important for 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.

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.