Chapter 11

Question 1

Osmosis

Answer 1

net diffusion of water molecules across partially permeable membrane from solution of high Ψ to one with low Ψ

Question 2

Partially permeable membrane

Answer 2

membrane that’s permeable to some substances but not to others

Question 3

Water potential (Ψ)

Answer 3

measure of ability of water molecules to move into a solution. Pure water has the highest Ψ.

Question 4

Turgid

Answer 4

description of plant cell with high internal pressure so cytoplasm pushes against the cell wall

Question 5

Flaccid

Answer 5

condition of plant cell where internal pressure is lost and cytoplasm doesn’t push against the cell wall

Question 6

Plasmolysis

Answer 6

plant cell that has lost water by osmosis, cell contents shrinks and cell membrane and cytoplasm pull away from cell wall

Question 7

Turgor

Answer 7

condition of plant when cells are turgid

Question 8

Wilt

Answer 8

changes in plant when it loses too much water, leaves droop and collapse

Question 9

Root hairs

Answer 9

specialised cells on surface of root, take up water and mineral ions from soil

Question 10

Transpiration

Answer 10

loss of water vapour from leaves of plants

Question 11

Transpiration stream

Answer 11

passage of water and mineral ions through roots, stem and leaves

Question 12

Lumen

Answer 12

space in middle of tube such as artery or xylem

Question 13

Lignin

Answer 13

woody material present in some cell walls, strengthens and makes cell impermeable to water

Question 14

Sieve plate

Answer 14

specialised end wall of sieve tube, holes allow connection of cell to next cell

Question 15

Sieve tube

Answer 15

cell found in phloem, consists of tube to transport photosynthesis products

Question 16

Companion cells

Answer 16

specialised cell lying next to sieve tube controlling its activities

Question 17

Vascular bundles

Answer 17

xylem and phloem grouped together in stem or root