State additional reasons why mitosis matters in both plants and animals.
Plant cells need microtubules to build structures required for mitosis. Name one of these structures.
Free nucleotides are used during the mitotic cell cycle to build both types of nucleic acid: RNA and DNA. Complete sentences A, B, C and D to give information about nucleotides and nucleic acid synthesis. Write the correct term in each blank. A Each nucleotide has three main components: a ........................................ group, a ........................................ (5 carbon) sugar and a nitrogenous organic base. B The nitrogenous organic base of a nucleotide is either a purine or a ........................................ . C In a DNA nucleotide, the sugar is deoxyribose and in an RNA nucleotide the sugar is ........................................ . D The synthesis of RNA from a template strand of DNA is known as ........................................ .
List three main characteristics of viruses.
Virus dimensions are normally quoted in nanometres ($\text{nm}$). Since $P.\ salinus$ is exceptionally large, it has been described as $1\,\mu\text{m}$ long and $0.5\,\mu\text{m}$ wide. Convert the width of $P.\ salinus$ into nanometres.