Answer: The correct answer is-
an agent that causes a mutation in DNA.
Mutagen is an agent or a substance that causes permanent change in the genetic material of living organisms ( DNA, deoxyribonucleic acid). This process is called mutation.
A mutagen can be a chemical, physical or biological agent that causes mutation in the DNA.
Example- Physical agents such as -
- Ionizing radiations like alpha particles, gamma rays, X-rays that brings break in the DNA and cause other damages.
- Ultraviolet radiations that creates pyrimidine dimers ( T=T) and causes replication errors if damage is not repaired.
PRIMARY GROWTH
1) apical meristem
3) elongation
5) increases exposure to light
9) occurs in plants that live only one year
SECONDARY GROWTH
2) cork cambium
4) provides structural support
6) increases vascular flow
<span>7) growth in thickness
</span>10) lateral meristem
11) vascular cambium
BOTH
8) occurs in plants that live many years.
NEITHER
Both black holes and neutron stars are corpses of stars that died in catastrophic explosions known as supernovas, outbursts that can make a star briefly outshine all of the other stars in its galaxy. When a star goes supernova, the core of its remains collapses under the strength of its own gravitational pull.
Answer;
A) Blood pressure decreases greatly; blood flow to the heart is inadequate, and blood pressure decreases.
Explanation;
-With negative feedback, the output reduces the original effect of the stimulus. While in a positive feedback system, the output enhances the original stimulus.
-Negative feedback is the most commonly used feedback loop in the body. Negative feedback is used to negate or counteract a stimulus without completely eradicating it.
-One key difference between the two feedback is that positive feedback loops are used to eradicate a stimulus. Another key difference is that responses through positive feedback become more amplified over time. So once a stimulus activates a positive feedback loop it is not turned off until the stimulus is completely removed.
