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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...

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.

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) ...

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 ...

Phototropins are enzymes found in the plasma membrane of particular cells. They are phosphorylated when hit by blue light. 2) This phosphorylation triggers the movement of auxin across the plant shoot by act...