Amphibia is the class of vertebrates which is considered to be the first to develop lungs. This allowed amphibians to live successfully on land as terrestrial organisms. Ichthyostega was the first primitive amphibians with nostrils and lungs. Amphibians adopted themselves to live on land with developed lungs.
Answer and Explanation:
By the end of the S phase, the cell contains two entire copies of its genetic information. The cell proceeds to G2 phase when the chromosome starts condensing, and structures required for division are formed. A discrete band of microtubules (pre-prophase band) forms around the cytoplasm in a ring where the edge of the phragmosome lay, again marking the plane of cell division. G2 phase ends with the onset of prophase in which the cell’s chromatin condenses into chromosomes.At the end of the G2 phase, the cell undergoes another checkpoint: G2/M checkpoint, upon which, if conditions are appropriate then the cell proceeds to M phase where it divides.
<span>The amino acid numbers and sequence (Primary structure) plus the precise 3-D structure which is determined, in part, by the bonding and interactions of the amino acids. Thus specific binding sites and/or active sites which result will determine the function of that protein.</span>
Answer:
an operational definition
Explanation: