<span>The avian heart has evolved into a large and powerful organ with rapid muscular contractions. Generally the smaller the species the larger the relative heart size. Generally birds have hearts larger and ones that beat faster than mammals. The human heart weight amounts to .42 percent of body weight and the pulse rate at rest averages 72 beats per minute. The House Sparrow's heart constitutes 1.68 percent of the body weight and the pulse rate at rest averages 460 beats per minute. In the Ruby-throated Hummingbird these figures rise to 2.37 percent and a pulse rate of 615.</span>
<span>The correct answer are: the testes, the ovary and the adrenal gland.</span>
Secondary sex characteristics are characteristics that appear during puberty in humans when hormone level rises. Testosterone(testes) and estrogen(ovary) have the main influence in manifesting secondary sex characteristics. The function of the adrenal gland is to produce androgens: DHEA (dehydroepiandrosterone) which can be intermediate in the biosynthesis of the androgen and estrogen sex steroids.
Answer:
What do fossils provide evidence of?
-Fossils provide evidence of the earliest forms of life.
Which of the terms is used to describe the difference between them?
- Evolution