Search over 10,000 free study notes

Synapses are junctions between nerves. They allow information (impulses) to be transferred from one nerve to the next. The first nerve conducts an electrical impulse across its length, which causes it to ...

Similarities Nucleotides consist of pentose sugar, phosphate and base

Differences RNA: ribose (sugar) single stranded Made in the nucleus but can move outside it U, A, G, C bases

DNA: deoxyr...

Allopatric speciation occurs when populations of a species are separated by a physical barrier - this could be a river for animals that cannot swim, for example. Separation of the populations means that t...

DNA (deoxyribonucleic acid) is a double helix composed of units called nucleotides. Each nucleotide is composed of a single deoxyribose sugar, a phosphate group and one of four nitrogen bases. The 4 bases...

Endocrine organs release their products (usually hormones) directly into the blood. The pancreas contains islets of Langerhans which are made up of alpha and beta cells. Beta cells secrete insulin and alp...