AHSEC| CLASS 11| BIOLOGY| SOLVED PAPER - 2018| H.S.1ST YEAR
2018
Biology
(Theory)
Times: 3 hours
Full marks: 70
Part - I (Botany)
1. What is Inflorescence? Mention the special types of Inflorescences with example. 1+2=3
Ans: The arrangement of flowers on the axils of
flowers is called inflorescence.
There are two
major types of inflorescences – racemose and cymose.
In racemose type
inflorescences, the main axis continues to grow, with the flowers borne later
in acropetal succession.
In cymose type
inflorescences the main axis ends in a single flower, hence limited in growth.
The flowers are borne in a basipetal order.
2. Define Transpiration. Write its types. 1+2=3
Ans:- Transpiration in plants
Like all living
organisms, plants also need an excretory system to discharge excess water from
their bodies. This process of removing excess water from the plant body is
known as transpiration. This is usually the evaporation of water from the
surface of the leaves.
During the
process of transpiration, water molecules in plant tissues are removed from the
aerial parts of plants. Only a small amount of water absorbed by plants is used
for growth and development. The rest ends up as transpiration.
Types of
transpiration
There are three
types of transpiration in plants:
(i)
Stomatal Transpiration:
It is the
evaporation of water from the stomata of plants. Thus most of the water comes
out of the plants. The water near the surface of the leaves turns into vapor
and evaporates when the stomata are opened.
(ii)
Lenticular Transpiration:
Pulses have
microscopic pores in the bark of branches and twigs. The evaporation of water
from the lentils of plants is known as lenticular transpiration.
Lentils are not
present in all plants. There is least water wastage through pulses.
(iii)
Cutaneous Transpiration:
It is the
evaporation of water from the cuticle of plants. The cuticle is a waxy covering
on the surface of the leaves of plants. About 5-10% of the water from the
leaves is lost through cutaneous transpiration. In dry conditions when the
stomata are closed, more water circulates through the cuticles.
Or
Explain the graphic
representation of Glycolytic process of plant Respiration. 3
Ans: The
word glycolysis is derived from the Greek words, glycos for sugar and lysis for
splitting. The scheme of glycolysis was given by Embden, Meyerh and Parnos and
is known as the EMP pathway.
Glycolysis occurs
in the cytoplasm of the cell. In this process glucose undergoes partial
oxidation to form 2 molecules of pyruvic acid. Glucose and fructose are
phosphorylated by the enzyme hexokinase to give rise to glucose-6-phosphate.
Glucose-6-phosphate then isomerase to produce fructose 6-phosphate. ATP is used
in two steps first to convert glucose to glucose 6 phosphate and second to
convert fructose 6 phosphate to fructose 1, 6, biphosphate. Fructose is broken
down into 1,6-biophosphate dihydroxyacetone phosphate and 3
phosphoglyceraldehyde (PGAL). At one step NADH+H+ is formed from NAD+, this is
when 3-PGAL is converted to 1, 3-biphosphoglycerate is oxidized to PGAL and
converted to BPGA with inorganic phosphate. The conversion of BPGA to
3-phosphoglyceric acid (PGA) is also an energy-producing process. In this phase
also the energy is stored in the form of ATP. Another ATP is synthesized during
the conversion of PEP to pyruvic acid. Pyruvic acid is the major product of
glycolysis.
3. Who discovered the plant cell? 1
Ans:- Robert Hooke.
4. What is stomata?
1
Ans:- Small pores present at the base of the leaf
through which exchange of oxygen and carbon-di-oxide takes place are called
stomata.
5. Why potato is called underground stem? 1
Ans:- It grows underground and it’s stem is always
below ground. It is a stem vegetable.
6. Name four whorls of a complete flower. 2
Ans: Each flower has four chakras. calyx, corolla,
androecium and gynoecium.
Calyx:
Calyx is the outermost coral of the flower and the members are called sepals.
The sepals are green leaf-like and protect the flower at the bud stage. Calyx
can be gamosepalous (sepals United) or polysepalous (sepals free).
Corolla:
Corolla is made up of petals. The petals are usually brightly colored to
attract insects for pollination. The corolla may be gamopetalous or
polypetalous.
7. Write the harmful role of Fungi. 2
Ans:- (i) They cause diseases of important crops like
late blight of potato (Phytophthora infestans), black stem rust of wheat
(Puccinia graminis), brown spot of rice (Helminthosporium oryzae) etc.
(ii) They
inspire. Animal and human diseases, for example, mycosis caused by infection
with Aspergillus, Cercospora and Cryptococcus.
8. Differentiate between simple tissue and complex
tissue. 2
Ans:- Following is the difference between simple tissue
and complex tissue:
Simple Tissue:
(i) Simple tissue contains only one type of tissue, hence it is homogeneous.
(ii) It includes
parenchyma, collenchyma and sclerenchyma.
Complex
Tissue: (i) It is composed of different types of cells, hence
heterogeneous.
(ii) It
consists of xylem and phloem.
9. Draw and label a yeast cell. 2
Ans:-
10. Distinguish between Prokaryotic and Eukaryotic
cells. 2
Ans:- Prokaryotic cells:
(i) Lack a
nuclear membrane
(ii) They have
70S ribosome
Eukaryotic
cells:
(i) Possess a
true nucleus
(ii) They have
80S ribosome
11. What is Hormone? Mention various growth hormones
found in plants. 1+2=3
Ans: Hormones are non-nutritive chemicals that act as
intercellular messengers and are produced in very small amounts.
(i) Auxim, (ii)
Gibberlin, (iii) Cytokynin, (iv) Abbsisic Acid.
12. Describe the different types of Vascular bundles
found in the plants. 3
Ans: The following points highlight the four main types
of vascular bundles.
(i) Radial
Vascular Bundles: In these xylem and phloem are arranged in different
radii/option with each other.
(ii) Joint
Collateral: Xylem and phloem are present in the same radius. Phloem located
on the outer side of the xylem. (open and closed type).
(iii) Joint
bilateral: phloem with outer cambium and cambium and central xylem with
inner cambium / inner phloem on outer and inner side of central xylem.
(iv)
Concentric: One type of vascular bundle surrounded by another.
(Amphicribal-phloem surrounds the xylem and amphivasal (leptocentric)-xylem
surrounds the phloem).
13. Define Mitochondria. Describe the structure and
functions of Mitochondria with diagram.
1+4=5
Ans: Mitochondria (plural mitochondria) are a
membrane-bound organelle found in the cytoplasm of eukaryotic cells. It is the
power house of the cell; It is responsible for cellular respiration and (most)
production of ATP in the cell. Each cell may contain from one to thousands of
mitochondria. Mitochondria also contain extranuclear DNA that encodes many
rRNA, tRNA and proteins.
It is a sausage
on a cylindrical shaped structure. Each mitochondria is a double membrane
structure with an outer membrane and an inner membrane. The inner membrane
forms several types of coverings called crituses.
The functions
of mitochondria depend on the type of cell in which they are present.
(i) The most
important function of mitochondria is to generate energy. Simple molecules of
nutrition are sent to the mitochondria to be processed and to produce charged
molecules. These charged molecules combine with oxygen to form ATP molecules.
This process is known as oxidative phosphorylation.
(ii) Mitochondria
help cells to maintain proper concentration of calcium ions within the cell
compartments.
(iii)
Mitochondria also help in the formation of parts of the blood and hormones like
testosterone and estrogen.
(iv) Mitochondria of liver cells contain enzymes that detoxify ammonia.
Or
What is
five-Kingdom classification? Write the major characters of Five-Kingdom
classification. 1+5=5
Ans:- The
classification of five states was proposed by Whitaker in 1969 by R.H. was done
by. The five kingdoms were formed on the basis of characteristics such as cell
structure, mode of nutrition, source of nutrition and body organization. This
includes Kingdom Monera, Kingdom Protista, Kingdom Fungi, Kingdom Plantae and
Kingdom Animalia.
(i) Kingdom
Monera: It includes prokaryotic cells which do not have organized nucleus and
membrane bound cell organelles. Some monerans are autotrophs and some are heterotrophs.
(ii) Kingdom
Protista: It includes algae, diatoms and protozoa. These are the simplest forms
of unicellular and eukaryotes that exhibit both autotrophic and heterotrophic
modes of nutrition.
(iii) Kingdom
Fungi: These are multicellular, eukaryotic moths. These include mushrooms, Rhizopus
and mucor. Some fungi are symbiotic that form relationships with algae cells.
These symbionts are called lichens.
(iv) Kingdom
Plantae: It includes all those plants which are non-motile, multicellular and
eukaryotic organisms whose cell wall is made up of cellulose.
(v) Kingdom
Animalia: It includes all those animals which are multicellular, eukaryotic
organisms whose cells do not have a cell wall. It shows the diversity of the
species.
14. Describe the major differentiating characters in
between Calvin cycle (C3 plants) and Hatch-Slack pathway (C4 plants)
of photosynthesis. 5
Ans:- C3 Plants: (i) Calvin cycle or C3 cycle occurs
in C3 plants.
(ii) C3 plants
have only one type of chloroplast.
(iii) Kranz is not
an anatomy.
(iv)
Photo-respiration takes place in such plants.
C4 Plants: (i) Hatch and slack or C4 cycle occurs in
C4 plants.
(ii) Two types
of chloroplasts are present in C4 plants. The chloroplasts of mesophyll cells
are small and the chloroplasts of bundle sheath cells are large and lack
grains.
(iii) Kranz's
anatomy.
(iv) Photo respiration does not take place in such plants.
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