Explain how acidification of cell walls promotes elongation and how unequal auxin distribution causes bending.
Tę umiejętność sprawdza 12 zadań wzorowanych na arkuszach IB z lat 2022–2026.
Two upright oat coleoptiles receive light from the left. A thin impermeable insert is placed just below the tip on opposite sides of P and Q. The diagram records their appearance before and after exposure. (i) Identify the directional response of Q. (ii)…
In darkness, ten similar oat shoot tips are placed on separate agar blocks. A different block is collected after each contact time shown. After its tip is removed, each block is placed on the right half of a freshly cut shoot. All treated shoots remain in…
Outline the response of a young shoot when illumination comes mainly from its left side.
The shoot changes shape under one-sided illumination. Which set of processes can explain the response? I. Polar positioning of auxin-export proteins redistributes auxin. II. Auxin stimulates proton secretion into the wall. III. Wall acidification permits…
(i) Predict a visible difference between shoot meristem-derived cells grown with a growth-promoting auxin concentration and cells grown without it. (ii) State another hormone that interacts with auxin to coordinate shoot growth.
A young shoot bends towards a light source on its left. Which auxin distribution contributes to that response? A. More auxin on the illuminated left side, producing faster growth there B. Equal auxin on both sides, with identical elongation C. More auxin on…
How can auxin contribute to a plant’s growth response? A. By permanently preventing cell-wall expansion B. By preventing responses to directional light C. By making all plant organs grow at an identical rate D. By regulating growth associated with the shoot…
Which explanation is consistent with the treatment’s effect on shoot growth? A. The barrier prevents auxin moving from the tip to elongating cells below B. The barrier increases auxin movement and therefore stops elongation C. Growth is prevented because light…
(a) Describe how auxin produces a shoot’s directional growth response to light. (b) Outline feedback interactions among hormones controlling ovarian and uterine cycles. (c) Explain how the loop of Henle and ADH influence urine concentration.
Growth of a plant cell requires expansion of its wall. Explain how auxin promotes this expansion.
Growth of a plant cell requires expansion of its wall. Explain how auxin promotes this expansion.
Young oat shoots bend towards a lamp positioned on their right. What explains the differential growth? A. Auxin accumulates on the brighter right side and stops mitosis everywhere B. More auxin on the shaded left side promotes greater cell elongation there C.…
Zapisujemy na Twoim urządzeniu to, bez czego serwis nie działa, np. zalogowanie. Plików analitycznych użyjemy tylko za Twoją zgodą. Szczegóły w polityce prywatności.