bio 10 Flashcards

Question

cell wall

Answer 1

only in plants, it helps provide strength and support for the cell

Answer 2

* Store water which results in turgor pressure * Much larger in plant cells than in animal cells

Answer 3

* Responsible for regulating the movement of matter into or out of the cell * Separates the cell contents from the outside environment. * The currently accepted model for the structure of the cell membrane is the fluid mosaic model.

Answer 4

* The cell membrane is selective in the type of molecules it allows to pass through – semipermeable membrane. * In general, the passage of materials through the cell membrane is determined by: – Size of the molecules – Charge of the molecule – Solubility of the molecule in lipid 1. Passive Transport Mechanism – Diffusion – Osmosis – Facilitated diffusion 2. Active Transport Mechanism – Pumps – Endocytosis – Exocytosis

Answer 5

Concentration of solutes is higher outside the cell than the concentration of solutes inside the cell. (H2O moves out of the cell causing cell to shrink) (Hyper = more)

Answer 6

Concentration of solutes is lower outside the cell than the concentration of solutes inside the cell. (H2O flows into the cell)

Answer 7

Concentration of solute outside the cell is equal to the concentration inside the cell so there is no net movement of water. Equal H2O in and out Iso = same

Answer 8

* Create pores or channels through which small water-soluble particles are able to move through * The size of the channel determines which particles can pass through * The concentration gradient determines the rate of transport

Answer 9

* Are specific for the molecule that is to be transported. * The molecule is picked up on one side of the membrane and transported to the other side where it is released. * The change in the shape of the protein supplies the mechanism to pass the molecule across the membrane.

Answer 10

 Surface Area of a cube: SA = 6s2

Answer 11

sa=2x(lw+lh+hw)

Answer 12

 A greater number of smaller cells are more efficient than one big cell because they have a large surface area to volume ratio

Answer 13

 To maximize efficiency and promote survival, each individual cell needs to have the greatest possible surface area in relation to volume.  The larger the SA:Vol ratio, the better the cell functions  Large organisms are multi-cellular to maximize potential/survival.

Answer 14

Movement of material across a cell membrane without energy

Answer 15

Process by which molecules move from areas of HIGH concentration to areas of LOW concentration (down the concentration gradient)

Answer 16

How fast or slow solutes diffuse

Answer 17

* The diffusion of water molecules through a selectively permeable membrane * To predict the direction of water movement, solute concentrations inside and outside of the cell need to be compared.

Answer 18

Energy requiring process that enables materials to move across a cell membrane against a concentration gradient.

Answer 19

Movement of large molecules in a membrane bound sac across the membrane * 2 types: * Endocytosis * Exocytosis

Answer 20

the process of taking material into the cell by pockets in the cell membrane

Answer 21

process by which large particles are removed from the cell

Answer 22

Often used to push ions against a concentration gradient by using a protein assisted by ATP

Answer 23

 Upper and lower epidermal cells are tightly interlocked to prevent physical damage or penetration by pathogens (disease)  1 layer thick! Waxy cuticle acts as water barrier to conserve water

Answer 24

 Guard cells on lower epidermis control opening and closing of stomata  allows gas exchange between external and interior photosynthetic cells, also conserve water

Answer 25

 Forms a series of tubes that transport fluids  Look like leaf veins  XYLEM – carries water and mineral from roots to leaves  PHLOEM – carries sugars produced by leaves to other parts of the plant  Arranged together in a vascular bundle

Answer 26

carries water and mineral from roots to leaves

Answer 27

carries sugars produced by leaves

Answer 28

 Efficient for Photosynthesis because: – Close to upper layer for max sun exposure – Packed FULL of chloroplasts – Cytoplasm “streams” in circles so chloroplasts take turns near the top  Most photosynthesis occurs here

Answer 29

 Very few chloroplasts  Round with many spaces between them  Gases collect here before being expelled from stomata

Answer 30

 With more complexity, however, more organization is needed. There are successive levels of organization in multicellular organism.

Answer 31

 The most important gas-exchange organ is the leaf.  Carbon dioxide enters the leaf through the stomata where gases can diffuse through the cell membrane of the spongy tissue cells, and once dissolved, used by chloroplasts in photosynthesis. Oxygen then diffuses out of the spongy tissue cells and is released from the leaf through the stomata.  Water, which enters the leaf through the network of xylem, also exits through the stomata as vapor.  Woody plants have lenticels, which are lens- shaped openings perforating the bark and allowing gas exchange between the bark and the living cells.

Answer 32

 As air diffuses out of the stomata, some of the water is lost.  The evaporation of water from leaves is called transpiration.  To keep plant cells from drying out, guard cells can change their shape to cause the stomata to open/close.  When the stomata are open, carbon dioxide can enter the leaf and oxygen and water vapour exit. Therefore, high rates of photosynthesis are possible when the stomata are open.  When the stomata are closed, gas exchange and water exchange are reduced. Less photosynthesis occurs when the stomata are closed.

Answer 33

acquisition of nutrients and water

Answer 34

transport of nutrients and wastes over short and long distances

Answer 35

movement of oxygen and carbon dioxide between organisms and the environment

Answer 36

removal of wastes from cell processes

Answer 37

 Water enters the cells of the root epidermis by osmosis, where the surface area for absorbing water and dissolved minerals from the soil is increased by hundreds of root hairs. Each tiny root hair is an outgrowth of a single epidermal cell. Water continues to diffuse through the root tissue until it reaches the xylem vessels.

Answer 38

 Unlike xylem cells, phloem cells are living, though some of them lack nuclei. They form phloem vessels with porous cell walls, allowing them to transport organic food material, produced in the leaves during photosynthesis, to all parts of the plant.  Phloem consists of sieve tubes and companion cells arranged end-to-end. Sieve plates are perforated sections that separate sieve tubes and companion cells in phloem vessels.

bio 10 Flashcards

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