Answer:
The C horizon is located closest to the Earth's crust. Weegy
Soil is made of air, water, organic material, minerals, and weathered rock.
Answer: B.
Explanation: Cytosis in this context is the taking in, and releasing of various nutrients, proteins, toxins, etc. in and out of the cell. This is facilitated by the plasma membrane because it's our wall that surrounds the cell deciding who goes in and who goes out.
Answer:
smaller than
Explanation:
But they're nothing compared to the giants of the cellular world. ... And viruses are smaller again — they're about a hundredth the size of our cells. So we're about 100,000 times bigger than our cells, a million times bigger than bacteria, and 10 million times bigger than your average virus
Hope this helps <3
The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
