Ch1- Autotrophic nutrition

Question 1

Nutrition

Answer 1

Nutrition is the the scientific study of food and the various modes of nutrition

Question 1

Importance of nutrition

Answer 1

1. Important source of vital processes of the body, as it provides the body with energy
2. Food is needed for growth and the repair of worn out cells

Question 2

Adaptation of root hair to its function

Answer 2

1. Thin wall to permit passage of water
2. Large number to increase SA of water absorption
3. Secretes vicious substance to: Help penetrate the soil- Fix the plant
4. Solution concentration in it is more than that of the soil to help water pass from soil to root hair by osmosis

Question 3

Diffusion

Answer 3

It’s the movement of molecules from high to low conc. due to the continuous free motion of the molecules of diffused substance

Question 4

Osmosis

Answer 4

It’s the diffusion of water from high to low conc. passing through a semi permeable membrane

Question 5

Osmotic pressure

Answer 5

It’s the pressure which causes the diffusion of water from high to low conc. passing through a semi permeable membrane
As concentration of solute inc. osmotic pressure inc.

Question 6

GRF cells act as an osmotic system

Answer 6

Due to the difference in conc. of water between cells which creates osmotic pressure that leads to osmosis from high to low conc. through a semi permeable membrane

Question 7

Imbibition

Answer 7

It’s the ability of the organic solid particles (Colloidal substances) to absorb liquids and increase in volume

Question 8

Hydrophilic compounds such as

Answer 8

Sugar
Cellulose
Protien
Lignin 
Pectin

Question 9

Water passes from root cells to xylem

Answer 9

1) Osmosis: through cell vacuole due to difference in osmotic pressure
2) Plasmodesmata: osmosis from one cortex cell to another
3) Imbibition: through cell walls and intercellular spaces

Question 10

Plasmodesmata

Answer 10

The network of fine cytoplasmic strands connecting the protoplasm of cells together

Question 11

Casparian strip

Answer 11

It’s the endodermal cells on which the lateral walls are covered by SUBERIN
To prevent lateral movement of water and direct water only to xylem
Through Plasmodesmata by osmosis

Question 12

Macro-Nutrients + examples

Answer 12

Elements needed in big quantities
Eg: Calcium
Magnesium
Nitrogen

Question 13

Micro-Nutrients + examples

Answer 13

Elements needed in very small quantities (Trace elements, coenzymes)
Eg: Zinc
Chlorine
Manganese

Question 14

What happens if: Macro or Micro nutrients are absent

Answer 14

It may lead to the stop of plant growth

Question 15

Absorption of minerals takes place by:

Answer 15

Diffusion of ions
Selective Permeablity
Active transport

Question 16

Active transport

Answer 16

It’s the transfer of substances using chemical energy obtained from respiration against concentration gradient

Question 17

Importance of photosynthesis

Answer 17

1. Source of energy: chemical energy stored in food
2. Human Economic: fibers used in textile fabrics as paper and wood, others industries as fats, alcohol, vinegar
3. Fuel source: petroleum, coal, natural gas are from solar energy obtained from plants
4. Source of oxygen: 21% of oxygen in air is a product of photosynthesis

Question 18

Importance of Glucose

Answer 18

1. Broken during respiration to give energy
2. Proteins required for growth are formed
3. Converted to starch to be stored

Question 19

Function of Stroma

Answer 19

Fixes CO2

Question 20

Function of Grana

Answer 20

Absorbs sunlight (Chlorophyll)

Question 21

Adaptation of grana to its function

Answer 21

1. Each disk is hallow from the inside
2. Margin extends to meet margin of the other disk
3. It’s structure increase the SA of chlorophyll exposed to light

Question 22

Pigments that form chlorophyll

Answer 22

Chlorophyll A: Blue Green
Chlorophyll B: Yellow Green - 70%
Xanthophyll: Lemon yellow - 25%
Carotene: Orange Yellow -5%

Question 23

GR Starch is found in small size

Answer 23

Because starch granules change to soluble sugar (sucrose) to be transferred in xylem to other plant organs

Question 24

Function and location of magnesium in chlorophyll

Answer 24

Gives it the ability to absorb light, located in the center of chlorophyll

Question 25

Leaf structure and its adaptation

Answer 25

1. Presence of leaves on stems and branches exposes them to sunlight 2. Lead blade is thin and flattened to receive light 3. Blade is supported by mid rib 4. Upper and lower surface are covered by CUTIN except stomata

Question 26

GR presence of mid rib in leaves

Answer 26

1. To supply leaves with absorbed water from roots | 2. To transport high energy food to different parts of the plant

Question 27

Function of stomata

Answer 27

1. For gas exchange | 2. Controls the rate of water evaporation since it opens at day and closes at night

Question 28

GR Lower surface of the leaf contains more stomata than the upper surface

Answer 28

To be away from direct sunlight, to decrease the loss of water by transpiration

Question 29

Leaf structure and its adaptation

Answer 29

1. Presence of leaves on stems and branches exposes them to sunlight 2. Lead blade is thin and flattened to receive light 3. Blade is supported by mid rib 4. Upper and lower surface are covered by CUTIN except stomata

Question 30

GR presence of mid rib in leaves

Answer 30

1. To supply leaves with absorbed water from roots | 2. To transport high energy food to different parts of the plant

Question 31

Function of stomata

Answer 31

1. For gas exchange | 2. Controls the rate of water evaporation since it opens at day and closes at night

Question 32

GR Lower surface of the leaf contains more stomata than the upper surface

Answer 32

To be away from direct sunlight, to decrease the loss of water by transpiration

Question 33

Tissue between upper and lower Epidermis

Answer 33

Mesophyll

Question 34

Palisade vs Spongy (Shape)

Answer 34

Plaisade: cylindrical, elongated, parenchyma cells perpendicular to the surface with narrow intercellular spaces Spongy: irregularly shaped, loosely arranges parenchyma cells with wide intercellular spaces

Question 35

Palisade Vs Spongy (Content, function)

Answer 35

Palisade: large number of chloroplasts, for absorption of light Spongy: Air chambers, few chloroplasts. Aeration, storage of gases

Question 36

GR Palisade cells are perpendicular to the surface

Answer 36

It facilitates the free movement of the plastids: When the light intensity decreases, they collect near the surface to absorb more ligjt When the light intensity increases, they escape inside to be protected from damage

Question 37

GR: NADPH2 and ATP are energy fixing molecules

Answer 37

Because they are both essential for formation of glucose which is the source of energy for the plant

Question 38

Walls of cells absorb water by Imbibition not osmosis

Answer 38

Because it's made of cellulose which is a colloidal substance that has the ability to absorb water and increase in volume. Osmosis isn't possible because the cell wall is fully permeable not semi permeable

Question 39

Light Reaction Vs Dark reaction (Limiting factor, action of enzymes, location in chloroplast, time of day, products)

Answer 39

Light: - Light - Not enzymatic reactions, but it contains a coenzyme (NADPH2) which carries Hydrogen to stroma - Grana - Day only - Oxygen as a byproduct, NADPH2 Dark: - Temperature - Enzymatic reactions to produce glucose - Stroma - Day and Night - Glucose