<span>The trait that is ancestral to all chordates is the presence of a notochord...the others are gill slits and nerve chord</span>
17=3
18=4
I'm not that sure about 17, but I think it's right
Answer:
The basic repeating unit of nucleic acids are known as nucleotides. A nucleotide consists of three distinct chemical groups, a 5-carbon sugar (ribose or deoxyribose), a nitrogen-rich base - (cytosine (C), guanine (G), adenine (A), thymine (T) in DNA or uracil (U) instead of T (in RNA), and phosphate.
The type of stimulus following a behavior removes something that is unpleasant is the negative reinforcer.
Stimulus is any signal. This can be in the form of touch, smell, taste, etc. This stimulus triggers the nerve cells of the body that send to signals to the brain to generate a response. For example, when one person touches a hot utensil, the touch of heat acts as a stimulus, where the brain sends response in the form of instantly removal of the hand.
Negative reinforcement is the response towards a stimuli that has not yet been received. For example, taking a medicine before any disease appears is the acts of negative reinforcement.
To know more about negative reinforcement, here
brainly.com/question/14299460
#SPJ4
A downside to this mutant corn wohld be that it would give rise to a presticide-immune strain of the certain insect.
All the non-immune bugs would die, leaving the few immune ones to reproduce. That would result in a overpopulation of immune super-bug that would still be able to go ham on the large, GMO corn, like nothing happened, and still go on to affect native plant populations. That can become a huge problem.
Hope that helped!
