Difference threshold is a minimum alteration in sensory intensity that is noticeable to an observer and can be coded into neural messages. Different threshold is the lowest level of encouragement that is essential to sense that a modification has happened the difference in the intensity between two stimuli that is necessary to yield a just notable difference also known as JND. The just notable difference depends not only on the intensity of the new stimulus but also on the level of stimulation already present which is the more intense the existing stimulus the larger the change must be to be noticeable.
Natural selection it has to be 20 characters so disreguard the rest
False
Homeostasis is defined as the process of resisting change in order to maintain a stable environment. It typically involves negative feedback loops as these loops prohibits the change to occur in the human body system and maintain a constant internal environment. While positive feedback is the process of amplifying the stimulus produced within the body.
Homeostasis is thus regulated by negative feedback loops and rearely regulated by the positive feedback loops.
Answer: The correct answer is-
A. organs, but no true body cavity.
Based on the presence of body cavity ( also called coelom), multicellular animals can be classified as acoelomates ( no true body cavity), coelomates ( having true body cavity), pseudocoelomates ( false body cavity).
Roundworms are pseudocoelomic. This means that organs are present but the body cavity is not lined by mesodermal epithelium.
Body cavity is present between the external wall of body and the intestine and it baths the different body organs.
Thus, option A) is the right answer.