The formation of new viruses.
Smooth muscles- protects the organs
Cardiac muscle- around the heart
And skeletal
The removal of the cell membrane.
The membrane regulates homeostasis by letting "stuff" (general term) in and out of the cell.
Human migration is the movement over long distances, movement from one country/region to another ) by people . Humans moved because of the c<span>hanging climate and landscape and inadequate food supply. </span>The first human movement was t<span>he movement of </span>Homo erectus<span> out of Africa across </span>Eurasia<span> about 1.75 million years ago. </span>
Than industrialization<span> encouraged migration wherever it appeared.
Wars also created migration. (</span><span>The First and Second World Wars, and wars, genocides, and crises sparked by them, lead to migrations).</span>
Answer:
a) stomata
Explanation:
The stomata are little pores / doorways / openings that have the express purpose of allowing gases in and out. Without this, plants would not be able to fix carbon, which is essential in respiration.
Why not c or b: The xylem and phloem channel water through the plant, not gases.
Why not d: The cuticle is the waxy outer layer of the leaf meant to protect it, not allow gases through.