Answer:
Multicellular organisms are made of more than one cell and are complex organisms.
They are visible to the naked eye.
They possess distinct organs and organ systems.
They are eukaryotes, i.e., they contain membrane-bound structures.
Their cells exhibit division of labor.
Their size increases with the number of cells in an organism
Explanation:
Answer:
A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose.
B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells.
C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.
Answer:
The statement suggests ability of existing DNA molecule to replicate itself by the process of DNA replication. Each strand of double helical DNA can serve as template for the synthesis of new complementary DNA strand.
Explanation:
Watson and Crick proposed the double-helical structure of DNA. Accordingly, the DNA molecule is a double helical structure in which two polynucleotide chains are held together by base pairing between the complementary bases of two chains.
There are four nitrogenous bases present in DNA: adenine and guanine (purines) and cytosine and thymine (pyrimidines). Adenine always pairs with thymine and cytosine pairs with guanine base.
According to Watson and Crick, the ability of one DNA strand to base-pair with a complementary DNA strand suggests the existence of the DNA replication process. During DNA replication, each DNA strand should serve as a template to specify the nucleotide sequence of the new DNA strand.
