Answer:
B. Amplitude: 30cm; wavelength: 110cm
<u>Answer</u>: an all or none response
According to the all-or-none law, it a certain threshol is crossed by a stimulus' strenght, it will cause a response in the nerve cell or muscle fiber. However, the strenght of the response will always be the same and will not vary with different stimulus strengths. The only requirement is for the threshold to be crossed.
B. The nervous system collects and responds to information about the external and internal environment.
Answer: Option D " all of the above "
Explanation: DNA can be a great source of information when used as a forensic evidence. This technique has many advantages and disadvantages when used as a source of information in case of crime.
Identical twins: There are some common fragments of DNA that is same in identical twins so it can be a difficulty in deciding the criminal.
Not enough of a sample: DNA should be present in a detectable amount to be used an sample for evidence, less than this detectable amount is a waste and cannot be used as a sample for evidence.
Contaminated and degraded sample: If the sample of DNA is contaminated or degraded then the result might be incorrect and might not be used as a sample for forensic evidence.
Hence, the correct answers are all of the above.
