Hereditary retinoblastoma is an autosomal dominant hereditary cancer. Cells from retinal tumors in a child who has this disease
possess________.A. evidence of non-disjunction in all autosomes.B. one non-functional copy of the retinoblastoma gene.C. two non-functional copies of the retinoblastoma gene.D. trisomy for the retinblastoma gene.E. a dominant mutation in the retinoblastoma gene.
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation.
Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.
