Mineralogists group minerals into families based on their chemical composition. ... Most minerals are made up of combinations of chemical elements. In this group a single element like the copper shown here are found in a naturally pure form. Silicates This is the largest group of minerals.
Excretion I believe let me know if i was wrong.
:)
Answer:
PCBs and DDT are chemicals that were banned more than 30 years ago, but our air, water, land, and bodies are so contaminated that decades of cleanup efforts have yet to eliminate their threats to our health. Today, food is one of the most likely exposure routes to PCBs.
Answer: ONLY CERTAIN SUBSTANCES CAN PASS THROUGH IT
Explanation:
1 only gases and water can pass through it.
2 substances need permission to pass through it.
3 only certain substances can pass through it.
4 substances need carrier molecules to pass through it.
5 ATP is always needed to move molecules across the plasma membrane.
3A)Amino acids-peptide
3B)Enzymes–speed up
3C)Active sites–substrate
3D)Unchanged
3E)[follow the instructions given]
4A)DNA—RNA
4B)Nucleotide—Deoxyribose–Phosphate–Nitrogen base
4C)DNA
4D)Thymine–Adenine—Cytosine–Guanine
4E)Hydrogen bonds
