Photosynthesis
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Because endocrine signals are broadcast throughout the body, alls cells will respond to the hormonal signal..
B. False
The correct answer is: d. membrane thickness
Cholesterol is the second major lipid in the structure of the cell membrane (phospholipids are the major lipid components).
Cholesterol is rigid, so it gives the cell membrane extra support (strength and hardness) by immobilizing some of the lipid molecules around them. This rigidity makes it harder for small molecules to pass through the membrane, so it also has the influence on cell membrane’s permeability (the membrane becomes effective barrier to ions).
Cell membrane’s fluidity is also under the influence of the cholesterol which helps generate some extra space between the lipids allowing them to move freely throughout the membrane.
Answer:
A neuron that has only one axon but several dendrites is classified as:
a. multipolar neuron.
Explanation:
- The neurons are the fundamental unit of the nervous system.
- The nervous system consist of only two types of cell; neurons and neuroglia.
- Neurons are specialized to respond to physical and chemical stimuli, conduct nerve impulse and release neurotransmitter , while the neuroglia supports , nourish and protect the neuron.
- Most neurons have three parts: a cell body, dendrites and axon.
- Neurons show a great diversity in size and shape, and are classified on the basis of structure and function.
On the Basis of structure the neurons are classified as: unipolar, bipolar and multipolar. (Multidendritic neurons are studied in <em>Drosophilla </em>and are reported to be a result of misexpressed<em> gene</em>)..
- Multipolar neurons are the most common type of neurons in the brain and spinal cord and have several dendritic processes and one axon.
- Bipolar neurons are found in retina of the eye, in the inner ear and in the olfactory area of the brain and are characterized by one dendrite and one axon.
- Uni-polar neurons have single processes extending from the cell body which divide into two branches.
On the basis of function neurons are classified as; sensory, motor and association neurons.
