When the only force acting<span> on a falling </span>object<span> is </span>gravity<span>, the </span>object<span> is said to be in free fall. </span>force<span> of </span>gravity<span> is an unbalanced </span>force<span>, which causes an </span>object<span> to accelerate. Near the surface of Earth, the acceleration due to </span>gravity<span> is 9.8 m/s2.</span>
The superior vena cava is located in the upper chest region and is formed by the joining of the brachiocephalic veins. These veins drain blood from the upper body regions including the head, neck, and chest. It is bordered by heart structures such as the aorta and pulmonary artery.
The superior vena cava (and inferior vena cava) are veins that return deoxygenated blood from circulation in the body and empty it into the right atrium.
Answer:
Salivating at the sight of food is an example of unconditioned response.
Evolution can also influence the acquisition of conditioned/learned response.
Animals learn to avoid eating things that are harmful or cause illness.
Monkeys can more easily be conditioned to fear snakes than to fear koalas.
Explanation:
- <u><em>Unconditioned stimuli</em></u>: Biologically significant stimuli that provoke an unlearned or reflex reaction. For example, food is an unconditioned stimulus.
- <u><em>Conditioned stimuli</em></u>: neutral, inoquos or biologically not significant stimuli.
- <u><em>Unconditioned Responses</em></u>: Unlearned response that is triggered by reflex because of an unconditioned stimulus. An example is salivating.
- <u><em>Conditioned Responses:</em></u> These are provoked by conditioned stimuli. This refers to a learned response that reflects the association between conditioned and unconditioned stimuli.
Initially, an unconditioned stimulus does not provoke any response, but after enough exposition to conditioned and unconditioned stimuli together, the simple presence of unconditioned stimuli induces conditioned responses. In this aspect, the subject has learned to predict or to anticipate the unconditioned stimulus.
Animals also learn to avoid tastes that might cause them illness or might be harmful to them, and so they also learn to ignore visual or auditory sings that help them predict illness.
The detection of a harmful stimulus is an evolved predisposition rather than learned. Monkeys can show a detection advantage for a harmful animal such as the snake among non-harmful animals such as koalas. Indeed, snakes are an evolutionary threat stimuli in primates because most of them are poisonous.
