Answer:
The correct answer will be option A.
Explanation:
The electrical impulses are generated in the sino-atrial node or SA node, a mass of cells which generates impulse in the upper atrium.
This electrical impulse transmits from the sino-atrial node to the atrio-ventricular node in the lower portion of the upper atrium through the internodal pathway- the pathway composed of atrial cells.
Once the impulse reaches the AV node, it is transferred to the ventricular portion of the heart through Bundle of His presence in the ventricular septum. This bundle of his divides into left and right ventricles through bundle branches and stimulates both the ventricles.
Thus, option-A is the correct answer.
Answer:
All of the statements are true.
The X chromosome is one of the two sex chromosomes of humans and some animals (the other sex chromosome is the Y chromosome). Men have a single X chromosome and women two X chromosomes.
Diseases whose gene is localized on the X chromosome are most often transmitted in the X-linked recessive mode; some are transmitted on the dominant mode related to the X.
In this mode of inheritance, the morbid allele behaves like a recessive trait.
Women heterozygotes are not affected but can transmit the disease; they are aid to be conductive of the disease.
The disese is only manifested in male subjects (XY) with only one copy of the gene (hemizygous subjects)
Hey there!
<span>The near extinction of many bird species was caused by:
Answer: </span>
<span> use of DDT
Hope this helps
Have a great day (:
</span>
Answer:
Cilia and flagella are projections from the cell. They are made up of microtubules , as shown in this cartoon and are covered by an extension of the plasma membrane. They are motile and designed either to move the cell itself or to move substances over or around the cell.
Explanation:
