NIOS Class 12 Biology Chapter 7 Solution – Shoot System
NIOS Class 12 Biology Solution Chapter 7 Shoot System . NIOS Class 12 Biology Chapter 7 Question Answers Download PDF. NIOS Class 12 Biology Notes.
Board |
NIOS |
Class |
12th (Higher Secondary) |
Subject |
Biology |
Topic |
Question Answer, Solution, Notes |
INTEXT 7.1
1.) Name the part of plant which bears nodes, leaves and flowers.
Ans: Shoot system is an aerial and erect part of plant body which grows upwards ,hence stem bears nodes, leaves and flowers
2.) Lateral branch develops from which bud?
Ans : Lateral branch develops from Axillary bud
3.) Why is it difficult to break lateral roots and not lateral branches on stem?
Ans: It is difficult to break lateral roots and not lateral branches on stem because lateral roots originate from inner layer, that is, pericycle
4.) Roots are negatively phototropic and positively geotropic, what pattern of growth does the stem show?
Ans: Opposite of root ,the stem shows positively phototropic which grows and bends towards light and negatively geotropic which grows away from gravity
INTEXT 7.2
1.) Name the meristematic zone in which cells divide in all planes.
Ans: The cell divides in Corpus of meristematic zone un all the planes
2.) From which meristematic layer does the vascular tissue develops?
Ans : From Procambium the vascular tissue develops.
3.) Which structure gives rise to a lateral branch? Name the type of its origin.
Ans: Lateral Branches arise from axillary buds present in the axil of leaves . Each axillary bud is a small, compact, underdeveloped shoot covered with a large number of overlapping leaf primordial. Internodes of this bud enlarge and develop into a branch. Therefore the development of branches is exogenous
4.) What is the structure known as which covers the apical meristem of root but is absent in stem?
Ans: Root cap covers the apical meristem of root but is absent in stem.
INTEXT 7.3
1.) What are plants with weak stem trailing on the ground known as?
Ans: Creepers are plants with weak stem trailing on the ground .They are weak, unable to stay upright and trail on ground .
2.) Name the modification to which Runner, Stolon, Offset and Sucker belong.
Ans: Runner, Stolon, Offset and Sucker belong to Sub-aerial modification.
3.) What is a phylloclade with one or two internodes called?
Ans:. Cladode is a phylloclade with limited growth i.e., with only one or two internode which help in photosynthesis process.
4.) ‘Haldi’ and onion belong to which category of stem modification respectively?
Ans: Haldi belongs to Rhizome and onion benlongs to Bulb modification.
5.) Match the items of column A with those of column B
Column A | Column B (Ans) |
Tendril | Climbing |
Sucker | Reproduction |
Thorns | Protection |
Bulb | Perennation |
Phylloclade | Photosynthesis |
INTEXT 7.4
1.) Give one primary function of stem.
Ans: (i) Conduct water and minerals Plants and animals from roots to leaves
(ii) Support and position the leaves so that they receive as much sunlight as possible and can exchange gases efficiently during photosynthesis and respiration.
2.) How does sugarcane plant multiply?
Ans: Sugarcane multiply by Stem cutting. Cutting of plants that contain at least one node.
3.) Match the following in column A with column B
Column A | Column B (Ans) |
Opuntia | Photosynthesis |
Duranta | Protection |
Ginger | Perennation |
Potato | Storage of food |
Stem | Conduction |
INTEXT 7.5
1). Differentiate between conjoint and collateral vascular bundle.
Ans: In conjoint xylem and phloem are together in one bundle where as in collateral the xylem and phloem on the same radius with phloem towards the periphery
2.) What is the region between two vascular bundles in a dicot stem known as?
Ans: Medullary ray is the region between two vascular bundles in a dicot stem known as
.3.) Where will you find radially arranged vascular bundles with exarch xylem?
Ans: The radially arranged vascular bundles with exarch xylem is found in Roots
INTEXT 7.6
1.) Name the two lateral meristems which ‘are responsible for increase in birth of stem.
Ans: Cork cambium and vascular cambium are responsible for increase in birth of stem
2.) From which region does the interfascicular cambium develop?
Ans:. The cells of medullary rays adjoining the strip of vascular (Fascicular) cambium become meristematic and form interfascicular cambium
3.) Define bark.
Ans: All the dead cells lying outside the active phellogen constitute the bark.It is the outermost layer of stem and roots.
4.) Why are lenticels, non suberized?
Ans: Woody branches and tree trunks can exchange gas through the lenticels, which are tiny pores, Therefore lenticels are non submerized
5.) The stems of grasses, and rice, remain weak and thin, why?
Ans: monocot plants like wheat, rice, maize, and grasses bend easily due to absence of secondary growth in their stems
6.) Which layers constitute the periderm? What is it’s function?
Ans: Phellem, Phellogen, Phelloderm are the layers constitute the periderm , which have Protective function
INTEXT 7.7
1.) Which type of wood is formed when the cambium is less active?
Ans: summer wood is formed when the cambium is less active in which it forms narrow vessels.
2.) How can you determine the age of a tree?
. Ans: The age of a tree can be determined by counting the annual rings
3.) Why is heart wood commercially more valuable?
Ans: As the plant ages in the central part of stem, the inner cells of sap wood that become non-functional and dark in colour constitute, heart wood. It is commercially more valuable by having properties such as Durable, resistant to attack of pathogen.
- Why does a tall tree stand erect even in strong wind and lashing rain?
Ans: A tall tree stand erect even in strong wind and lashing rain by Presence of abundant mechanical tissue like sclerenchyma and secondary xylem
5.) Define wood.
Ans: Wood is secondary xylem produced by the activity of vascular cambium in dicot stem .It is a tough, fibrous substance found on a tree or shrub’s trunk or branches.
INTEXT 7.8
1.) Define venation.
Ans: Arrangement of veins and veinlets in the lamina is known as Venation. It is of two types (i) Reticulate venation .(ii) Parallel venation
2.) Differentiate between unicostate and multicostate venation.
Ans: Unicostate have Reticulate and parallel venation with one mid rib, giving out secondary veins like in feather and multicostate having many strong veins spreading out from a common point like fingers from palm
3.) What is the type of venation found in peepal and palm leaves?
Ans: Reticulate and parallel are the type of venation found in peepal and palm leaves respectively
4.) Name the structure which arises in the axil of leaf
Ans: Auxillary bud arises in the axil of leaf
5.) What is the prominent vein called which is present in the middle of lamina and runs from base to apex?
Ans: Midrib is present in the middle of lamina and runs from base to apex.
INTEXT 7.9
1.) Name the structure to which the leaflets are attached in a compound leaf.
Ans: leaflets are attached in a compound leaf to the Rachis
- ) What is the structure which helps you differentiate a leaf from a leaflet?
Ans: Presence of axillary bud in leaf but not in leaflet differentiate a leaf from a leaflet
3.) What are the two types of compound leaves known as ?
Ans: Pinnately and palmately are the compound leaf
INTEXT 7.10
1.) What is the type of phyllotaxy found in mango, ‘tulsi’ and guava plants?
Ans: The phyllotaxy in mango is Alternate, in tulsi is opposite-decussate and in guava is opposite-superposed
2.) Match the following items of column A with those of column B
Column A | Column B |
Pitcher | Trapping insect |
Spines | Protection |
Phyllode | Photosynthesis |
Tendril | Climbing |
3.) Give two examples of insectivorous plants.
Ans: Pitcher plant and bladderwort are insectivorous plant
4.) Water chestnut shows two different types of leaves on the same plant, what is such a condition known as?
Ans: In dicot leaves, the mesophyll differentiated into palisade and spongy tissue, while in monocot leaves, it only consists of spongy tissue.
INTEXT 7.11
1.) How is the mesophyll tissue of dicot leaf different from that of monocot leaf? What is it’s function?
Ans: Mesophyll differentiated into palisade and spongy tissue in dicot leaf but composed of only spongy tissue in monocot leaf. It consists of chloroplast, which performs photosynthesis by containing parenchyma (chlorenchyma).
2.) Where are stomata located in a grass leaf?
Ans: Stomata is present in both surfaces of leaf. They are made up of two semi circular guard cells surrounding a pore-stoma
3.) Name the structure through which plants growing in humid areas get rid of excess of water in liquid form.
Ans: Plants growing in humid areas get rid of excess of water in liquid form is Hydathodes .These are specialised structures present in leaves of angiosperms (garden nasturtium) occurring in humid climate
4.) Match the following item of column A with that of column B
Column A | Column B(Ans) |
Bulliform cells | Monocot leaf |
Transfer of Water and Mineral salts | Xyelm |
Stomata only on lower surface | Dicot leaf |
Hydathodes | Guttation |
Hair | Protection |
Exchange of gas | Stomata |
INTEXT 7.12
1.) What is the collection of sepals and petals respectively known as?
Ans: The collection of sepals and petals known as Calyx and Corolla respectively.
2.) Match the following items of column A with those of column B
Column A | Column B(Ans) |
(a) Flower | (v) Modified shoot |
(b) Polycarpellary | (iv) Many carpels |
(c) Petals | (ii) Pollination |
(d) Monodelphous | (i) China rose |
(e) Carpel | (iii) Reproductive organ |
3.) Define placentation.
Ans: It is the manner in which placentae are distributed in the ovary is called placentatio . Placenta is the point of attachment of ovules in the ovary.
4.) Name the type of placentstion where ovary is many chambered and ovules are arranged on the central axis
Ans: Axile
INTEXT 7.13
1.) What is a cyamose inflorescence?
Ans:. Cymose is the main axis terminates in a flower, and there is only limited expansion.
2.) Give one difference between Raceme and Spike.
Ans: The major difference between Raceme and Spike is that racemes have stalked flowers, but spikes have sessile flowers.
3.) Define inflorescence.
Ans: The arrangement of flowers on the floral axis known as the peduncle is known as an inflorescence. Inflorescence could be terminal or axillary
4.) Name the type of inflorescence found in sunflower and Fig.
Ans: Capitulum and Hypanthodium is found in sunflower and Fig
INTEXT 7.14
l.) Define Fruit.
Ans: Fruit is a ripened ovary that develops after fertilization
2.) Give two examples of false fruits.
Ans: Examples of false fruits Apple, pear
3.) What is the fruit wall known as which is formed by the ovary wall?
Ans: In fruits, the ovules develop into seeds and the ovary wall matures into fruit wall which is called pericarp. Pericarp is thick and differentiated into three regions-(a) epicarp t (b) mesocarp, (c) endocarp
4.) Give the names of three layers of pericarp of a fleshy fruit.
Ans: Pericarp is thick and differentiated into three regions-(a) epicarp which forms the skin of the fruit (b) mesocarp, which middle pulpy and (c) endocarp which forms inner hard and stony
5.) Match the following of column A with that of column B
Column A | Column B (Ans.) |
(a) Apple | (v) False Fruit |
(b) Hesperidium | (iv) Oranges |
(c) Mango-edible part | (ii) Mesocarp |
d) Coconut -edible Part | (iii) Endosperm |
(e) Tomato | (i) Berry |
TERMINAL EXERCISE
1.) Differentiate between
(i) Dicot stem and monocot stem – (a) The epidermal hairs in dicot stem is present , while it is absent in monocot stem (b) Vascular bundle in docot stem is very less in numbers, while in monocot dtem it is in larger number.
(ii) Root and stem : (a) In root , the pericycle consist of many layers of sclerenchymatous and parenchymatous cells, while in stem it have only parenchymatous cells.(b) Cuticle is absent in roots, while present in stems
(iii) Racemose and cymose inflorescence : (a) In racemose , main axis have unlimited growth, while cymose have limites growth. (b) Flowers grow in an acropetal pattern in racemose, while cymose have Basipetal flower order
(iv) Stoma and hydathode : (a) Stoma is present throught out the leaf and hydathode is located at vein endings near leaf margin only (b) Stomata open and close depending upon light intensity and hydathode always remain open
(v) True fruit and false fruit : (a) A true fruit is a ripened ovary that develops after fertilization and False fruits are those that develop with additional floral components such the thalamus, receptacle, or calyx as a part of the fruit.
(vi) Dicot and monocot leaf : (a) In dicot leaf stomata generally in lower epidermis while in monocot leaf stomatar generally in lowerand upper epidermis.(a) In dicot leaf Bulliform cells are absent and it is present in upper epidermis.
2.) Explain the different types of underground modified stem?
Ans: Stems are variously transformed into underground, subaerial, and aerial stems for purposes including producing and storing food, perennation, offering mechanical support and protection, and vegetatively multiplying.
There are three types of modification (a)Underground Modified Stems: They are Thick, fleshy, flattened stem under the soil . They have Nodes and internodes, scaly non green leaves and buds eg: Rhizome, corm, bulb etc.
(b) Sub aerial modifications Of stem: As a result of their weakness, stems are prostrate on the ground or may become partially buried in the top soil.eg :runner, stolon, sucker etc
(c) Aerial stem modifications: The entire stem or a portion of it is altered to serve specific purposes.emerge in the leaf’s axil, bear internodes and nodes, and they may also bear leaves, buds, and flowers. Eg :stem tendril, thorns ets.
3.) Explain the process of secondary growth in dicot stem.
Ans: Secondary phloem grows from the vascular cambium in the middle and secondary xylem in the periphery. In the pericycle, the cork cambium (phellogen) also differentiates, giving birth to the secondary cortex (phelloderm) on the interior and cork (phellem) on the periphery.Here , there is formation of secondary tissues due to the activity of vascular cambium and vascular cork.
4.)Draw and label the vertical section of dicot leaf.
5.) Define the following
(a) Flower: the portion of a plant that produces seeds; it consists of reproductive organs (stamens and carpels) that are frequently encircled by a colourful corolla (petals) and a green calyx (sepals).
(b) Actinomorphic: Actinomorphic is a variation of flower that it split into two identical halves along any vertical line
(c) Heterophylly: Heterophylly is the situation where the some plant produces more than one variety of leaf.
(d) Phyllotaxy : It is the configuration of leaves on a stem or branch. The positioning and arrangement of the leaves ensures that they receive sufficient sunlight for photosynthesis.
(e) Hypogynous : Hypogynous is the term in which the ovary is located on the thalamus in the highest position, with the other three whorls successively below it. Apparently, ovary is superior.
(f) Parthenocarpic fruit: It is a fruit that grows without being fertilised. It lacks seeds or contains nonviable seeds.
(g) Venation : Arrangement of veins and veinlets in the lamina is known as Venation. It is of two types (i) Reticulate venation .(ii) Parallel venation
6.) What is cork cambium? State its functions.
Ans: This tissue is known as secondary tissues, and the increase in circumference is known as secondary growth. It is used to produce the protective layer
7 Draw labelled diagrams of the following
(a) Raceme and corymb inflorescence
(b) Axile and parietal placentation
Axile placentation
parietal placentation
8.) What is a fruit? Enlist the various types of simple- fleshy fruits giving one example of each type
Ans: A true fruit is a ripened ovary that develops after fertilization. Ovules develop into seeds and the ovary wall matures into fruit wall which is now called pericarp
(i) Pepo – cucumber, watermelon (ii) Hesperidium – lemon, orange (iii) Pome – apple, pear (iv) Etaerio (cluster) of drupes – Raspberry.
9.) What are the edible parts of the following fruits
(a) Mango : Mesocarp
(b) Orange: Juicy hairs from endocarp
(c) Apple: Fleshy thalamus
(d) Banana : Mesocarp and endocarp
(e) Coconut: Endosperm
(f) Cashew nut : Peduncle and cotyledons
10.) Match the following of column A with that of column B
A | B |
Tendril | Climbing |
Stolon | Reproduction |
Thorn | Protection |
Tuber | Food, storage |
Capitulum | Sunflower |
Phylloclade | Photosynthesis |
11.) Name the type of modification of an underground, non-green structure bearing nodes and internodes and ‘eyes’.
Ans: Rhizome have non-green structure bearing nodes and internodes and ‘eyes’
12.) If a section of stem shows scattered vascular bundles which are closed, have ‘Y’ shaped xylem and are surrounded by bundle sheath; what group of plant is it?
Ans: Monocot stems
13.) What is the region ouside the phellogen known as?
Ans: The region ouside the phellogen known as cork cambium.
14.) When the cambium is less active whic
NIOS Class 12 Biology Solution Chapter 7 Shoot System . NIOS Class 12 Biology Chapter 7 Question Answers Download PDF. NIOS Class 12 Biology Notes.
h type of wood does it produce?
Ans: When the cambium is less active it produce autum wood.
Also See: Next Chapter No. 8 Question Answer