Answer:
D fossil record
Explanation:
Depending on what layer of earth the fossil was recorded then they could determine a rough date. Then they would use carbon dating to be more exact.
Answer: Rosalind Franklin
Franklin created an x-ray photograph that allowed Watson and Crick to work out the 3D structure of DNA.
Answer:
Ligand-receptor interaction is the first interaction that triggers cell signalling.
Ligands are the hormones, drugs or neurotransmitters that specifically bind with receptors present in cell surface to initiate cell signalling. Ligand binding to the receptor is reversible. Binding of the ligand to the receptor can activate or inactivate receptor. Activation may lead to cell signalling pathways. Inside cells, there are secondary molecules which on activation starts a cascade of reactions. which in-turn regulate the function of the ligand molecule.
At first, the activated receptor relates with G proteins molecules in the cell.
before the ultimate physiological effect of the ligand on the cell's behavior is produced Therefore, the cellular signaling starts as soon as the first messenger (the ligand) binds to its receptor.
hope this helps
Answer:
B. DR, Dr, Rd, dr
Explanation:
This question involves two genes. Alleles D and R are dominant over alleles d and r. These two genes obey the law of independent assortment as proposed by Gregor Mendel.
Based on the question, a genotype RrDd will produce the following combination of gametes following the process of meiosis:
DR, Dr, dR, dr
