Inhaling through the nose
67 million years ago in the form of phyollths (small sllica flecks in grass that make it difficult to digest)
Answer:
See explanation:
Explanation:
Humans are the same, one side to the other. The human body is a mirror image, one side to the other. The cnidarian phylum does not necessarily have bilateral symmetry. Body forms like jelly fish, sea anemones, and coral are examples of cnidarians. Note that jelly fish may be somewhat symmetric, but not totally and not in the same way that the human body is.
Answer:
Is it true that all cells have the same genes, but different genes are active in different cells.
No, all cells are made up of a gene which is inherited from the parents cell. The gene is located in the DNA which is found in the nucleus of every living cell
Explanation:
<h2>Given statement is false</h2>
Explanation:
According to dispersive model of DNA replication,DNA molecules are hybrids of parental and daughter DNA;In this model each individual strand is a combination of original and new DNA
Meselson and Stahl did an experiment on DNA replication using E.coli bacteria
- E.coli was grown in a medium containing heavy isotope of nitrogen,bacteria took up the nitrogen and used to synthesize new biological molecules,including DNA
- It was grown for many generations,the nitrogenous bases of the bacteria's DNA were all labelled with heavy nitrogen
- Bacteria were then switched to light nitrogen isotope and allowed to grow for several generations
- They then measured the density of the DNA using density gradient centrifugation
- This method separates molecules such as DNA into bands by spinning them at high speeds in the presence of another molecule, such as cesium chloride
- Each DNA produced two DNA molecules each with one new strand and one old strand called semi conservative replication(half of the parental DNA conserved in daughter DNA)
- Each DNA strand act as a template for synthesis of new strand
- Hence,dispersive model of DNA was eliminated and semi-conservative model of DNA replication was proved by the above experiment