External skeleton is the correct answer. Hope this helps out !
Alveolar walls are thin to enable the quick passage of oxygen in and out of the lungs. The lungs works hand-in-hand with the heart and also is responsible in converting blood that's de-oxygenated into an oxygenated blood that is usable by the organ systems of the body. The alveolar walls are also designed to have thin membranes so that it can expand and constrict quickly allowing us to breather properly.
Answer:
Renewable Energy Resources.
Explanation:
Unlike fossil fuels which cannot be recovered when destroyed, these sources of energy can be recovered by a means of recycling . Recycling here reduces solid wastes which is one of the causes of land pollution.
Hydroelectric schemes can only be built in mountain regions where rainfall and rivers are plentiful which involves upset of aquatic ecosystem. This poses a dangerous pollution problem though.
Wind generators and solar panels are not very efficient energy producers. However, future schemes for producing solar energy via solar satellites are promising.
1. Contains their own DNA
2. Contains ribosomes that closely resemble prokaryotic cells
3. Reproduce by fission, and they are independent from cells.
Answer:
The transport protein-hormone complexes of lipid soluble proteins can not cross the filtration membrane of glomerulus.
Explanation:
Steroid hormones are water-insoluble (hydrophobic) in nature. Since blood has watery medium, the plasma, the lipid-soluble hormones travel in blood through transport proteins. The transport protein-hormone complexes are too large to cross the filtration membrane of glomerulus. The impermeability of the filtration membrane of glomerulus for protein-hormone complexes increases the half-life of lipid-soluble proteins.
