NIOS TMA ASSIGNMENT BIOLOGY (314) SOLVED PAPER – (2024-25)| SENIOR SECONDARY| ENGLISH MEDIUM
ASSIGNMENT (TMA) - 2024-25
BIOLOGY
(314)
TUTOR MARKED ASSIGNMENT
Max. Marks: 20
Note:
(i) All questions are compulsory. The marks allotted for each question are indicated against each question.
(ii) Write your name enrolment number, AI name, and subject on the top of the first page of the answer sheet.
हिंदी माध्यम: यहां क्लिक करें
1. Answer any one of the following questions in about 40-60 words. 2
(a) Why do
plants not need an Oxygen carrier like the humans in whom Oxygen is carried by
Hemoglobin? (See lesson-12)
Ans:-
Plants do not require oxygen carriers like haemoglobin in humans, mainly
because of their ability to use diffusion for oxygen transport. This method is
efficient for plants because they generally have a large surface area relative
to their volume, allowing gases to diffuse directly into their tissues.
Mechanisms of
oxygen transport in plants:-
(i) Diffusion:
Plants depend on the diffusion of gases through their stomata and intercellular
spaces. Oxygen produced during photosynthesis can easily move through plant
tissues without the need for special transport proteins.
(ii) Role of
haemoglobin: While plants produce haemoglobin-like proteins, such as
leghaemoglobin in legumes, these perform specific functions rather than acting
as general oxygen carriers. For example, leghaemoglobin helps manage oxygen
levels in root nodules where nitrogen fixation occurs. It binds oxygen to
maintain the low free oxygen concentrations needed for the activity of
nitrogenase, an enzyme sensitive to oxygen.
(iii)
Symbiotic haemoglobin: Some plants, particularly legumes, have symbiotic
relationships with nitrogen-fixing bacteria. In these cases, leghaemoglobin is
important for balancing oxygen levels, ensuring that enough oxygen is available
for respiration while preventing excess oxygen from inhibiting nitrogen
fixation.
(iv)
Stress-induced haemoglobin: Plants also make non-symbiotic haemoglobins
that can help in low-oxygen environments by gathering oxygen and supporting
metabolic processes under stress conditions.
Conclusion:
In summary,
plants do not require oxygen carriers such as haemoglobin because they
effectively use diffusion for gas exchange and have special proteins that
manage oxygen levels in specific contexts, such as in symbiotic relationships
with bacteria. This adaptability allows them to thrive without the need for the
complex oxygen transport system found in animals.
(b) Why does
it happen that during hot summer months although you drink lot of water or cold
drinks, you do not urinate much? Explain. (See lesson-14)
Ans:-
During the summer months, many people experience a decrease in urination
despite drinking a lot of water and cold drinks. Several physiological and
environmental factors may be responsible for this phenomenon.
(i) Excessive
sweating: In high temperatures, the body regulates its temperature
primarily through sweating. When you sweat, a lot of fluid is lost, which can
lead to dehydration if not restored enough. Even though you are drinking a lot
of fluid, the body may prioritize retaining fluid over urinating to maintain
hydration levels. This results in less frequent urination as the kidneys
conserve water to prevent dehydration.
(ii)
Concentrated urine: When fluid intake does not keep pace with fluid loss
through sweating, the urine produced becomes more concentrated. This
concentration occurs because the kidneys filter out waste products while
retaining as much water as possible. As a result, despite adequate fluid
intake, if the body is losing more water than it is taking in through sweat,
urine volume may decrease, leading to less frequent urination.
(iii)
Dehydration risk: Dehydration is a significant concern during the summer
months, especially for people who engage in outdoor activities. Symptoms of
dehydration include frequent urination, dry mouth, and fatigue. As the body
becomes dehydrated, it will further reduce urine output as a protective
mechanism to conserve water.
(iv)
Behavioural factors: In addition to physiological responses, behavioural
factors also play a role. If people are outdoors and do not have immediate
access to a toilet, they may avoid drinking as much fluids, leading to a
tendency to hold urine for longer periods of time. This behaviour can increase
the risk of urinary tract infections (UTIs), as bacteria can grow when urine is
not flushed out regularly.
Conclusion:
In summary, a
combination of increased sweating, potential dehydration, and behavioral factors
contribute to decreased urination during the summer months, even when fluid
intake seems adequate. Maintaining hydration by drinking water regularly and
being mindful of fluid loss through sweating may help minimize these effects.
2. Answer any one of the following questions in about
40-60 words. 2
(a)
Conservation and Management of water has become an urgent step to be taken up
by mankind. Write any four methods of such conservation steps. (See lesson-26)
Ans:- Here
are the four main ways to conserve and manage water:-
(i) Rainwater
Harvesting: Rainwater harvesting is a traditional practice that involves
collecting and storing rainwater for future use. It helps recharge groundwater
levels and reduces pressure on freshwater resources. Rainwater harvesting
systems can vary from simple water butts connected to downpipes to complex
systems that collect rainwater from large areas to serve multiple properties.
(ii)
Greywater Recycling Systems: Greywater systems collect water from sources
such as baths, hand basins and showers and reuse it for washing machines,
toilet flushing and outdoor irrigation. This allows maximum use of water
through efficient reuse and reduces freshwater consumption.
(iii)
Efficient Irrigation Technology: Outdoor irrigation uses significant
amounts of water. Smart irrigation controllers can track factors such as
rainfall or temperature and avoid over-watering. Drip irrigation systems
deliver water directly to the roots of plants, reducing waste compared to spray
sprinklers. Efficient irrigation helps maintain beautiful lawns and gardens
while reducing water consumption.
(iv) Water
conservation habits: Individuals can adopt simple habits to reduce water
waste, such as:
(a) Taking
shorter showers instead of baths
(b) Turning off
taps while brushing teeth or shaving
(c) Repairing
leaky taps and pipes promptly
(d) Running
washing machines and dishwashers only with full loads
(e) Using a
bucket instead of a hose to wash the car
By implementing
these water conservation techniques and developing water-efficient habits, we
can significantly reduce freshwater consumption and ensure sustainable water
management. As water scarcity becomes an increasingly global problem, it is
important for individuals, communities, and nations to adopt these practices.
(b) Which of
the following fossils is a connecting link between reptiles and Birds? Briefly
explain. (See Lesson-01)
(i) Eohippus,
(ii)
Archaeopteryx
Ans:- The
fossil that serves as a connecting link between reptiles and birds is
Archaeopteryx.
Explanation:-
Archaeopteryx
exhibits a combination of features of both reptiles and birds, making it an
important transitional species in evolutionary biology.
Reptilian
features:-
(i) Toothed
jaws: Unlike modern birds, Archaeopteryx had teeth in its jaws.
(ii) Long bony
tail: It had a long tail similar to dinosaurs.
(iii)
Skeletal structure: Its skeletal features included a lizard-like body axis
and free caudal vertebrae.
(iv) Clawed
wings: The forelimbs had a typical reptilian structure, ending in claws.
Avian
features:-
(i) Feathers:
Archaeopteryx had feathers, which is a defining feature of birds.
(ii) Modified
limbs: Its forelimbs were modified into wings, while the hind limbs had
structures typical of birds.
(iii) Fusion
of skull bones: The skull showed a pattern of fusion similar to the pattern
found in modern birds.
This unique
combination of traits marks the evolutionary transition from reptiles to birds,
confirming the role of Archaeopteryx as an important link in the evolutionary
chain.
In
contrast, Eohippus, also known as the dawn horse, is not related to the
evolution of birds and mainly represents the early ancestors of modern horses,
lacking the relevant features linking reptiles and birds.
3. Answer any one of the following questions in about
40-60 words. 2
(a) Which of
the following is found in plant cells only? Mitochondria, Endoplasmic
Reticulum, Cell wall and Ribosome (See Lesson-04)
Ans:- In
plant cells, the structure that is found exclusively is the cell wall.
Explanation
of Cell Components:-
(i) Cell wall:
It is a rigid structure composed primarily of cellulose, which provides support
and protection to the plant cell. It is not found in animal cells, making it
unique to plant cells and some prokaryotes and fungi.
(ii)
Mitochondria: These organelles are present in both plant and animal cells.
They are responsible for energy production through cellular respiration.
(iii)
Endoplasmic reticulum (ER): ER is also found in both plant and animal
cells. It plays an important role in the synthesis of proteins and lipids.
(iv)
Ribosomes: Ribosomes are present in all types of cells, including both
plant and animal cells, as they are essential for protein synthesis.
Thus, the
correct answer to your question is that cell wall is found only in plant cells.
(b) Outline
the diagram of the kidney and briefly describe where ultra-filtration occurs in
the kidney and which molecules pass during ultra-filtration.
Ans:- The
primary function of the kidney involves the process of ultrafiltration, which
occurs in a specific part of the nephron. Below is an outline of the structure
of the kidney, focusing on the ultrafiltration process.
Kidney
Diagram:-
The kidney
can be described as follows:-
(i) Outer
cortex: The outer layer of the kidney.
(ii) Inner
medulla: Contains the renal pyramids and is involved in urine
concentration.
(iii) Renal
pelvis: Funnel-shaped structure that collects urine.
(iv) Nephron: Functional
units of the kidney, including:
(a) Bowman's
capsule: A cup-like sac that surrounds the glomerulus.
(b)
Glomerulus: A network of capillaries where filtration occurs.
(c) Proximal
convoluted tubule: Reabsorbs water, ions and nutrients.
(d) Loop of
Henle: Concentrates urine.
(e) Distal
convoluted tubule: Further adjusts the composition of urine.
(f)
Collecting duct: Collects urine from multiple nephrons.
Ultrafiltration
process:-
(i) Site of
ultrafiltration: Ultrafiltration occurs in the glomerulus, a network of
capillaries located within the Bowman's capsule of the nephron. The structure
of the glomerulus, with its porous capillary walls, facilitates the filtration
process.
(ii)
Mechanism of ultrafiltration:
(a) Blood enters
the glomerulus through the afferent arteriole and exits through the efferent
arteriole. The afferent arteriole has a wider lumen than the efferent one,
which creates hydrostatic pressure that drives the filtration process.
(b) High
hydrostatic pressure pushes small molecules and water from the blood through
the capillary walls into Bowman's capsule, resulting in a fluid called
glomerular filtrate.
(iii)
Molecules passing during ultrafiltration:
During
ultrafiltration, the following types of molecules pass through glomerular
capillaries:-
(a) Water
(b) Glucose
(c) Amino acids
(d) Ions (e.g.,
sodium, potassium)
(e) Urea
(f) Creatinine
Larger
molecules such as proteins and blood cells usually remain in the bloodstream
because of their size and the selective permeability of the glomerular
membrane.
4. Answer any one of the following questions in about
100-150 words. 4
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