Therefore, whenever a ddNTP is added to a growing DNA strand, it is unable to chemically bind with the next nucleotide in the chain, and the DNA strand stops growing. Figure 3: By adding together information about all of the truncated strands, researchers can determine the nucleotide sequence of the DNA target.
Functions of the Bladder. Temporary store of urine â The bladder is a hollow organ. The walls are very distensible, with a folded internal lining (known as rugae), this allows it to hold up to 600ml. Assists in the expulsion of urine â During voiding, the musculature of the bladder contracts, and the sphincters relax.
Urine leaves the bladder through a tube-like structure called the urethra. The lining of the urethra is epithelium.The wall of the urethra is smooth muscle. Urine flow is controlled by two uretheral sphincters: the internal urethral sphincter and the external urethral sphincter. The internal urethral sphincter is at the start of the urethra. This sphincter is composed of smooth muscle.he lining of the urethra is epithelium. The wall of the urethra is smooth muscle. Urine flow is controlled by two uretheral sphincters: the internal urethral sphincter and the external urethral sphincter. The internal urethral sphincter is at the start of the urethra. This sphincter is composed of smooth muscle.