Answer:
aortic arches (earthworms)
Explanation:
Earthworms vessels link together
Answer:by being produced in the testes outside the body
Explanation: spermatogenesis is the production of male gamates,the sperm.this process occurs in the seminiferous tubules in the testes.epithelial cells produces the primary spermatocyte which divides to give a secondary spermatocyte.
The secondary spermatocyte divides to form spermatids,which differentiates to form the spermatozoons.
Testis is housed in the scrotal sac.
Sperm production is sensitive to temperature. Too high temperature can cause formation of abnormal cells . As a result the scrotal sac is located outside the body
3 inches per year best represents the average rate at which infants grow in height during the first four years after birth. The correct option among all the options that are given in the question is the second option or option "b". The other choices given in the question seems quiet absurd. So by the method of elimination, one can say that option "b" is correct.