9.3 - ibbriner

9.3 - Growth in plants

DCS Topic Code	Statement	Guidance
9.3.U1	Undifferentiated cells in the meristems of plants allow indeterminate growth.
9.3.U2	Mitosis and cell division in the shoot apex provide cells needed for extension of the stem and development of leaves.
9.3.U3	Plant hormones control growth in the shoot apex.	Auxin is the only named hormone that is expected.
9.3.U4	Plant shoots respond to the environment by tropisms.
9.3.U5	Auxin efflux pumps can set up concentration gradients of auxin in plant tissue.
9.3.U6	Auxin influences cell growth rates by changing the pattern of gene expression.
9.3.A1	Micropropagation of plants using tissue from the shoot apex, nutrient agar gels and growth hormones.
9.3.A2	Use of micropropagation for rapid bulking up of new varieties, production of virus-free strains of existing varieties and propagation of orchids and other rare species.