Answer:
2. Hip bones
Explanation:
More than 40 million years ago, whales had ancestors who walked on land. Even now, they have a feature they inherited from them - hip bones. Scientists used to think that they are vestigial, i.e. that they lost their function. However, recently they discovered that these bones help whales (and other marine mammals who have them, such as dolphins) maneuver better mating.
Whales developed the rest of the listed features later, when they became marine animals. This is why they are incorrect.
Sodium, potassium, chloride and calcium ions are important for establishing the resting potential of the cell. The sodium-potassium gradient is maintained by a pump which transports 2 potassium inside the cell and 3 sodium ions outside the cell.
Answer:
about 525 billion sperm cells
Explanation:
In fact, the average male will produce roughly 525 billion sperm cells over a lifetime and shed at least one billion of them per month. A healthy adult male can release between 40 million and 1.2 billion sperm cells in a single ejaculation.
Answer:
selective permeability
Explanation:
The property or characteristic of cellular membrane to allow certain substances to pass through the cell is known as selective permeability. The movement of molecules and ions across the cell can be active or passive.
Marshall Nirenberg and Heinrich Mattaeis contributed to out current understanding of the genetic code by discovering genetic codons. Their experiment deciphered the first of the 64 triplet codons in the genetic code by using nucleic acid homopolymer to translate specific amino acids. Their experiment cracked the first codon of the genetic code and showed that RNA controlled the production of certain types of proteins.<span />
