemosterilants to which males are drawn by the sex pheromones in the traps. The chemosterilants act upon the males, that then return in a sterilized condition to the fields where mating produces nonviable eggs and results in population reduction (Dr. J. P. Sharma, Comprehensive Biology XII).  

Pheromones can be released over a large area which masks a species' pheromones, confusing the males, and this will prevent mating between males and females. This technique causes confusion where males seek and never actually find any mates.

An advantage to using an insect pest's unique pheromone to lure it to a trap or to confuse the mating process is that it only affects the pest and doesn't harm the other members of the community.

In contrast, traditional insecticides which are released onto a field affect many different organisms, not merely the targeted pest. For instance, the frogs that eat the grasshoppers that ate leaves sprayed with chemical insecticides will all have these chemicals in their tissues due to bioaccumulation through eating and being eaten in turn. These chemicals may be long-lasting and persistent in the environment and can run off into nearby lakes and streams, affecting aquatic life.

In Harper Lee's To Kill a Mockingbird, what passages from the trial show unfairness?

In Harper Lee's To Kill a Mockingbird, Atticus's closing speech to the jury is full of passages that speak of the unfairness of the trial.

To begin with, Atticus points out that the case should never have gone to trial because there was no, as Atticus phrases it, "corroborative evidence," meaning evidence that confirms other evidence (Ch. 20). The only evidence being used in the trial was the testimonies of witnesses whose credibility had been called into question upon cross-examination. Hence, the first thing unfair about the trial is that, as Atticus points out, "...absence of any corroborative evidence, [Tom Robinson] was indicted on a capital charge and is now on trial for his life ..." (Ch. 20).

A second unfair aspect about the trial is that, as Atticus proves, any physical evidence points to Robinson's innocence and Bob Ewell's guilt. Atticus points out in his closing remarks to the jury, "We don't know [what Mayella's father did to her], but there is circumstantial evidence to indicate that Mayella Ewell was beaten savagely by someone who led almost exclusively with this left" (Ch. 20). Atticus further points out that Robinson could not even use his crippled left hand well enough to take the oath. Hence, the trial is unfair because all evidence shows that Robinson could not possibly have committed the crime he is being accused of.

Why is it important to vote in our goverment?

Voting by citizens is very important in our government system. Since we have a democratic republic, we vote for leaders to represent us in government and to vote on issues for us. If people don’t vote for their elected leaders, they are allowing a smaller group of people to determine who their leaders will be and possibly what policies would be enacted. By voting, we are sending a message to our elected officials. If they don’t listen to our concerns, they may get voted out of office. However, if not many people vote, they may get elected easily and continue to operate as they had in the past. We also are telling them with our vote how we think they are doing as an elected official.

Voting is also one of our responsibilities as a citizen. It is important to fulfill our responsibilities as citizens. There are many people in the world that would love to be able to choose their leaders in free elections. We have that in place here, and it is important not to ignore that responsibility.

Finally, sometimes the vote of the people determines if something will or will not happen. If there is a binding referendum on the ballot, we determine if that referendum passes or fails. It is important that we take our voting responsibility seriously so we can make informed choices, elect good leaders, and possibly determine policy.

What do fossil fuels and renewable energy sources have in common?

Fossil fuels, also known as non-renewable sources of energy, include fuels like coal, petroleum, natural gas, etc. These fuels have taken millions of years to form and are thus in a limited quantity, and will run out depending upon our rate of consumption. Renewable sources, on the other hand, are not in limited quantity and can be replaced. Examples of renewable sources include, solar energy, wind power, tidal energy, etc. Both the renewable and non-renewable sources of energy are used for energy generation: as electricity and as heat. Currently, fossil fuels fulfill most of our energy needs, but the share of renewable sources is rapidly rising. Another common feature of both the fossil fuels and renewable sources is that they are mostly forms of sun's energy (an exception is geothermal energy). Fossil fuels are result of fossilization of plants and animals, which used sun's energy to survive, when they were alive. Similarly, solar power is direct use of sun's energy, while winds are generated by sun's energy, etc.

Hope this helps.