Scientists know that a mutation - or alteration - in a particular gene's DNA may contribute to a certain disease. However, it can be very difficult to develop a test to detect these mutations, because most large genes have many regions where mutations can occur. For example, researchers believe that mutations in the genes BRCA1 and BRCA2 cause as many as 60 percent of all cases of hereditary breast and ovarian cancers. But there is not one specific mutation responsible for all of these cases. Researchers have already discovered over 800 different mutations in BRCA1 alone.
The DNA microarray is a tool used to determine whether the DNA from a particular individual contains a mutation in genes like BRCA1and BRCA2. The chip consists of a small glass plate encased in plastic. Some companies manufacture microarrays using methods similar to those used to make computer microchips. On the surface, each chip contains thousands of short, synthetic, single-stranded DNA sequences, which together add up to the normal gene in question, and to variants (mutations) of that gene that have been found in the human population.
Human Flora
Lesson Transcript
Instructor: Rebecca Gillaspy
Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.
The amount of blood being pumped through your body changes constantly due to the demands of daily life. In this lesson, you will learn how your body adjusts the heart rate and stroke volume to increase or decrease blood flow.
Cardiac Output
The volume of blood your heart pumps per minute, known as your cardiac output, varies with the demands you put on your body. We previously learned that the cardiac output (CO) is calculated by multiplying the number of heartbeats per minute (which is your heart rate, or HR) times the volume of blood pumped out of the heart with each heartbeat (which is your stroke volume, or SV). So:
cardiac output (CO) = heart rate (HR) x stroke volume (SV)
The cardiac output of your heart is a constantly changing amount that adjusts to any physical or emotional demands you put on your body. In this lesson, we will look at some of the factors that influence your heart rate and stroke volume.
<span>The tone, before conditioned to salivation, is simply a stimuli that the dog is responding to or ignoring in it's environment. Since it has no taught reactions to this sound, it is simply part of the environment the dog is in.</span>
Answer:
D) Yellowstone Hot Spot-North American Plate
Explanation:
The first one, cause their trying to make it a positive way to reinforce. Which just means their trying to fix something again
