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All questions of Class 10 NCERT Biology for UPSC CSE Exam
Largest gland in the body is –- a)Liver
- b)Pancreas
- c)Gastric gland
- d)Adrenal
Correct answer is 'A'. Can you explain this answer?
Largest gland in the body is –
a)
Liver
b)
Pancreas
c)
Gastric gland
d)
Adrenal
 | Pooja Shah answered |
Liver is the largest gland in human body. It carries out many functions such as secretion of bile juices for decomposition of lipids and vitamins, preparation of proteins for blood plasma that enables blood clotting and also detoxification.
Which of the following is biodegradable?- a)Plastic mugs
- b)Leather belts
- c)Silver foil
- d)Iron nails
Correct answer is option 'B'. Can you explain this answer?
Which of the following is biodegradable?
a)
Plastic mugs
b)
Leather belts
c)
Silver foil
d)
Iron nails
 | Raghav Bansal answered |
Leather belts are biodegradable whereas silver foils, plastic mugs and iron nails are non - biodegradable. It takes leather between 25-50 years to completely decompose.
A human zygote has :-- a)46 chromosomes
- b)23 chromosomes
- c)47 chromosomes
- d)48 chromosome
Correct answer is option 'A'. Can you explain this answer?
A human zygote has :-
a)
46 chromosomes
b)
23 chromosomes
c)
47 chromosomes
d)
48 chromosome
 | Anoushka Nambiar answered |
The cells from each parent that combine to form the zygote are called gametes. In humans, the male gamete is called sperm, and the female gamete is called an egg. When the gametes join they form a cell called a zygote. Human sperm and eggs contain 23 chromosomes. Human zygotes contain 46 chromosomes.
Flow of energy in an ecosystem is always- a)unidirectional
- b)bidirectional
- c)multidirectional
- d)no specific direction
Correct answer is option 'A'. Can you explain this answer?
Flow of energy in an ecosystem is always
a)
unidirectional
b)
bidirectional
c)
multidirectional
d)
no specific direction
| | Aishwarya jain answered |
Energy flows only in one direction in an ecosystem.
Depletion of ozone is mainly due to- a)chlorofluorocarbon compounds
- b)carbon monoxide
- c)methane
- d)pesticides
Correct answer is option 'A'. Can you explain this answer?
Depletion of ozone is mainly due to
a)
chlorofluorocarbon compounds
b)
carbon monoxide
c)
methane
d)
pesticides
 | Rahul tiwari answered |
Depletion of ozone layer is mainly due to chlorofluorocarbon compounds.
Practice Quiz or MCQ (Multiple Choice Questions) with Solutions of Chapter "Respiration (Life Processes)" are available for CBSE Class 10 Science and have been compiled as per the syllabus of CBSE Class 10 Science Q. Vocal cards occur in –- a)Pharynx
- b)Larynx
- c)Glottis
- d)Bronchial tube
Correct answer is option 'B'. Can you explain this answer?
Practice Quiz or MCQ (Multiple Choice Questions) with Solutions of Chapter "Respiration (Life Processes)" are available for CBSE Class 10 Science and have been compiled as per the syllabus of CBSE Class 10 Science
Q. Vocal cards occur in –
a)
Pharynx
b)
Larynx
c)
Glottis
d)
Bronchial tube
 | Praveen Yaduvanshi answered |
Ans B bcoz The vocal folds, also known commonly as vocal cords or voice reeds,They vibrate, modulating the flow of air being expelled from the lungs during phonation.
How many forms of fossil fuels are there- a)One
- b)Two
- c)Three
- d)Four
Correct answer is option 'C'. Can you explain this answer?
How many forms of fossil fuels are there
a)
One
b)
Two
c)
Three
d)
Four
 | Shubham Mukherjee answered |
There are three major forms of fossil fuels they are coal, oil and natural gas. They formed from organic remains of plants and animals that were converted into coal, oil and natural gas by exposure to heat and the pressure of the earth’s crust over millions of years.
The minimum speed of wind which is required to run a windmill is:- a)15Km/h
- b)35 Km/h
- c)25Km/h
- d)5 Km/h
Correct answer is option 'A'. Can you explain this answer?
The minimum speed of wind which is required to run a windmill is:
a)
15Km/h
b)
35 Km/h
c)
25Km/h
d)
5 Km/h
 | Krishna Iyer answered |
The minimum wind velocity for a windmill to function is 15 km per hour.
As soon as the speed of the wind becomes less than 15 kilometre per hour, the generator stops working.
As soon as the speed of the wind becomes less than 15 kilometre per hour, the generator stops working.
Which of the following groups does not contain only biodegradable items ?- a)Grass, flowers and leather
- b)Grass, wood and plastic
- c)Fruit-peels, cake and lime juice
- d)Cake, wood and grass
Correct answer is option 'B'. Can you explain this answer?
Which of the following groups does not contain only biodegradable items ?
a)
Grass, flowers and leather
b)
Grass, wood and plastic
c)
Fruit-peels, cake and lime juice
d)
Cake, wood and grass
 | Amit Kumar answered |
Correct Answer :- b
Explanation : A Non-Biodegradable material can be defined as a kind of substance which cannot be broken down by natural organisms and acts as a source of pollution. ... Non-biodegradable wastes are those who cannot be decomposed or dissolved by natural agents.
Plastic is a non-biodegradable substance.
Asexual reproduction is good because it:- a)Involves two parents
- b)Is simple and fast
- c)Shows no variation
- d)Produces defect in offspring
Correct answer is option 'B'. Can you explain this answer?
Asexual reproduction is good because it:
a)
Involves two parents
b)
Is simple and fast
c)
Shows no variation
d)
Produces defect in offspring
| | Anjana Khatri answered |
Asexual reproduction occurs when an organism makes more of itself without exchanging genetic information with another organism through sex.In sexually reproducing organisms, the genomes of two parents are combined to create offspring with unique genetic profiles. This is beneficial to the population because genetically diverse populations have a higher chance of withstanding survival challenges such as disease and environmental changes.
Asexually reproducing organisms can suffer a dangerous lack of diversity – but they can also reproduce faster than sexually reproducing organisms, and a single individual can found a new population without the need for a mate.
Can you explain the answer of this question below:Haemoglobin is –
- A:
Vitamin
- B:
Skin pigment
- C:
Blood carrier
- D:
Respiratory pigment
The answer is D.
Haemoglobin is –
Vitamin
Skin pigment
Blood carrier
Respiratory pigment
| | Krishna Iyer answered |
the hemoglobin increases the oxygen carrying capacity of blood. In humans and most other vertebrates, the most common respiratory pigment is a protein called hemoglobin.
Can you explain the answer of this question below:Digestion of proteins starts in:
- A:
Mouth
- B:
Stomach
- C:
Pancreas
- D:
Small intestine
The answer is b.
Digestion of proteins starts in:
Mouth
Stomach
Pancreas
Small intestine
| | Krishna Iyer answered |
Digestion of proteins starts in stomach and is completed in intestine. The pepsin is the most important proteolytic enzyme present in stomach. It is secreted in inactive pepsinogen form which is activated on exposure to gastric acid. Pepsin breaks proteins into smaller proteoses and peptones. The peptones, proteoses are acted upon by trypsin, chymotrypsin and carboxypeptidase present in pancreatic juice. The action of these enzymes breaks peptones and proteoses into dipeptides. In intestinal juice is present aminopeptidase which finally release amino acids from dipeptides, thus finishing the digestion of proteins.
Which of the following limits the number of trophic levels in a food chain ?- a)Decrease in energy at higher levels
- b)Deficient food supply
- c)Polluted air
- d)Water
Correct answer is option 'A'. Can you explain this answer?
Which of the following limits the number of trophic levels in a food chain ?
a)
Decrease in energy at higher levels
b)
Deficient food supply
c)
Polluted air
d)
Water
| | Ananya Das answered |
Due to the 10% rule, there is a decrease in energy at every higher trophic level.
Which of the following is not a biotic component of an ecosystem ?- a)Rainfall
- b)Plants
- c)Animals
- d)Human beings
Correct answer is option 'A'. Can you explain this answer?
Which of the following is not a biotic component of an ecosystem ?
a)
Rainfall
b)
Plants
c)
Animals
d)
Human beings
| | Amit Kumar answered |
Rainfall is not a living organism
Which of the following is motile?- a)Male gamete
- b)Female gamete
- c)Cotyledons
- d)Zygote
Correct answer is option 'A'. Can you explain this answer?
Which of the following is motile?
a)
Male gamete
b)
Female gamete
c)
Cotyledons
d)
Zygote
| | Krishna Iyer answered |
Sperm motility is the ability of sperm to move efficiently. This is important in fertility because sperm need to move through the woman's reproductive tract to reach and fertilize her egg.
Which of the following is non-biodegradable?- a)Wool
- b)Nylon
- c)Animal bones
- d)Tea leaves
Correct answer is option 'B'. Can you explain this answer?
Which of the following is non-biodegradable?
a)
Wool
b)
Nylon
c)
Animal bones
d)
Tea leaves
 | Srishti Singh answered |
Nylon plastic is the name for a long-chain, fiber forming polyamides, composing one of the largest groups of synthetic polymers. These chains are naturally very resistant to wear and tear, temperature and chemicals.so its non biodegradable.
Which is not a function of the male reproductive system in humans?- a)Nourishing the embryo
- b)Producing the male gametes
- c)Delivering the male gametes to the site of fertilization
- d)Secreting male sex hormones
Correct answer is option 'A'. Can you explain this answer?
Which is not a function of the male reproductive system in humans?
a)
Nourishing the embryo
b)
Producing the male gametes
c)
Delivering the male gametes to the site of fertilization
d)
Secreting male sex hormones
 | Harshu answered |
Nourishing the embryo is the process in female reproductive system in which the embryo is nourished and protected. While the others r male reproductive system. Hope uh got that :)
Which one does not produce any digestive enzyme?- a)Pancreas
- b) Liver
- c)Stomach
- d)none of these
Correct answer is option 'B'. Can you explain this answer?
Which one does not produce any digestive enzyme?
a)
Pancreas
b)
Liver
c)
Stomach
d)
none of these
| | Krishna Iyer answered |
The liver doesn't secrete any enzymes. The liver secretes bile. In the presence of bile, lipase, an enzyme breaks down the fat into smaller units. Bile is stored on the gall bladder.
- a)Large intestine
- b)Mouth
- c)Anal sphincters
- d)Urethra
Correct answer is 'C'. Can you explain this answer?
| | Anita Menon answered |
An anal sphincter is a group of muscles at the end of the rectum that surrounds the anus and controls the release of stool, thereby maintaining continence. There are two sphincter muscles: one is internal and one is external. The external muscle helps maintain continence and keep stool in the rectum.
During digestion, fats are broken down to:- a)Micelles
- b)Fatty acids and glycerol
- c)Amino acids
- d)Glucose
Correct answer is option 'B'. Can you explain this answer?
During digestion, fats are broken down to:
a)
Micelles
b)
Fatty acids and glycerol
c)
Amino acids
d)
Glucose
| | Himaja Ammu answered |
During digestion fats r broken down to fatty acids and glycerol by the process of emulsification....
The main constituent of biogas is : - a)methane
- b)carbon dioxide
- c)hydrogen
- d)hydrogen sulphide
Correct answer is option 'A'. Can you explain this answer?
The main constituent of biogas is :
a)
methane
b)
carbon dioxide
c)
hydrogen
d)
hydrogen sulphide
 | Aditi Choudhury answered |
Bio-gas is an excellent fuel as it contains up to 75% methane. It burns without smoke, leaves no residue like ash in wood, charcoal and coal burning. Its heating capacity is high. Bio-gas is also used for lighting.
The importance of reproduction in organisms is because of :-- a)Formation of new individuals
- b)Production of individuals with same traits
- c)Production of individuals with different traits so as to being varieties in a population
- d)All of the above
Correct answer is option 'D'. Can you explain this answer?
The importance of reproduction in organisms is because of :-
a)
Formation of new individuals
b)
Production of individuals with same traits
c)
Production of individuals with different traits so as to being varieties in a population
d)
All of the above
 | Akshara Basu answered |
Reproduction is an important characteristic feature of living organisms. It is an essential life process which not only helps in survival but also helps in continuity of that race and group immortality, as by reproduction. Young ones replace the old and dying ones. These young ones feed, grow and reproduce again.
Can you explain the answer of this question below:The muscles of the digestive tract contract and relax to allow food to move in downward direction. This process is called ________.
- A:
Swallowing
- B:
Peristalsis
- C:
Digestion
- D:
Assimilation
The answer is b.
The muscles of the digestive tract contract and relax to allow food to move in downward direction. This process is called ________.
Swallowing
Peristalsis
Digestion
Assimilation
 | Pranavi Joshi answered |
Typical movement of the esophagus, stomach, and intestine are called peristalsis. The action of peristalsis looks like an ocean wave moving through the muscle
Which of the following are environmental-friendly practices ?- a)Carrying the cloth bags to put purchases in while shopping
- b)Switching off unnecessary lights
- c)Walking to school instead of getting your mother to drop you on her scooter
- d)All of the above
Correct answer is option 'D'. Can you explain this answer?
Which of the following are environmental-friendly practices ?
a)
Carrying the cloth bags to put purchases in while shopping
b)
Switching off unnecessary lights
c)
Walking to school instead of getting your mother to drop you on her scooter
d)
All of the above
| | Ananya Das answered |
All the practices mentioned are environment friendly
Epiglottis guards the opening of :-- a)Oesophagus
- b)Eustachian tubes
- c)Larynx
- d)Internal nares
Correct answer is option 'C'. Can you explain this answer?
Epiglottis guards the opening of :-
a)
Oesophagus
b)
Eustachian tubes
c)
Larynx
d)
Internal nares
| | Sonam malhotra answered |
The epiglottis is a flexible flap at the superior end of the larynx in the throat. It acts as a switch between the larynx and the esophagus to permit air to enter the airway to the lungs and food to pass into the gastrointestinal tract. The epiglottis also protects the body from choking on food that would normally obstruct the airway.
Copulation in human beings may result in fertilisation during (normal menstrual cycle is for 28 days)- a)4th day and 10th day
- b)21th day and 28th day
- c)11th day and 21st day
- d)any day between 1st day and 28th day
Correct answer is option 'C'. Can you explain this answer?
Copulation in human beings may result in fertilisation during (normal menstrual cycle is for 28 days)
a)
4th day and 10th day
b)
21th day and 28th day
c)
11th day and 21st day
d)
any day between 1st day and 28th day
| | Amit Sharma answered |
Because fertilization of egg starts in 11 to 21 th days after that the unfertilized egg will ready to come out due to which copulation results in fertilization between 11 to 21 th days.
In hydroelectricity power:- a)Kinetic energy is transferred to potential
- b)Potential energy is transferred to kinetic
- c)Solar energy is transferred to wind energy
- d)Wind energy is transferred to solar energy
Correct answer is option 'B'. Can you explain this answer?
In hydroelectricity power:
a)
Kinetic energy is transferred to potential
b)
Potential energy is transferred to kinetic
c)
Solar energy is transferred to wind energy
d)
Wind energy is transferred to solar energy
| | Shubham Mukherjee answered |
Hydroelectricity power stations use the kinetic energy in moving water. But the water comes from behind a dam built across a river valley. The water high up behind the dam contains potential energy.
Human beings are more genetically advanced than monkey because of:- a)Fragmentation
- b)Reproduction
- c)Budding
- d)Variation
Correct answer is option 'D'. Can you explain this answer?
Human beings are more genetically advanced than monkey because of:
a)
Fragmentation
b)
Reproduction
c)
Budding
d)
Variation
| | Rajiv Gupta answered |
Human variability refers to the fact that there is a range of possible values for each of the numerous physical and mental characteristics of human beings. Fundamental Characteristic. Variation is, in fact, inherent in every living species.
The thick and spongy uterine wall breaks when:- a)Embryo starts developing in uterus
- b)The egg is not fertilized by sperm
- c)Fertilization of egg and sperm occurs
- d)The egg is not released by ovary
Correct answer is option 'B'. Can you explain this answer?
The thick and spongy uterine wall breaks when:
a)
Embryo starts developing in uterus
b)
The egg is not fertilized by sperm
c)
Fertilization of egg and sperm occurs
d)
The egg is not released by ovary
| | Anjana Khatri answered |
During your menstrual cycle, hormones make the eggs in your ovaries mature — when an egg is mature, that means it's ready to be fertilized by a sperm cell. These hormones also make the lining of your uterus thick and spongy. ... If pregnancy doesn't happen, your body doesn't need the thick lining in your uterus.
Who introduced the idea of a spontaneous generation ?- a)Aristotle
- b)Empedocles
- c)Anaximus
- d)Aristotle
Correct answer is option 'A'. Can you explain this answer?
Who introduced the idea of a spontaneous generation ?
a)
Aristotle
b)
Empedocles
c)
Anaximus
d)
Aristotle
| | Krishna Iyer answered |
The doctrine of spontaneous generation was coherently synthesized by Aristotle, who compiled and expanded the work of earlier natural philosophers and the various ancient explanations for the appearance of organisms, and was taken as scientific fact for two millennia.
In male reproductive system, the passage of sperms is through:- a)Scrotum
- b)Seminal vesicles
- c)Urinary bladder
- d)Urethra
Correct answer is option 'D'. Can you explain this answer?
In male reproductive system, the passage of sperms is through:
a)
Scrotum
b)
Seminal vesicles
c)
Urinary bladder
d)
Urethra
 | Vikas Kumar answered |
The key male reproductive organs include the testes, epididymis, urethra, vas deferens, prostate gland, seminal vesicle, and penis. The testes are composed of coiled structures called seminiferous tubules, which are the sites of sperm production. Here, the vas deferens joins with the seminal vesicle to form the ejaculatory duct, which passes through the prostate and empties into the urethra. When ejaculation occurs, rhythmic muscle movements propel the sperm forward. Semen, also known as seminal fluid, is an organic fluid that may contain spermatozoa.M
Trophic level in an ecosystem represents- a)oxygen level
- b)water level
- c)energy level
- d)salt level
Correct answer is option 'C'. Can you explain this answer?
Trophic level in an ecosystem represents
a)
oxygen level
b)
water level
c)
energy level
d)
salt level
| | Amit Sharma answered |
- Organisms occupy a place in the natural surroundings or in a community according to their feeding relationship with other organisms.
- Based on the source of their nutrition or food, organisms occupy a specific place in the food chain that is known as their trophic level.
- Producers belong to the first trophic level, herbivores (primary consumer) to the second and carnivores (secondary consumer) to the third.
- The amount of energy decreases at successive trophic levels
Hence, trophic levels represent energy level as well.
Which of the following is a bile pigment?- a)Homopectin
- b)Lignin
- c)Bilirubin
- d)Pectin
Correct answer is 'C'. Can you explain this answer?
Which of the following is a bile pigment?
a)
Homopectin
b)
Lignin
c)
Bilirubin
d)
Pectin
 | Neha Patel answered |
Bilirubin, a brownish yellow pigment of bile, secreted by the liver in vertebrates, which gives to solid waste products (feces) their characteristic colour. It is produced in bone marrow cells and in the liver as the end product of red-blood-cell (hemoglobin) breakdown. The amount of bilirubin manufactured relates directly to the quantity of blood cells destroyed. About 0.5 to 2 grams are produced daily. It has no known function and can be toxic to the fetal brain.
Which of the following is a disadvantage of most of the renewable energy sources?- a)Highly polluting
- b)High waste disposal cost
- c)Unreliable supply
- d)High running cost
Correct answer is option 'C'. Can you explain this answer?
Which of the following is a disadvantage of most of the renewable energy sources?
a)
Highly polluting
b)
High waste disposal cost
c)
Unreliable supply
d)
High running cost
 | Hrishikesh Choudhary answered |
Renewable energy often relies on the weather for its sources of power. Hydro generators need rain to fill dams and thereby provide electricity. Wind turbines need wind to turn the blades. Solar collectors need clear skies and sunshine.
Inter neuron junction where neurotransmitters are released- a)cell body
- b)axon
- c)dendrite
- d)synapse
Correct answer is option 'D'. Can you explain this answer?
Inter neuron junction where neurotransmitters are released
a)
cell body
b)
axon
c)
dendrite
d)
synapse
| | Krishna Iyer answered |
Neuromuscular junctions are between axon ending and muscles and junction between axon ending of one neuron and dendrites of another neuron is termed synapse.
The following light which is more effective in opening of stomata :- a)Green
- b)Red
- c)Blue
- d)(B) and (C) both
Correct answer is option 'D'. Can you explain this answer?
The following light which is more effective in opening of stomata :
a)
Green
b)
Red
c)
Blue
d)
(B) and (C) both
| | Anjana Khatri answered |
Among external factors, light plays predominant role in the movement of guard cells. Blue and red light are effective in both photosynthesis and stomatal opening. However, blue light is found to be more effective (relative to red light) in causing stomatal opening than in photosynthesis.
Oxygen is carried by :-- a)Leucocytes
- b)Erythrocytes
- c)Platelets
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
Oxygen is carried by :-
a)
Leucocytes
b)
Erythrocytes
c)
Platelets
d)
None of these
| | Pooja Shah answered |
The oxygen carried by the erythrocytes can diffuse into the plasma and then through the capillary walls to reach the cells, whereas some of the carbon dioxide produced by the cells as a waste product diffuses into the capillaries to be picked up by the erythrocytes.
Fuel used in thermal power plants is : - a) Water
- b)Uranium
- c)Biomass
- d)Fossil fuels
Correct answer is option 'D'. Can you explain this answer?
Fuel used in thermal power plants is :
a)
Water
b)
Uranium
c)
Biomass
d)
Fossil fuels
| | Hitakshi 💞💞 answered |
Thermal power plants use fossil fuels like coal to produce electricity. These fossil fuels are burnt in power plants in huge amount to heat the water and by producing steam, the turbine runs which results in production of electricity. Water cannot be used as a fuel. Uranium is radioactive in nature. It is used in nuclear power plants. Biomass is used as a fuel but in biomass powered plants. So, the correct answer is option 'D'.
Can you explain the answer of this question below:The maximum affinity of haemoglobin is with –
- A:
Carbon monoxide
- B:
Carbondioxide
- C:
Oxygen
- D:
Ammonia
The answer is A.
The maximum affinity of haemoglobin is with –
Carbon monoxide
Carbondioxide
Oxygen
Ammonia
| | Naina Sharma answered |
Hemoglobin in humans has a very high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Carbon monoxide is thus problematic for humans because it has affinity higher than that of oxygen.
Fallopian tubes of female reproductive system are analogous to which part of the male reproductive system:- a)Scrotum
- b)Vas Deferens
- c)Prostrate gland
- d)Testes
Correct answer is option 'B'. Can you explain this answer?
Fallopian tubes of female reproductive system are analogous to which part of the male reproductive system:
a)
Scrotum
b)
Vas Deferens
c)
Prostrate gland
d)
Testes
| | Arun Yadav answered |
In female reproductive system function of the fallopian tubules is to carry the ovum released by the ovaries. In the same way, In male reproductive system, function of the Vas Deferens is to carry the sperms.
Which of the following can reproduce through regeneration ?- a)Hydra
- b)Planaria
- c)Wall lizard
- d)Both (A) and (B)
Correct answer is option 'D'. Can you explain this answer?
Which of the following can reproduce through regeneration ?
a)
Hydra
b)
Planaria
c)
Wall lizard
d)
Both (A) and (B)
| | Akshara Basu answered |
In asexual reproduction, the planarian detaches its tail end and each half regrows the lost parts by regeneration, allowing neoblasts (adult stem cells) to divide and differentiate, thus resulting in two worms. and hydra is reproduce by budding.
Puberty age in girls is between :-- a)12–18 years of age
- b)10–16 years of age
- c)14–20 years of age
- d)15–18 years of age
Correct answer is option 'B'. Can you explain this answer?
Puberty age in girls is between :-
a)
12–18 years of age
b)
10–16 years of age
c)
14–20 years of age
d)
15–18 years of age
| | Poorvi.m. Singh answered |
Option b is correct because girls attain sexual mechurity and the menstrual cycle /menarch start in this phase,,due to adolescence
Which enzyme is responsible for digesting proteins in the stomach?- a)Ptyalin
- b)Pepsin
- c)Trypsin
- d)HCl
Correct answer is 'B'. Can you explain this answer?
Which enzyme is responsible for digesting proteins in the stomach?
a)
Ptyalin
b)
Pepsin
c)
Trypsin
d)
HCl
 | Palak Patel answered |
Protein digestion begins in the stomach with the action of an enzyme called pepsin. Pepsin is the active protein-digesting enzyme of the stomach
Which of the following is not associated with growth of plant?- a)Auxin
- b)Gibberellins
- c)Cytokinins
- d)Abscisic acid
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not associated with growth of plant?
a)
Auxin
b)
Gibberellins
c)
Cytokinins
d)
Abscisic acid
| | Ananya Das answered |
Abscisic acid is generally associated with inhibiting growth, inducing dormancy, and helping the plant to withstand stress conditions such as drought. It is often referred to as a stress hormone or a growth inhibitor in plants, rather than a promoter of growth. On the other hand, auxins, gibberellins, and cytokinins are hormones that promote various aspects of plant growth and development.
Choose the incorrect statement- a)Bio-mass is a renewable source of energy
- b)The main ingredient of bio-gas is ethane and it gives a lot of smoke and also produces a lot of residual ash.
- c)We are encouraged to plant more trees so as to ensure clean environment and also provide bio-mass fuel
- d)Gobar-gas is produced when crops, vegetable wastes, etc., decompose in the absence of oxygen
Correct answer is option 'B'. Can you explain this answer?
Choose the incorrect statement
a)
Bio-mass is a renewable source of energy
b)
The main ingredient of bio-gas is ethane and it gives a lot of smoke and also produces a lot of residual ash.
c)
We are encouraged to plant more trees so as to ensure clean environment and also provide bio-mass fuel
d)
Gobar-gas is produced when crops, vegetable wastes, etc., decompose in the absence of oxygen
 | Arnab Unni answered |
The main ingredient of biogas is methane. Except option (b), all other options are correct.
Which of the following acts as both endocrine and exocrine glands?- a)Adrenal
- b)Pituitary
- c)Ovaries
- d)Pancreas
Correct answer is option 'D'. Can you explain this answer?
Which of the following acts as both endocrine and exocrine glands?
a)
Adrenal
b)
Pituitary
c)
Ovaries
d)
Pancreas
| | Ananya Das answered |
Pancreas are both exocrine and endocrine glands ; they are exocrine glands because they secrete products - pancreatic juice and endocrine because they secrete other substances directly into the blood stream.
In an ecosystem, herbivores represent- a)producers
- b)primary consumers
- c)secondary consumers
- d)decomposers
Correct answer is option 'B'. Can you explain this answer?
In an ecosystem, herbivores represent
a)
producers
b)
primary consumers
c)
secondary consumers
d)
decomposers
| | Amit Sharma answered |
A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another.
(i) At the base of the food chain lie the primary producers. The primary producers are autotrophs and are most often photosynthetic organisms such as plants, algae, or cyanobacteria.
(ii) Primary consumers are the organisms that eat the primary producers. They are usually herbivores, plant-eaters, though they may be algae eaters or bacteria eaters.
(iii) Secondary consumers are the organisms that eat the primary consumers. They are generally meat-eaters called carnivores.
(iv) Tertiary consumers are the organisms that eat the secondary consumers. These are carnivore-eating carnivores, like eagles or big fish.
Which among the following is not a renewable source of energy ?- a)Solar energy
- b)Biomass energy
- c)Hydro-power
- d)Geothermal energy
Correct answer is option 'B'. Can you explain this answer?
Which among the following is not a renewable source of energy ?
a)
Solar energy
b)
Biomass energy
c)
Hydro-power
d)
Geothermal energy
| | Amit Sharma answered |
Coal is a non-renewable energy source because it takes millions of years to form.
In aquatic plant – Hydrilla stomata are :- a)Present on leaves
- b)Present on stem
- c)Present on roots
- d)Absent
Correct answer is option 'D'. Can you explain this answer?
In aquatic plant – Hydrilla stomata are :
a)
Present on leaves
b)
Present on stem
c)
Present on roots
d)
Absent
| | Arun Yadav answered |
In Hydrilla, the function of stomata is the same as in the case of terrestrial plants i.e. transpiration and exchange of gases like CO2 or O2 but the only thing is that stomata are present more on the upper surface of the floating leaves of the plants as compared to the lower side of the leaves is submerged in water.
By studying the ratio of different isotopes of same element in a material we can know the age of- a)Living animals
- b)Fossil
- c)Both (a) and (b)
- d)Living plants
Correct answer is option 'B'. Can you explain this answer?
By studying the ratio of different isotopes of same element in a material we can know the age of
a)
Living animals
b)
Fossil
c)
Both (a) and (b)
d)
Living plants
| | Rahul Kapoor answered |
There are two ways by which we can determine the age of fossils-
(1) If we dig into the earth and start finding fossils, it is reasonable to suppose that the fossils we find closer to the surface are more recent than the fossils we find in deeper layers.
(2) By detecting the ratios of different isotopes of the same element in the fossil material.This method is known as carbon dating.
Carbon dating is a method to estimate the age of carbon containing materials like trees. Carbon (C) has three naturally occurring isotopes. Both C-12 and C-13 are stable, but C-14 decay to nitrogen-14 with a half-life of approximately 5,730 years. Animals and plants naturally incorporate both the C-12 and C-14 during their lifetimes. When a creature dies, it ceases to consume more radiocarbon while the C-14 already in its body continues to decay back into nitrogen. With the help of C-12 to C-14 ratio, we can estimate the age of dead plants/ animals.
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