5 A freshly obtained dandelion stem measuring 5cm long was split lengthwise to obtain two similar pieces. The pieces were placed in solutions of different concentrations in petri dishes for 20 minutes. The appearance after 20 minutes is as shown. Epidermis Epidermis Piece in L Piece in La (a) Account for the appearance of the pieces in solutions L, and L.​

Fan egg cell containing the (n+1) number of chromosomes combines with a sperm cell containing the (n) number of chromosomes, what is the result of this union? a) all future somatic cells of the organism will contain the (2n + 1) number of chromosomes. b) all future somatic cells of the organism will contain the (2n - 1) number of chromosomes. c) only certain somatic cells of the organism will contain the (2n + 1) number of chromosomes. d) all future somatic cells of the organism will contain the normal diploid number of chromosomes.

Which of the following is a consequence of urban heat islands? increased precipitation downwind of the city? increased precipitation upwind of the city? decreased winds within the city? increased winds within the city?

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.