The chronological order of the response brought about by the nervous system is as follows.
1. Sensory receptors in the arteries detect low oxygen levels.
2. Sensory neurons generate an impulse.
3. The central nervous system relays an impulse to certain brain regions.
4. The brain sends signals through motor neurons.
5. Isabel's breathing rate increases.
The response to a stimulus is called a reflex action and the pathway traveled by the reflex action is called the reflex arch. A reflex action is an automatic involuntary response to a stimulus which minimizes any damage to the body. During conditions of low levels of oxygen in the body, the receptors detect the stimulus of low oxygen levels which could pose a threat to the individual and sensory neurons generate an impulse. It reaches the central nervous system and then the brain. In turn, brain sends signals through the motor neurons that carry a message and help in increasing the breathing rate of Isabel.
Homologous chromosomes pair up and exchange segments of DNA.
Option A
<h3><u>Explanation:</u></h3>
Crossing over is an event of Prophase 1 of meiosis 1. It occurs in the zygotene phase of prophase 1. Here the homologous chromosome pairs get very close together and gets packed within protein coat. The enzymes randomly cut the DNA segments from both chromosomes at same loci and exchange them with each other. This results in the exchange of genes between the two chromosomes. This is how the variation comes to place between offsprings of the same individuals. The crossing over results to form X shaped intersections between homologous pair of chromosomes which is called as chaismata. This phase occurs in pachytene phase and is visible in diplotene phase when the protein coat dissolves.
It would be uracil (C)
thymine would be complementary to adenine in DNA but because it is RNA it is replaced by uracil.
A - 9%
T - 9%
C - 41%
G - 41%
Total is equal to 100%
Answer:
Secondary succession
Explanation:
When a previously occupied area gets colonized by a new dominant group of species or communities, this is known as secondary succession. In secondary succession, new residents take the place of earlier groups in a habitat that has been affected by an ecological disturbance.
