12. Plant Anatomy and Plant Physiology

I. Choose the correct answer.

1. Casparian strips are present in the ______ of the root.

(a) cortex         (b) pith
(c) pericycle    (d) endodermis.

2. The endarch condition is the characteristic feature of:

(a) root            (b) stem
(c) leaves         (d) flower

3. The xylem and phloem arranged side by side on same radius is called ______.

(a) radial          (b) amphivasal
(c) conjoint     (d) none of these.

4. Which is formed during anaerobic respiration?

(a) Carbohydrate         (b) Ethyl alcohol
(c) Acetyl CoA           (d) Pyruvate.

5. Kreb’s cycle takes place in:

(a) chloroplast
(b) mitochondrial matrix
(c) stomata
(d) inner mitochondrial membrane

6. ­­Oxygen is produced at what point during photosynthesis?

(a) when ATP is converted to ADP
(b) when CO2 is fixed
(c) when H2O is splitted
(d) All of these.

II. Fill in the blanks

1. Cortex lies between Epidermis and endodermis.

2. Xylem and phloem occur on the same radius constitute a vascular bundle called Conjoint.

3. Glycolysis takes place in The cytoplasm of the cell.

4. The source of O2 liberated in photosynthesis is Byproduct.

5. Mitochondria is ATP factory of the cells.

III. State whether the statements are true or false. Correct the false statement

1. Phloem tissue is involved in the transport of water in a plant.

Answer:           False.
Correct Statement: Phloem tissue is involved in the transport of food in plants.

2. The waxy protective covering of a plant is called cuticle.
       Answer:    True.

3. In monocot, stem cambium is present in between xylem and phloem.
     Answer:      False.
Correct Statement: In monocot stem, the cambium is absent in between xylem and phloem.

4. Palisade parenchyma cells occur below the upper epidermis in dicot root.
     Answer:      False.
Correct Statement: Palisade parenchyma cells occur below the upper epidermis in dicot leaf.

5. Mesophyll contains chlorophyll.
     Answer:      True.

6. Anaerobic respiration produces more ATP than aerobic respiration.
     Answer:      True.

IV. Match the following

1. Amphicribal

(c) Fern

2. Cambium

(d) Secondary growth

3. Amphivasal

(a) Dracaena

4. Xylem

(e) Conduction of water

5. Phloem

(b) Translocation of food

V. Answer in a Sentence

1. What is the collateral vascular bundle?

When xylem lies towards the centre and phloem lies towards the periphery, it is called the collateral vascular bundle.

2. Where does the carbon that is used in photosynthesis come from?

Carbondioxide present in atmosphere.

3. What is the common step in the aerobic and anaerobic pathway?

Glycolysis is the common step in the aerobic and anaerobic pathway.

4. Name the phenomenon by which carbohydrates are oxidized to release ethyl alcohol.

Fermentation (Anaerobic respiration)

VI. Short Answer Questions

1. Give an account on a vascular bundle of dicot stem.

The vascular bundles of dicot stem are:

  • Conjoint: Xylem and phloem lie on the same radius.
  • Collateral: Xylem lies towards the centre and phloem lies towards the periphery.
  • Endarch: Protoxylem lies towards the centre and metaxylem lies towards the periphery.
  • Open: The cambium is present in between xylem and phloem.

The vascular bundles are arranged in the form of a ring around the pith.

2. Write a short note on mesophyll.

The tissue present between the upper and lower epidermis in leaf is called mesophyll. It is differentiated into palisade and spongy parenchyma.

3. Draw and label the structure of oxysomes.


4. Name the three basic tissues system in flowering plants.

The three basic tissue system in flowering plants are:

  1. Dermal or Epidermal tissue system
  2. Ground tissue system
  3. Vascular tissue system

5. What is photosynthesis and wherein a cell does it occur?

Photosynthesis is a process in which the green plants use sunlight and the green pigment chlorophyll, to synthesize, nutrients from carbon dioxide from air and water. The photosynthesis occurs in green parts of the plant such as leaves, stems and floral buds.

6. What is respiratory quotient?

The ratio of volume of carbon dioxide liberated and the volume of oxygen consumed, during respiration is called Respiratory Quotient (R.Q)

7. Why should the light dependent reaction occur before the light independent reaction?

During light dependent reaction photosynthesis pigment absorb the light energy and convert it into chemical energy ATP and NADPH2.
During light independent CO2 is reduced into carbohydrates with the help of ATP and NADPH2 produced during light dependent reaction.

8. Write the reaction for photosynthesis.

VII. Long Answer Questions

1. Differentiate the following
(a) Monocot root and Dicot root
(b) Aerobic and Anaerobic respiration.

(a) Monocot root and Dicot root

Dicot Root

Monocot Root

1. The Xylem is Tetrarch

1. The Xylem is Polyarch.

2. The conjunctive tissue is made up of parenchyma cells.

2. The conjunctive tissue is made up of sclerenchyma cells.

3. The young root contains a path, but in the old root, pith is absent.

3. Pith cells are made of parenchyma cells with intercellular spaces and contain abundant starch grains.

4. Cambium is present during secondary growth.

4. Cambium is absent.

5. Secondary growth is present.

5. Secondary growth is absent.

(b) Aerobic and Anaerobic respiration

Aerobic

Anaerobic

1. Occur in the presence of oxygen.

1. Occurs, when oxygen is absent.

2. Carbon dioxide, water and ATP are produced.

2. Lactic acid, Ethanol and ATP are produced.

3. It consists of 3 steps:

  • Glycolysis
  • Kreb’s cycle
  • Electron transport chain

3. It consists of 2 steps:

  • Glycolysis
  • Fermentation
    (Ethyl alcohol or Lactic acid are produced)

2. Describe and name three stages of cellular respiration that aerobic organisms use to obtain energy from glucose.

The three stages of Aerobic respiration are:
(i) Glycolysis (Glucose splitting): It is the breakdown of one molecule of glucose into two molecules of pyruvic acid. Glycolysis takes place in the cytoplasm of the cell. It is the first step of both aerobic and anaerobic respiration.

(ii) Krebs Cycle: This cycle occurs in the mitochondria matrix. At the end of glycolysis, 2 molecules of pyruvic acid enter into mitochondria. The oxidation of pyruvic acid into CO2 and water takes place through this cycle. It is also called the Tricarboxylic Acid Cycle (TCA).

(iii) Electron Transport Chain: This is accomplished through a system of electron carrier complex called electron transport chain (ETC) located on the inner membrane of the mitochondria. NADH2 and FADH2 molecules formed during glycolysis and Krebs cycle are oxidised to NAD+ and FAD+ to release the energy via electrons. As they move, the electron release energy which is trapped by ADP to synthesis ATP. This is called oxidative phosphorylation. In this O2 gets reduced to water.

3. How does the light – dependent reaction differ from the light – independent reaction? What are the end products and reactants in each? Where does each reaction occur within the chloroplast?

Light – dependent photosynthesis is called Hill reaction or Light reaction. The Light independent reactions are called Biosynthetic phase.

Light-dependent reaction

Light independent reaction

1. It is called Hill reaction or Light reaction.

1. It is called Dark reaction or Biosynthetic pathway or the Calvin cycle.

2. The reaction is carried out in Thylakoid membranes (Grana) of the chloroplast.

2. This reaction is carried out in the stroma of the chloroplast.

3. Photosynthetic pigments absorb the light energy and convert it into chemical energy ATP and NADPH2.

3. CO2 is reduced into carbohydrates with the help of light generated ATP and NADPH2.

4. It is carried out in the presence of light.

4. It is carried out in the absence of light.

In the light – dependent reaction, the chlorophyll absorbs the light energy and convert it into chemical energy ATP and NADPH2. In the light – independent reaction, CO2 is reduced into carbohydrates with the help of light generated ATP and NADPH2. The light – dependent reaction is carried out in the Grana of the chloroplast. The Light independent reaction is carried out in the stroma of the chloroplast.

VIII. Higher Order Thinking Skills(HOTS) Questions

1. The reactions of photosynthesis make up a biochemical pathway.
(A) What are the reactants and products for both light and dark reactions?
(B) Explain how the biochemical pathway of photosynthesis recycles many of its own reactions and identify the recycled reactants.

(a) Light reactions are carried out in the Thylakoid membranes (Grana) of the chloroplast which use water and energy from the Sun to produce NADPH, ATP and Oxygen. The Dark reaction is carried out in the stroma of the chloroplast. It uses NADPH, ATP and CO2 and produces NADP + ADP + P and high energy sugars.

(b) i. The biochemical pathway of photosynthesis which recycles many of its own reactions.


ii) Name of the recycled reactants :

The products of light reaction, ATP and NADPH2, move out from the thylokoid to the stroma. These ATP and NADPH2 are utilized in Calvin cycle to reduce CO2 to carbohydrate. The used up ATP and NADPH2 are converted to ADP and NADP+

Light reaction converts these energy - depleted compounds ADP and NADP+ back to the high energy forms ATP and NADPH.

2. Where do the light-dependent reaction and the Calvin cycle occur in the chloroplast?

Light-dependent reaction takes place in the presence of light energy in thylakoid membranes (grana) of the chloroplast Calvin cycle occurs at the stroma of the chloroplast.