<span>The thymus.The thymus plays an important role in the development of T-lymphocytes which is an important type of white blood cell. It reaches maximum development at puberty and then the thymus begins to get atrophied (the shrinking of the thymus with age) and then the thymic stroma is replaced by fat tissue. Loss of thymic function is thought to contribute to weaker immune system of the elderly, increasing instances of diseases such as cancers and other infections.</span>
Answer:
Your answer is 2.
Explanation:
To calculate the mechanical advantage of a pulley you simply have to count the number of rope sections that support whatever object you are lifting (not counting the rope that is attached to the effort). For example, in a one pulley system the MA is 1. In a two pulley system the MA is 2.
Answer:
b) false
Explanation:
The given statement is false. the selection process used by the rancher is an example of artificial selection and not natural selection.
Artificial selection is defined as the selection process done by humans on the basis of desirable characters while in natural selection the selection is based on the adaptive characteristics of animals. In the given example rancher choses a desirable character of chicken that lays more eggs.
Hence, the given statement is "false".
Answer:
Reflexes are not a function of the spinal cord.
Explanation:
The spinal cord is part of the central nervous system and is made up of neurons that go along it (from the end of the brain stem almost to the bottom of the spine).
The spinal cord receives incoming messages from the peripheral nervous system (including the sensory neurons) and pass on messages from the brain to efferent neurons (motor neurons at muscles).
The spinal cord contributes to learning as it passes on the info received from sensory neurons (that there is an obstacle in the path) to the brain and passes on the response from the brain to the muscles (to lift the foot up higher).
The spinal cord is essential for integration as it passes on sensory information to the brain to determine motor output.
Reflexes are when sensory information is quickly sent straight to motor neurons to move. It does not need to go to the brain (hence does not need to go to the spinal cord) for the reaction as it would be too slow. This is seen when someone who is paraplegic (paralysed at lower torso) can still move their leg in response to the doctor tapping their knee even when they cannot forcibly move their legs.
Therefore reflexes are not a function of the spinal cord.
