CLASS 10TH

HIGH YIELD TERMS

CONTAIN MOST IMPORTANT QUESTIONS AND TERMS

DOUBLE CIRCULATION:- for each single cycle, from body to body , the same blood passes twice through heart, first as deoxygenated blood towards right side and then as oxygenated blood towards left side of heart. This is called as double circulation.

POLLINATION

1.      DEFINITION:-The transfer of pollen grains from anther (of stamen) to the stigma (of carpel) is called as pollination.

2.      AGENTS OF POLLINATION:-The common agents responsible for successful pollination are: - wind, water, insects, birds, bats etc.

TYPES OF POLLINATION

SELF-POLLINATION	CROSS POLLINATION
The transfer of pollen grains from anther of a flower to the stigma of the same flower is called as self-pollination.	The transfer of pollen grains from anther of a flower to the stigma of another flower is called as cross pollination.

INTRAUTERINE CONTRACEPTIVE DEVICES (IUCD/IUD)

Q.  If a woman is using a copper- T, will it help in protecting her from sexually transmitted diseases (STD). (NCERT)

Ans:-Copper T do not protect from STD’s because it does not prevent the entry of semen. Thus fluid to fluid contact that takes place in the vagina. Copper T only prevents the implantation of the embryo in the uterus.

DIFFERENCE BETWEEN BINARY FISSION AND MULTIPLE FISSION

	BINARY FISSION	MULTIPLE FISISON
NUMBER OF DIVISIONS	In binary fission, nucleus of parent cell divides only once to form two daughters	In multiple fission, nucleus of parent cell undergoes repeated divisions to form a number of daughter nuclei.
REQUIRED CONDITIONS	Binary fission occurs under favourable conditions.	Multiple fission occurs both under favourable and unfavourable conditions.
KARYOKINESIS	Nucleus of parent cell divides only once to form 2 daughter nuclei.	Nucleus of parent cell divides multiple times to form a number of daughter nuclei.
CYTOKINESIS	In binary fission, cytoplasm undergoes cleavage after each nuclear division.	In multiple fission, cytoplasm does not divide after every nuclear division.
RESIDUE	No part of the parent body is left unused.	A part of parent body (covering and cytoplasm) is left behind as residue.
EXAMPLE	Amoeba, paramecium, Leishnmania	Plasmodium

SSC IN FEMALES

Q. What are the changes seen in girls at the time of puberty? (NCERT)

Ans:-The changes that seen in girls at the time of puberty are:

1.      Increase in subcutaneous fat, broadening of pelvis.

2.      Growth of breasts and external genitalia (vulva)

3.      Growth of pubic hair and extra hair in the armpits.

4.      Initiation of menstruation and ovulation.

ROLE OF SEMINAL VESICLE AND PROSTATE

Q. what is the role of the seminal vesicles and prostate gland. (CBSE 2008. 2009)

Ans:- Along the path of vas deferens, glands like prostate and seminal vesicles add their secretions so that sperms get a fulid medium. This fluid medium makes transport of sperms easier, and move towards the female genital tractl by their tail..

	FUNCTION
SEMINAL VESICLES	SV are pair of lobulated glands. It secrete 60-70% of semen plasma, which is alkaline and viscous in nature. It provides nutrition to sperms. Seminal vesicles contains following components: 1.      Fructose- sugar: - It nourishes the sperms. 2.      Proteins:- for nourishment and stimulation of sperms. 3.      Prostaglandins: - It provides movement to the sperms in female genital tract.
PROSTATE GLAND	PG is single large pyramidal gland. It occurs in the area of the union of urethra with ejaculatory ducts. Secretion of prostate glands is thick, milky and alkaline It secretes 20-30% of semen plasma. It contains chemicals essential for the motility of sperms. It affects the vaginal pH so that sperms move smoothly inside the vagina.

Q. What are the functions performed by the testis in human beings?(NCERT EXERCISE 5)

Ans:-Testes perform the dual function of spermatogenesis and testosterone production:

1.      SPERMATOGENESIS: - It is the production of sperms from germinal cells found in seminiferous tubules.

2.      TESTOSTERONE PRODUCTION: - It is the secretion of testosterone by Leydig’s cells. This hormone brings about secondary sexual character in boys.

How does reproduction help in providing stability to populations of species? (NCERT EXERCISE)

Ans:- Living organisms reproduce for the continuation of a particular species. Reproduction provides stability to populations of a species, by equalizing birth and death ratio.

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

·         Answer

·         Multicellular organisms such as humans possess complex body designs. In multicellular organisms only superficial cells present on surface layer are in direct contact with the environment for diffusion.

·         All other cells and internal organs are not in direct contact with the environment. Also cell to cell diffusion is a very slow process.

·         Thus diffusion is insufficient and multicellular organisms require specilised organs to meet the oxygen requirements.

Q.  Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

Ans: -

·         Birds and mammals are warm blooded animals. Their body temperature does not depend upon environmental temperature.

·         They constantly required oxygen, (for more cellular respiration) to produce energy to maintain their body temperature constant.

·         They maintain a constant body temperature by cooling themselves when they are in a hotter environment & by warming their bodies when they are in a cooler environment.

·         Because these animals require more oxygen (O₂) thus it is necessary to separate oxygenated and deoxygenated blood.

Q. How the amount of urine is produced regulated?

The amount of urine produced depends on following factors:

1.         The amount of excess water and

2.         Blood pressure

3.         Dissolved wastes present in the body.

4.         Habitat of an organism and

5.         Hormone such as Anti-diuretic hormone (ADH).

·         In case of scarcity of water in body,(like in summer) blood pressure decreases, so that nephric filtrate also decreases and becomes concentrated due to less water. At this time, ADH is secreted from pituitary gland, which increases the reabsorption  rate of water into the peritubular capillaries. Thus amount of urine decreases and it becomes concentrated.

·         In case of excess of water in body, (like in winter) blood pressure increases, so that nephric filtrate also increases and becomes dilute due to excess water. At this time, ADH is secreted in very low amount from pituitary gland, which decreases the reabsorption rate of water into the peritubular capillaries. Thus amount of urine increases and it becomes dilute.

What are outside raw materials used for by an organism?

·         Answer

·         Carbon based molecules were the basis for the outside raw materials used by organisms because life on earth depends upon carbon based molecules.

·         The raw materials required by an organism can be quite varied depending on the complexity of the organism and its environment.

·         Autotropes uses inorganic energy like CO₂, water and minerals as outside raw materials.

·         Heterotropes used carbohydrates and oxygen as outside raw materials.

What is the role of the acid in our stomach?

·         Answer

HCl secreted from the parietal (oxyntic) cells of stomach has 4 important function:

1.      HCl converts inactive propepsin(pepsinogen)  into active pepsin.

2.      HCl makes the stomach environment acidic (pH=2.0-2.3) which is essential for the proper function of propepsin.

3.      HCl softens the food the kill the microorganisms in food.

4.      HCl also stops the function of salivary amylase.

What is the function of digestive enzymes?

·         Answer

·         Enzymes are proteins which catalyze the biological reactions and act as molecular scissors.

·         Enzyme causes hydrolytic splitting of complex macro-molecules into simple soluble and diffusible micro-molecules.

·         These simple particles can be easily absorbed by the blood and thus transported to all the cells of the body.

Proteins ----àpeptones------àpeptides-----àamino acid

How is the small intestine designed to absorb digested food?

·         Answer

·         The inner epithelial lining of small intestine possesses numerous finger like projections called as villi, which increases the surface area for efficient absorption of digested food.

·         Villi possess blood capillaries and lymph vessels (lacteals) for quick transport of absorbed food.

·         From the blood stream, the absorbed food is delivered to each and every cell of the body.

Enlarged view of a villus

What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?

·         Answer

·         Aquatic organisms obtain oxygen for respiration from water, which is very low in amount. It is less than 1% oxygen in dissolved state in water.

·         Terrestrial organisms take oxygen directly from the environment, which has a very high concentration of oxygen (up to 21%).

·         Since the amount of oxygen in water is fairly low as compared to the amount of oxygen in the air, thus the rate of breathing in aquatic organisms is much faster than in terrestrial organisms.

DIFFERENCE BETWEEN ARTERIES, VEINS AND CAPILLARIES

ARTERIES	VEINS	CAPILLARIES
Arteries are the distributing blood vessels which carry the blood away from the heart to various organs.	Veins are the collecting blood vessels, which carry the blood towards the heart from various organs.	Capillaries are exchanging blood vessels that is helpful in exchanging glucose and respiratory gases.
Arteries have oxygenated blood except pulmonary artery.	Veins have de-oxygenated blood except pulmonary vein.	Capillaries contain both oxygenated and de-oxygenated blood.
Blood flow rapidly and under pressure in arteries.	Blood flow slowly and with little pressure in veins.	Blood flows with moderate pressure.
Arteries have thick elastic walls because arteries have the bear the high blood pressure.	Veins are thin walled because blood pressure is low in veins	Capillaries are thin walled and one cell thick because they have to exchange nutrition and gases.
Arteries do not have valves because blood flows with jerks in them.	Veins have internal valves to prevent back flow of blood
Lumen of arteries is narrow	Lumen of vein is wide
Arteries are deep seated	Veins are superficial.

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

·         Answer

·         Multicellular organisms such as humans possess complex body designs. In multicellular organisms only superficial cells present on surface layer are in direct contact with the environment for diffusion.

·         All other cells and internal organs are not in direct contact with the environment. Also cell to cell diffusion is a very slow process.

·         Thus diffusion is insufficient and multicellular organisms require specilised organs to meet the oxygen requirements.

:

What criteria do we use to decide whether something is alive?

·         Answer

Any visible movement such as walking, breathing, or growing is generally used to decide whether something is alive or not. However, a living organism can also have movements, which are not visible to the naked eye. Therefore, the presence of life processes is a fundamental criterion that can be used to decide whether something is alive or not.

What are outside raw materials used for by an organism?

·         Answer

·         Carbon based molecules were the basis for the outside raw materials used by organisms because life on earth depends upon carbon based molecules.

·         The raw materials required by an organism can be quite varied depending on the complexity of the organism and its environment.

·         Autotropes uses inorganic energy like CO₂, water and minerals as outside raw materials.

·         Heterotropes used carbohydrates and oxygen as outside raw materials.

What processes would you consider essential for maintaining life?

·         Answer

Life processes such as nutrition, respiration, transportation, excretion, etc. are essential for maintaining life.

What are the differences between autotrophic nutrition and heterotrophic nutrition?

Autotrophic nutrition	Heterotrophic nutrition
That mode of nutrition in which an organism prepare its own organic food from inorganic raw materials like CO2 , water and sunlight.	That mode of nutrition in which an organisms depends directly or indirectly on autotrpes to fulfill its organic needs.
An external source of energy  is required for synthesis of food	External source of energy is not required because the energy is already present in taken up food.
Digestion is absent	Inernal or external digestion is prestnt.
Pigments like chlorophyll is required to trap light energy	Pigments like chlorophyll is not required.
All green plants and some bacteria are autotrophs	All animals and fungi are heterotropes.

Question 2:

Where do plants get each of the raw materials required for photosynthesis?

·         Answer

The following raw materials are required for photosynthesis:

• The raw material CO₂ enters from the atmosphere through stomata.

• Water is absorbed from the soil by the plant roots.

• Sunlight, an important component to manufacture food, is absorbed by the chlorophyll and other green parts of the plants.

What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?

·         Answer

Aquatic organisms obtain oxygen for respiration from water, which is very low in amount. It is less than 1% oxygen in dissolved state in water.

Terrestrial organisms take oxygen directly from the environment, which has a very high concentration of oxygen (up to 21%).

Since the amount of oxygen in water is fairly low as compared to the amount of oxygen in the air, thus the rate of breathing in aquatic organisms is much faster than in terrestrial organisms.

How is oxygen and carbon dioxide transported in human beings?

·         Answer

TRANSPORTATION OF OXYGEN

1.      97% O₂ in combined state with Haemoglobin(Hb) called as oxyhaemoglobin oxyHb.

2.      3%  O₂ is transported with plasma in dissolved state.

TRANSPORTATION OF CO₂

1.      23% CO₂ in combined state with Haemoglobin(Hb) called as carbaminoHaemoblogin.

2.      70% as sodium bicarbonate

3.      7% CO₂ is transported with plasma in dissolved state.

·         What are the different ways in which glucose is oxidized to provide energy in various organisms?  OR

·         What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.

Ans:- Glucose is first broken down in the cell cytoplasm into a three carbon molecule called pyruvate. Pyruvate is further broken down by different ways to provide energy.

·         The breakdown of glucose by different pathways can be illustrated as follows.

·         In yeast and human muscle cells, the breakdown of pyruvate occurs in the absence of oxygen.

·          whereas in mitochondria, the breakdown of pyruvate occurs in the presence of oxygen

PARAMETERS	AEROBIC RESPIRATION	ANAEROBIC RESPIRATION
DEFINITION	It is a common method of respiration in which oxygen is required.	It is a rare method respiration in which oxygen is not required.
BREAKDOWN	Respiratory substrate (i.e. glucose) is completely broken down.	Respiratory substrate (i.e. glucose) is not completely broken down.
OCCURRENCE	It occurs partly in cytoplasm and partly in mitochondria.	It occurs entirely in cytoplasm. Mitochondria is not required.
END-PROUDCTS	End products are inorganic like CO2 and H2O	Atleast one end product must be organic like ethanol or lactic acid.
ENERGY RELEASED	38 ATP (net gain=36 ATP) or 686 K Cal energy is released per mole of glucose.	2 ATP or 36K Cal energy is released per mole of glucose.
ORGANISMS	It occurs in most of the organisms.	It occurs in the roots of some waterlogged plants, some parasitic worms, animal muscles, and some micro-organisms such as yeasts.

ADVANTAGES OF SPORE FORMATION

Q.1 How will an organism be benefited if it reproduces through spores?

Ans: - An organism (like Rhizopus) be benefited if it reproduces through spores due to several reasons:-

1.      Spores are covered by thick walls. This prevents the spore from dehydration, under unfavourable conditions. This increases the survival rate of spore and the organisms.

2.      Spores are mostly dispersed by wind. This increases the number of organisms far and wide. This prevent the competition between growing spores at one place,

3.      Large numbers of spores are produced in one sporangium. This increases the survival rate of the species.

4.      All the daughters formed through spores are genetically similar.

ADVANTAGES OF VEGETATIVE PROPAGATION

Q. Why is vegetative propagation practiced for growing some type of plants?

Ans: - Vegetative propagation is practiced for growing some type of plants like sugarcane due to several reasons:

1.      YIELD OF SEEDLESS PLANTS:-Vegetative propagation is practiced for growing such plants which have lost their capacity to produce seeds or produce non-viable seed.

Ex: - This method is used for some seedless plants like Banana, seedless grapes, oranges, Rose, jasmine, sugarcane, pineapple etc.

2.      QUICKER METHOD: - Vegetative propagation is a quicker method of rising of crops. Thus, plants raised by vegetative propagation flowers and fruits earlier than those produced from seeds.

Ex:-Potato requires only 3 months for forming a new crop if raised from tubers. And it takes 15 months if raised from seeds.

3.      GENETIC UNIFORMITY:-Plants produced are genetically similar to the parent characteristics. Thus, good qualities of varieties can be maintained for a long time.

How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?

Movement of a shoot towards light	Movement of leaves of sensitive plant
It is a tropic movement which depends on the direction of stimulus applied.	It is a nastic movement that does not depend upon the direction of stimulus applied.
The stimulus is light.	The stimulus is touch(or contact stimuli)
It is caused by the unequal growth on the 2 sides of the shoot.	It is caused by the sudden losss of water from the swellings at eh base of leaves.
This type of movement is directional and is growth dependent	This movement is independent of growth

How do auxins promote the growth of a tendril around a support?

·         Tendrils are the thin, thread-like growths on the stems or leaves of climbing plants. Tendrils are sensitive to the touch (or contact) of other objects.

·         When the tip of the tendril touches a support, then the auxins (plant hormone) present in its tip move to that side of tendril which is away from the support.

·         Because Auxin promotes growth so the side of the tendril which is away from the support grows faster (and becomes longer) than the side which is in contact with the support. This makes the tendril to curve (or bend) towards the support.

·         This curving tendril can then encircle the support & appear as a watch spring.

What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?

Movement in sensitive plants	Movement in our legs
The movement that takes place in a sensitive plant such asMimosa pudica occurs in response to touch (stimulus).	Movement in our legs is an example of voluntary actions
For this movement to occur, the plant cells change shape by changing the amount of water in them.	In animal muscle cells, some proteins are found which allow the movement to occur

The movement in the leaves of a sensitive plant takes place due to the sudden loss of water in the pad-like swellings (called pulvini) at the base of all the leaves.

The loss of water makes the pulvini limp leading to drooping and folding of leaves.