Protein channels + no energy spent + following concentration gradient = passive transport via facilitated diffusion :)
<u>Answer</u>:
Vestigial organs are those organs that were present in the past ancestors but absent in their present generations. Vestigial organs are not leftover of evolution because they are evolved to perform a different function.
<u>Explanation</u>:
For example, an appendix is considered as a vestigial organ but it helps in storing good bacteria and plays a vital role in the immune system. These vestigial organs are the product of changing the environment and adaptation to the changing environment. Due to natural selection some specific traits have been passed down to generations which helped the animals to survive in those conditions. The other examples of vestigial organs are wisdom teeth coccyx, tonsils, several genes in the chromosomes and our hair.
An activity recommended when working with free weights is to do like an overhead press ie with the barbell, lift it up to the waist, then thrust it into the air higher than the head and lower it in the same step by step fashion. With the dumbells, one can use a bench and lie back on it and do a pec dec fly bringing the dumbbells towards each other.
