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What are the differences between DNA and RNA?

There are three main differences between DNA and RNA: 1. RNA has the base uracil instead of the base thymine . These bases are very similar and differ by only one chemical group! 2. RNA nucleotides have a ri...
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Answered by Charlotte C. • Biology tutor
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Distinguish between active and passive immunity

Active immunity is due to the over production of antibodies by the organism itself after the body's defence mechanisms have been stimulated by the invasion of foreign micro-organisms. Whereas, passive immuni...
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Answered by Mani R. • Biology tutor
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What is a dominant allele?

An allele that has the same effect on the phenotype whether it is present in homozygous or heterozygous state. Dominant alleles mask the effect of recessive alleles.
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Answered by Mani R. • Biology tutor
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Why are organisms within a species genetically different?

1) Crossing over - in Prophase I of meiosis, non-sister chromatids in the same bivalent (i.e. chromatids on separate chromosomes within a homologous pair) can exchange alleles, creating new combinations. 2) ...
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Answered by Katherine F. • Biology tutor
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What is transcription?

Transcription is the formation of an mRNA molecule from its complementary DNA template. First the enzyme DNA helicase unwinds the double helix, and the hydrogen bonds between complementary bases break. This ...
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Answered by Katherine F. • Biology tutor
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