Answer:
a. Yes. It is possible for them to produce a child with red-green colorblindness.
Explanation:
Color blindness is a change in vision that is characterized by the inability to distinguish some colors, especially green from red. Like hemophilia, color blindness is an example of inheritance linked to sex.
Color blindness is determined by an X-linked recessive gene, symbolized by Xd while the dominant allele gene, which conditions normal vision, is symbolized by XD.
Thus we can conclude that it is possible that the couple, exposed in the question, have a child with red-green color blindness. As the child's father already has the recessive gene, which is likely to be passed on to the child, if the mother also has the recessive gene for color blindness, the child is likely to develop red green color blindness.
There are two systems in the human body that are responsible for the coordination between the functions of different systems to achieve the unity of the living organism's body. These two systems are the nervous system and the endocrine system. The action of the nervous system is fast and takes a short time, while the action of the endocrine system is slow and takes a long time.
The functional unit of the nervous system is the nerve cell or the neuron. The neuron consists of a cell body and the axon. The cell body starts with the dendrites that receive the messages or the impulses from other neurons or from different sense organs or receptors. These impulses are then transmitted through the cell body. The cell body contains a nucleus and different organelles which help the nerve cell to perform its functions. The nerve impulse is then transmitted to the axon.
The axon is an extension from the cell body. There are some cells called Schwan cells that secrete a myelin sheath to insulate the axon from the surrounding medium. The insulated axons have more ability to conduct the impulses than non-insulated axons. The axon ends with the terminal arborizations. The terminal arborizations of a nerve cell connect to the dendrites of the next cell or to the afferent organ. The gaps between the dendrites and the terminal arborizations are called the synapses.
The nerve impulse is an electrochemical phenomenon i.e. an electrical phenomenon with a chemical nature. The membrane of the axon acts as a barrier between an outside positively charged medium and an inside negatively charged medium. This makes a potential difference of -70mV. This state is called the resting potential. When the membrane is subjected to a stimulus, the positive charges enter to inside and the negative charges exit to the outside. The potential difference now becomes +40mV. This state is called the depolarization state. The point of stimulation acts as a new stimulus for the next point and so on. The membrane sooner gains its permeability again and the positive charges return to the outside and the negative charges to inside. This state is called repolarization.
The nerve impulse reaches the synapse. There are some neurotransmitters that are excited by the nerve impulse coming and carry the message across the membrane. Some receptors receive theses neurotransmitters on the dendrites of the next neuron. These receptors act as a stimulus for the new cell.
Answer:
If two similar looking species are able to produce fertile and viable offspring, then they belong to the same species.
Explanation:
According to the biological species concept , organisms are said to be of same species if they are able to interbreed and produce fertile and viable offspring.
In case if two species are closely related on the basis of external features, then they must be allowed to mate. The offspring produced in the first generation mating must be allowed to mate again. If in the second generation offspring are produced, then it shall prove that the two similar looking organisms are able to produce viable and fertile offspring thereby establishing the fact that they belong to same species.
<span>C. Blood components are continuously produced in the bone marrow.</span>
