Answer: After 3 rounds, 8 segments having 2 original strands on different segments will be present.
Explanation:
The polymerase chain reaction selectively and repeatedly copy the double stranded DNA (dsDNA) in the PCR machine.
1st round:
Single piece of double stranded DNA (dsDNA) unwinds in two seperate strands, before complementary nucleotides are synthesized to establish double helix.
2nd round:
The two dsDNA yields 4 segments before complementary nucleotides are synthesized
3rd round:
The four dsDNA yields 8 segments before complementary nucleotides are synthesized.
Therefore, at the end of 3 rounds, the two original strands will be present on the 8 different segments of copied DNA.
Answer:
After 6000 years, approximately 500 atoms of carbon-14 will be left in the femur bone of an animal which had 1000 atoms of carbon-14 when the animal died.
Explanation:
The half-life of a radioactive isotope of an element is the time taken for half the atoms present in a given amount of the element to undergo decay or disintegration. For example, the half-life of carbon-14 isotope is 5730 years. This means that, if there are 100 atoms of carbon-14 present in a given sample of a material, in the next 5730 years, approximately, 50 atoms of carbon-14 will be left in the material.
Since the half-life of radioactive isotopes are constant, these radioactive isotopes are used in the determining the ages of ancient life-forms as well as rocks.
In the given example, after 6000 years, approximately 500 atoms of carbon-14 will be left in the femur bone of an animal which had 1000 atoms of carbon-14 when the animal died.
Answer:
the answer to it is 1,199,295
Answer: Gastroenterology
Explanation: Gastroenterology is a branch of medicine concerned with digestive diseases. The practice of gastroenterology concentrates on the diagnosis and treatment of diseases involving the esophagus, stomach, small intestine, and large intestine (colon), liver, and pancreas. Examples of conditions treated: Abdominal pain.
More than 4.2 million Americans aged 40 years and older are either legally blind (having best-corrected visual acuity of 6/60 or worse (=20/200) in the better-seeing eye) or are with low vision (having best-corrected visual acuity less than 6/12 (<20/40) in the better-seeing eye, excluding those who were categorized as being blind).
The leading causes of blindness and low vision in the United States are primarily age-related eye diseases such as age-related macular degeneration, cataract, diabetic retinopathy, and glaucoma. Other common eye disorders include amblyopia and strabismus.
Click here to see the anatomy the eye and how the eyes work.external icon
Refractive Errors
Refractive Errors
Refractive errors are the most frequent eye problems in the United States. Refractive errors include myopia (near-sightedness), hyperopia (farsightedness), astigmatism (distorted vision at all distances), and presbyopia that occurs between age 40–50 years (loss of the ability to focus up close, inability to read letters of the phone book, need to hold newspaper farther away to see clearly) can be corrected by eyeglasses, contact lenses, or in some cases surgery. The National Eye Institute states that proper refractive correction could improve vision among 150 million Americans.
