Answer:
the answers are b, c, and d. hope this helped!
Explanation:i just took the quiz on usa test prep and got 100.
1)
To feel an impulse, the receptor must be sent a signal to the brain where it could be interpreted. The signal should be caught by the receptor, send into the spinal cord, then arrives at the brain.
1. Object touch the heel
2. impulses generated in the receptor cells
3. impulses transmitted through a sensory neuron
4. impulses transmitted through neurons in the spinal cord
5. impulses reach the brain
6. brain process the impulses
7. you feel the object touching your heel
2)
Nerves
Spinal cord
Brain
The nervous system is made of central nervous system and peripheral nervous system. The peripheral nervous system is made of the network of nerves. The central nervous system is the brain and spinal cord that will receive impulse and send a response afterward. While brain could send the various signal, spinal cord could only send responses for reflexes.
3)
a. the diagram is showing Neuron cell
The nervous system is made up of multiple neuron cells. The neuron cells are specialized in sending a signal. It has a long axon that could deliver the signal far away. The signal is only one way though, so you will need a different neuron for receiving receptor signal and sending a response signal.
b. Two missing labels in the picture would be: axon.
It seems both of the label pointing out to the axon of the nerve cell. Since both of it pointing the same neuron cell, it should have the same name. Axon has a role in delivering nutrient and signal across the body.
c. Myelin sheath will allow the signal to run faster. This will help in a process that needs speed like reflexes. The sheath will cover a part of the neuron and prevent the ion exchange. Myelin sheath stop in some part called node of Ranvier. This will allow the action potential to "leap" from node to node, make it travel much faster.
Answer:
It plays a vital role in the carbon cycle because it releases carbon dioxide into the atmosphere.
Explanation:
Science.
Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
