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a.

Root apex	Shoot apex
1. Is sub -terminal in positions	1. Occupies terminal position
2. Is protected by a root cap	2. Is protected by apical bud, young
	leaves & leaf primosdia
3. It has no nodes and internodes	3. It has nodes and internodes
4. It does not bear any appendages.	4. It bears lateral appendages

b. 

(b) There are three types of endosperms in angiosperms :

1.    Nuclear endosperm:- It occurs in polypetalous dicotyledons. First few divisions of primary endosperm nucleus are not followed by cell wall formation, the nuclei thus produced remain free in cytoplasm of embryo sac.

2.    Cellular endosperm - It occurs in gamopetalous dicotyledons. Wall formation commences with first division of primary endosperm nucleus. First wall is usually laid down transversely, but subsequent divisions are irregular.

3.    Helobial endosperm - It occurs in members of order Helobiae. First division of nucleus is followed by formation of transverse wall which divides embryo sac into small chalazal and large micropylar chamber.  Few divisions in chalazal chamber & it degenerates. Free nuclear division in micropylar chamber are followed by wall formation.

(c) (i) Capillary water is the large amount of water that is retained in the minute interstitial spaces in forms of thin films surrounding soil particles. It is the source of almost all the water that plant absorbs from soil.

(ii) Osmosis is the movement of water molecules from the region of low concentration to the region of high concentration through semi permeable membrane. 

(iii) Aeroponics : A system where roots of plant are suspended into air and sprayed with oxygenated nutrient enriched water.

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Dicot leaf	Monocot leaf
Dorsiventral leaf	Isobilateral leaf
Stomata more on the lower surface of the leaf	Stomata equally distributed.
Bulliform cells are present in the epidermis.	Bulliform cells are absent in the epidermis
Mesophyll is not differentiated into palisade and spongy parenchyma	Mesophyll is differentiated into palisade and spongy parenchyma

(b) 

Nitrogen: It is an integral part of amino acids, proteins vitamins, coenzyme, nucleotide, alkaloids and chlorophyll.

Phosphorus : It is a constituent of cell membrane nucleic acids and nucleotide, certain coenzyme and A.T.P influences nitrogen metabolism used in the phosphorylation of sugar in respiration.

Potassium : It helps to maintain the electrical, osmotic and anion/cation balance across cell membranes, assists active transport of certain materials. It also helps in protein synthesis and is a cofactor of enzymes found in photosynthesis and respiration; it is a constituent of sap vacuoles in plants and so help to maintain turgidity.

Sulphur : A constituent of coenzyme A, Ferredoxin, Vitamins and amino acids.

Magnessium : A constituent of chlorophyll molecules; an activator for many enzyme helps in photosynthesis and Carbohydrate metabolism.

Calcium : A major component of the middle lamella of cell walls and it is necessary for their proper development, aid the translocation of carbohydrate and amino acid.

Iron : It is a constituent of electron carriers e.g. cytochoromes needed in respiration and photosynthesis and a constituent of enzymes e.g. dehydrogenase.

Micronutrients:

Chlorine : Helps to maintain the electrical, osmotic and anion/cation balance across cell membranes.

Manganese : It activates enzyme involved in fatty acid synthesis.

Boron : Helps in the mobilization of nutrients, cellular differentiation development.

Zinc : It is involved in biosynthesis of IAA, activates enzymes like carboxylases.

Copper : It is an essential part of plastocyanin.

Molybdenum : Nitrogen fixation & Nitrogen metabolism.

The Essentiality of a mineral element

(1) The element must be absolutely essential for normal growth and development of the plant.

(2) The requirement of the element must be specific and it can not be replaced by another element.

(3) The element must be directly involved in the nutrition of the plant, is the part of structural molecules.

(c)  

Nastic movements	Tropic movements
Nastic responses are also growth movement which occur in response to external stimuli but here the movement is unrelated and the direction of the stimulus is not fixed, it is diffused.	Tropic Response: are the growth movement which occur in response to unidirectional external stimuli and result in positioning of the plant part in the direction of stimulus.
For example geotropism, seismonasty	For example - Geotropism, phototropism.

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Secondary growth in stem—Activity of the Cambium :

1. Formation of Cambium ring : During secondary growth, the cells of medullary rays with the intrafascicular cambium develop meristematic activity and form strips of cambium called interfascicular cambium. The intra and interfascicular cambium unite to form a complete ring called cambial ring or phellogen. The activity of cambial ring gives rise to secondary growth.

2. Formation of secondary tissues : The cambial ring becomes active as a whole and starts cutting off new cells. The cells cut off on the outer side get differentiated into phloem and are called secondary phloem. The cells cut off on the inner side are modified into the elements of xylem which constitute secondary xylem. The secondary phloem consists of sieve tubes, companion cells, phloem fibres and phloem parenchyma. Secondary xylem consists of pitted vessels, tracheids, xylem fibres, xylem parenchyma.

3. Secondary medullary rays : Certain cells of cambium form some narrow bands of living parenchyma cells passing through secondary xylem and secondary phloem and are called secondary medullary rays. These provide radial conduction of food from the phloem and water, mineral salts from xylem.

4.Annual rings : Activity of cambium is not uniform in those plants which grows in the regions where favourable climatic conditions (spring or rainy season) alternate regularly with unfavourable climatic conditions (cold winter or dry hot summer). In temperate climates, cambium becomes more active in spring and forms greater number of vessels with wider cavities, while in winter it becomes less active and forms narrower and smaller vessels. The wood formed in the spring is called spring wood and that formed in dry summer or cold winter, autumn wood. These two woods appear together in the form of a concentric ring, in the transverse section of the trunk and this is known as annual ring. The growth of successive years appears in the form of concentric or annual rings, each annual ring representing the year’s growth.

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Dendrochronology

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(a)
1) Radial Vascular Bundle: In these, the xylem and phloem are arranged in different radii / alternative with each other.

2) Conjoint Collateral: Xylem and phloem are present on the same radius. Phloem located on the outer side of the xylem. (Open and closed types).

3) Conjoint Bicollateral: Phloem and cambium on the outer and inner side of the central xylem / central xylem with outer phloem outer cambium and inner phloem inner cambium.

4) Concentric: One type of vascular bundle surrounded by the other. (Amphicribal– Phloem surrounds xylem and Amphivasal (leptocentric) – xylem surrounds phloem).

Monocot root	Dicot root
Cambium is absent	Cambium appears at the time of secondary growth.
Pith is well developed	Pith is small or absent
Vascular bundles are numerous	Vascular bundles are numerous

c. Effect of light on photosynthesis:
i. High light intensity may become inhibitory as they bring about photo-oxidation/solarisation of chlorophyll. Reduce turgidity and close stomata. 
ii. Different wavelengths influence photosynthesis differently. Green is least effective, blue and red regions are most effective.
iii. Increase in light and intensity up to a certain limit increases the rate of photosynthesis.
iv. Intensity of light affects the rate of photolytic reaction and controls the rate of ATP and NADP production.

Effects of temperature on photosynthesis. 

Temperature:

i. Increase in temperature up to a certain optimum, increases the rate of photosynthesis.

ii. Low temperatures inhibit the rate of photosynthesis by declining CO2 diffusion rates or directly affecting enzymatic action / photosynthesis stops at 40C.

iii. Optimum temperature for photosynthesis ranges between 30 C and 35 C.

iv. High temperature increases transpiration, wilting of leaves / stomatal closure – affects photosynthesis.