JeffreyScudder
Biology AP Test practice Essays

1.)	

	Hypothesis - If The intensity of light on a Brasc. Rappa Plant is high, then more photosynthesis will occur as opposed to a lesser intensity of light.

	For the experiment I would set up two Brasc. Rappa plants in equal containers with equal food and equal soil in equal environments. I would expose each one to light for 3 hours a day at the same time periods, but Plant A would have the light quality of one candle power, while plant B would have the quality of 10 candle power. I would continue this for 10 days and measure the plants each day by mass. The larger the plant grows, the more photosynthesis is obviously occuring, and this is how photosynthesis can be measured.

	For results I would expect that Plant A would grow less than Plant B, because Plant A was not exposed to as high of an intensity, and therefore the light cannot shine completely through the leaves of Plant A, so some of the chloroplasts and cells do not receive it and therefore do nor perform photosynthesis.

2.)

	a.) Plant cells communicate by passing material from one to another. They have gated channels in their cell walls, and with these they can transport water, messages or food. Plant cells must communicate so that water and materials can get to all cells in the plant.

	c.) A neuron gets a signal from the Axon and the electric signal goes through the long neuron's tail until it gets to the end of the neuron, the nephron. The signal goes to the nephron and is released where it goes to another Axon head and through the next neuron and schwann cells in the tail.

	d.) An endocrine gland cell communicates with it's target cell by sending out receptors to get the target cell and the endocrine cell gets more cells from the gland to reach the target.

3.)

This classification scheme presents different conclusions about the relationships among living organisms because unlike the 5 kingdom classification system, this three domain system is organized by type of cell and cell nucleus, which is probably more accurate because the organisms evolved from single celled organisms that were once seperated through evolution.

Three kinds of evidence are vestigial structures, or structures that are similar in many creatures of the same kingdom, but not necesarily used. Fossils can show us that these domains may have evolved together at different parts of the world and thus contributes to the system as well. The nucleus and cell structure of each class is also somewhat varied, and this is technically the most important piece of evidence that the grouping is based on.

The universal ancestor, probably did not have a nucleus, was single celled, and had no functioning organelles. It was probably a membrane with genetic material and it was most likely RNA. These are probably characteristics because all the domains have cells like this, or possibly once had cells like this.

4.)	

	DNA copies itself precisely through DNA transcription, where it unwinds, and DNA polymerase comes in and copies the DNA. The method used rarely wields error because the DNA checks itself to make sure its correct. DNA is stable but able to be changed because of meiosis, where certain sets of chromosones can swap and this can bring about different strand combinations and therefore more genetic variation in a species. DNA is complex enough to determine and organisms phenotype. Each codon contains even more data, and the double helix format of DNA allows the data to be compact and safe.

	DNA copies itself precisely, and this itself is evidence that DNA is the hereditary material. When DNA is copied, an an organism is cloned, the same organisms come about. DNA has been proven to contain almost all of the information that hereditary material is expected to have. All genetic variation in humans and reproduction is due to changes in our DNA. This proves DNA is the genetic and hereditary material.