The most inclusive division of time is the eon, which can be Archean, Proterozoic, Phanerozoic and they are divided into eras (Early/Middle/Late for the Archean and Proterozoic, Paleozoic, Mesozoic and Cenozoic for the Phanerozoic). Therefore, the correct answer is D. eon.
Each body cell contains the same number and kinds of chromosomes for that organism. The chromosomes contain the same number and kinds of genes for that individual.
I’m pretty sure it is Muscle tissue
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 DThe outermost layer of old epidermal cells are sloughed off and replaced every 15 to 30 days. The sebaceous glands secrete sebum which maintains the skin pH between 3 and 5. Bacteria which metabolize sebum live as opportunistic pathogens on the skin and cause skin infections."
