D. Myosin and actin do not fully detach, so the muscle cannot relax.
Answer:
A. Urethra
Explanation:
The part highlighted below is also known as the Urethra, or the tube in which the urine or semen travels in the male reproductive system! :)
Answer:
The correct answer is - option B. They are small because they lack a nucleus.
Explanation:
Red blood cells or erythrocytes are specialized cell that produce in bone marrow and have specific role such as carrying oxygen from lungs to deliver it to the various organs and carry out carbon dioxide.
In mammals these cells lack cell organelles such as nucleus and mitochondria, a major factor that determined its smaller size. The size of RBC are move through narrow vessels throughout a organism because of its specific size and shape that provide it space for hemoglobin and allow to be flexible and bend to move through narrow vessels.
Thus, the correct answer is : option B. They are small because they lack a nucleus.
The answer is “Organisms that contain functional recombinant DNA