Frog RBCs contain a DNA-bearing nucleus that is visible in the center of the cell. Human RBCs do not possess nucleus along with other cell organelles such as mitochondria, Golgi apparatus and endoplasmic reticulum in order to accommodate greater amount of haemoglobin in the cells. Denucleation of rbcs is an adaptation, Which makes the mammalian red blood cell effective at transporting oxygen/eliminating CO2.
A chemical substance that an organism requires to live. a nutrient that is scarce or cycles slowly through an ecosystem. ensures that nutrients will be circulated throughout the biosphere.
Answer: A
Explanation:
The nucleus provides the instructions for making the proteins (the DNA) and the ribosomes are actually where the proteins are made.
<span>During photosynthesis, plants use carbon dioxide and produce oxygen. During metabolism oxygen is used and carbon dioxide is a product. Humans impact the carbon cycle during the combustion of any type of fossil fuel, which may include oil, coal, or natural gas.</span>