TS Inter 1st Year Botany Question Paper May 2016

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TS Inter 1st Year Botany Question Paper May 2016

Time: 3 Hours
Maximum Marks: 60

General Instructions:
Note : Read the following instructions carefully.

1. Answer all the questions of Section ‘A’. Answer any six questions out of eight in Section ‘B’ and answer any two questions out of three in Section – ‘C’.
   
2. In Section ‘A’, questions from Sr. Nos. 1 to 10 are of “Very Short Answer Type”. Each question carries two marks. Every answer may be limited to five lines. Answer all the questions at one place in the same order.
3. In Section ‘B’, questions from Sr. Nos. 11 to 18 are of “Short Answer Type”. Each question carries four marks. Every answer may be limited to 20 lines.
4. In Section ‘C’, questions from Sr. Nos. 19 to 21 are of “Long Answer Type”. Each question carries eight marks. Every answer may be limited to 60 lines.
5. Draw labelled diagrams wherever necessary for questions in Section ‘B’ and C.

Section – A (10 × 2 = 20)

Note : Answer all questions. Each answer may be limited to 5 lines.

Question 1.
What does ICBN stand for ?
Answer:
ICBN stands for ‘International code for Botanical Nomenclature’.

Question 2.
What does the term phycobiont and mycobiont signify ?
Answer:
The algal component of lichen is called phycobiont. The fungal component of lichen is called mycobiont.

Question 3.
Why is Mendel considered as the “Father of Genetics” ?
Answer:
Mendel conducted Hybridization experiments in pea plants and also introduced the laws of inheritance in 1866. Hence, he is considered as the “Father of genetics”.

Question 4.
Differentiate actinomorphic from Zygomorphic flower.
Answer:

Actinomorphic flower	Zygomorphic flower
“A flower that can be cut into two equal halves in any vertical plane”. Ex: Datura	“A flower that can be cut into two equal halves in one vertical plane”. Ex: Bean

Question 5.
What are aggregate fruits ? Give an example.
Answer:
The fruits which develop from multicarpellary, apocarpous ovary called aggregate fruits. Each carpel develops into fruitlet and all these fruitlets aggregate together into a single fruit. Ex : Anona, Naravalia.

Question 6.
Write the floral formula of Solanum plant.
Answer:
Br or Ebr, Ebrl, O, K(5) C(5) A5 G(2).

Question 7.
What does “S” refer in a 70S and 80S ribosome ?
Answer:
In both 70S and 80S ribosomes, “S” refer to Sedimentation coefficient expressed in Svedberg units.

Question 8.
Give one example for each of amino acids, sugars, nucleotides and fatty acids.
Answer:
Amino acids : Glycine, alanine
Sugars : Glucose, ribose.
Nucleotides : Adenylic acid
Fatty acids : Glycerol, Lecithin

Question 9.
An anther has 1200 pollen grains. How many pollen mother cells must have been there to produce them ?
Answer:
300 Pollen mother cells.

Question 10.
Define communities. Who classified plant communities into hydrophytes, mesophytes and xerophytes ?
Answer:
An assemblage of all the populations belonging to different species occurring in an area is called community. Eugen Warming classified plant communities into hydrophytes, Mesophytes and xerophytes.

Section – B (6 × 4 = 24)

Note : Answer any six questions. Each answer may be limited to 20 lines.

Question 11.
Write the role of Fungi in our daily life.
Answer:
Uses :

1. Yeast is used to make bread and beer.
2. Some fungi like Pencillium are the source of antibiotics.
3. Some fungi like Agaricus are edible mushrooms.

Disuses :

1. Some fungi cause rot of orange fruits.
2. Fungi spoils bread
3. Albugo causes white rust diesease on Brassica leaves
4. Puccinia causes rust in wheat

Question 12.
Differentiate between red algae and brown algae.
Answer:

Red algae	Brown algae
1. They belong to class Rhodophyceae.	1. They belong to class Phaeophyceae.
2. Most of them are marine and some are fresh water forms.	2. They live in fresh water, brackish and salt water.
3. Cell wall is made up of cellulose, pectin and polysulphate esters.	3. Cell wall is made up of Cellulose and algin.
4. The thallus is multicellular.	4. The thallus range from simple branched filamentous forms to profusely branched forms.
5. Flagella are absent.	5. Flagella are 2, unequal and lateral.
6. The major pigments are Chlorophyll-a,d, and r-phycoerythrin.	6. The major pigments are Chlorophyll-a, c, carotenoids and fucoxanthin.
7. Food materials are stored the form of Floridian starch.	7. Food materials are stored in the form of mannitol and laminarin.
8. Asexual reproduction occurs by non motile spores.	8. Asexual reproduction occurs by biflagellate zoospores.
9. Sexual reproduction is by non-motile gametes.	9. Sexual reproduction is by motile gametes.
10. E.g : Polysiphonia, Porphyra.	10. E.g : Ectocarpus, laminaria.

Question 13.
Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction ?
Answer:

Asexual	Sexual
1. Single parent is involved	1. Two parents are involved
2. Offsprings are genetically identical to each other and to their parent.	2. Offsprings are not identical to parents.
3. No fertilization occurs	3. Fertilization occurs
4. No gametes are involved	4. Gametes are involved
5. No mixing of hereditary material.	5. Mixing of hereditary material.

In multicellular or colonial forms of algae, moulds and mushrooms, the body may split or break into smaller fragments. Each fragment develops into a mature individual and this process is called fragmentation. In liverworts, specialized vegetative structures are present for reproduction called Gemmae.

In flowering plants, the units of vegetative propagation such as runners, stolons, suckers, offsets, rhizomes, corms stem tubers, bulbs and bulbils are capable of producing new offsprings. These units are called vegetative propagules. In all these plants, no involvement of sex organs takes place so vegetative reproduction is also called asexual reproduction.

Question 14.
Give economic importance of plants belonging Fabaceae.
Answer:

1. Pulses like red gram (Cajanus), black gram (Phaseolus) green gram (Phaseolus aureus), Bengal gram (Cicer arietinum) are rich source of proteins.
2. Pods of Dolichos and Glycine are used as vegetables.
3. Seeds of Pisum and Arachis are edible.
4. Ground nut oil from Arachis seeds and soyabean oil from Glycine max are used in cooking.
5. The oil cake from Arachis is used as fodder.
6. The oil from the seeds of Derris indica is used in making medicines.
7. The seeds of Abrus precatorius are used as Goldsmith’s weight.
8. Seeds of Trigonella are used as condiment and medicine. The leaves are used as vegetable.
9. Sesbania and Tephrosia are used as green manure.
10. Crotalaria and Phaseolus are used as fodder.
11. Fibre from Crotalaria is used in making ropes.
12. Indigofera yields blue dye, which is used in colouring clothes.
13. Wood from pterocarpus is used in making musical instruments.

Question 15.
Give a brief account of the types of chromosomes based on the position of centromere.
Answer:
Basing on the position of the centromere, four types of chromosomes are recognized.

They are

1. Metacentric : Centromere is present in between the two arms of the chromosome. It is ‘V’ shaped and consists of two equal arms.
2. Sub-Metacentric : Centromere is present slightly away from the midpoint of a chromosome. It is ‘L’ shaped and consists of two unequal arms.
3. Acrocentric : Centromere is present at the sub terminal position of the chromosome. It appears ‘J’ shaped and consists of one long arm and one short arm.
4. Telocentric : Centromere is present at the terminal position of the chromosome. It appears ‘I’ shaped and consists of one arm.

Question 16.
Though redundantly described as a resting phase does not really involve rest. Comment.
Answer:
The interphase also called phase of nop apparent division though called the resting phase. It is the time during which the cell is preparing for division by undergoing cell growth and DNA replication. The interphase is divided into three further phases. They are a. G₁ phase, S-phase and G₂ phase.

a. G₁ phase : It corresponds to the interval between mitosis and initiation of DNA replication. In this, the cell is metabolically active and grows continuously.
b. S-phase : DNA replication takes place. The amount of DNA per cell doubles.
c. G₂ phase: Proteinsynthesis continues. Cell organelles increases in number.

Question 17.
State the location and functions of different types of meristems.
Answer:
Based on the position, meristems are classified into three types.
They are

1. Apical meristems : The meristems that are present at the tip of the stem and at the tip of the root are called apical meristems. They help in linear growth of the plant body.
2. Intercalary meristems : The meristems that are present in between mature tissues are known as intercalary meristems. They contribute to the formation of the primary plant body and also involves in internodal length.
3. Lateral meristems : The meristems that occur in the mature regions of roots and shoots peripherally called lateral meristems. They help in increase in thickness of the plant organs, e.g: vascular cambium and Cork cambium.

Question 18.
What measures do you suggest to protect the pollinators ?
Answer:

1. Creating own pollinator-friendly garden using a wide variety of native flowering plants.
2. Reducing the use of pesticides in and around our home.
3. Encouraging local clubs or school groups to build butterfly gardens, bee boards and bee boxes.
4. Supporting agriculture enterprises with pollinator – friendly practices to minimize pesticide use.
5. Encouraging Government agencies t take into account the full economic benefits of wild pollinators when formulating – policies for agriculture and other land uses.
6. To develop techniques for cultivating native pollinator species for cropn pollination.

Section – C (2 × 8 = 16)

Note : Answer any two questions. Each answer may be limited to 60 lines.

Question 19.
Explain how stem is modified variously to perform different functions (write any 6 modifications)
Answer:
Stems are modified in several ways to perform different functions.
They are :
1) Tendrils : Slender, spirally coiled structures which may develop either from auxiliary bud (cucumber) or from terminal bud (grapes) are called tendrils. They help in climbing.

2) Thorns : Buds are modified into woody, straight pointed thorns which protect plants from grazing animals.
Ex : Citrus, Bougain villaea.

3) Phylloclade : In some plants of acid zones, leaves are modified into scales or spines to reduce the rate of transpiration. In such plants, stems are modified into flattened, green structure which carryout photosynthesis. Such stems are called phylloclades.
Ex : In euphorbia stem is cylindrical, in casuarina needle like, and in opuntia – flattened, fleshy green.

4) Bulbils : In some plants, the vegetative buds or floral buds store food materials. At maturity, may detach from the parent plants, develop.adventitious roots, grow as new plants thus help in vegetative reproduction. Ex : Diascoria.

5) Underground stems : In some plants, stem grows into soil, store food materials, show perennation, to resist unfavourable conditions and also help in vegetative reproduction. Such stems are called underground stems.
Ex : Rhizome – Ginger, com – colacacia.

6) Sub aerial stems : In some plants, some part of the stem is underground and some part is aerial. Such stems are called sub aerial stems. In such plants, slender, lateral branches arises from the base of the main axis, grow vertically, arches downwards, produce adventitious roots when touches the ground. When they separates from the parent plant, they develop into new plants they help in vegetative reproduction.
Ex : Stolons – Nerium, Jasmine
Suckers – Chrysanthemum, Mertha.

Question 20.
With a neat labelled diagram describe the parts of a mature embryo sac.
Answer:
Mature angiosperm embryosac shows three parts. They are
1) Egg apparatus
2) Antipodals
3) Central cell

1) Egg Apparatus: Three cells present towards the micropyle of the embryosac together called egg apparatus. Of which, the central, largest one is called egg and two lateral cells are called synergids. Synergids show finger like projections towards the micropyle called filliform apparatus.

2) Antipodals : Three cells present towards the chalazal end of the ovule are called antipodals. They are also referred to as vegetative cells of the embryosac and disintegrates before or after fertilisation.

3) Central cell : It is the largest cell of the embryosac. It is formed by the fusion of two polar nuclei. It is also called secondary nucleus. It shows central vacuole and 2 haploid polarnuclei.

Role of synergies :

1. The filliform apparatus of the synergids absorbs foo materials from the Nu cells and supplies to embryosac.
2. It also secretes some chemicals which direct the growth of the pollen tube towards embryosac.

Question 21.
Describe the internal structure of a Dicot root with a labelled diagram.
Answer:
A thin transverse section of dicot root shows three parts namely
(i) Epidermis
(ii) Cortex and
(iii) Stele.

(i) Epidermis – It is the outer most layers made of thin walled cells. Some cells protrude in the form of unicellular root hairs. So called Epiblema. It protects the inner parts. Root hairs help in absorption of water from the soil.

(ii) Cortex – It consists of several layers of thin walled parenchyma cells with inter cellular spaces. The Innermost layer of cortex is called Endodermis. It comprises a single layer of barrel shaped cells without Intercellular spaces. The tangential as well as the radial walls of Endoderm cells show suberin thickenings called casparian strips. Some cells opposite to protoxylem lack these strips called passage cells. They help in the movement of water and dissolved salts from cortex into xylem.

(iii) Stele : It is the central part, consists of 4 layers.

(a) Pericycle : It is single layered, made of thin walled parenchyma cells, present next to endodermis. It produces lateral roots and become vascular cambium during secondary growth.

(b) Vascular Bundle : Xylem and phloem constitutes vascular Bundle. They are arranged on different radius (in alternate manner) so called Radial vascular Bundle, Xylem is exarch, where protoxylem is towards periphery and metaxylem is towards the center. Xylem is diarch to tetrarch condition. Xylem helps in conduction of water and minerals and phloem helps in conduction of food materials.

(c) Medulla It is absent or small, made of parenchyma cells. When present, it helps in the storage of food and water.

(D) Conjunctive tissue: The parenchyma present between xylem and phloem is called conjunctive tissue which also involves in secondary growth.