Assertion (A) : Reproduction, like any other life process, is essential to maintain the life of an individual organism. Reason (R) : Reproduction involves creation of a DNA copy and additional cellular apparatus by the cell involved in the process. (Use options from Q8)
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(D) / Assertion (A) is false and Reason (R) is true. (1 Mark)
(A) Name the reproductive and non-reproductive parts of bread mould (Rhizopus). (B) Give any two advantages of sexual reproduction in plants.
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Reproductive part: tiny blob –on- a-stick structure/Sporangia. (½ Mark) Non reproductive part is thread like structure/ hyphae. (½ Mark) Advantage of sexual reproduction in plants. (i) Sexual reproduction results in genetic variation which are useful for ensuring survival of species under changing environmental condition. (½ Mark) (ii) It results in the formation of seeds that develops into seedling under appropriate condition. (½ Mark) (or any other relevant advantage)
A farmer wants to grow banana plants genetically similar to the plants already available in the fields. Which of the following method would you suggest for this purpose :
Spirogyra, despite being a multi-cellular organism, still shows a simple reproductive method. Select the correct option with regard to reproduction in Spirogyra :
(a)Asexual reproduction by division of cells into two cells
(b)Sexual reproduction by division of cells into many cells
(c)Asexual reproduction by breaking up of Spirogyra filaments into smaller parts
(d)Sexual reproduction by the formation of gametes after meiosis of cells of filaments followed by fusion of male and female gametes
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(C) / Asexual reproduction by breaking up of Spirogyra filaments into smaller part. (1 Mark)
Assertion (A): Variations are not often seen in off-springs produced by asexual reproduction. Reason (R) : DNA molecule generated by replication is not similar to the original DNA.
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(C) / Assertion(A) is true, but Reason(R) is false. (1 Mark)
Assertion (A) : Bacteria produced as a result of asexual reproduction would be similar. Reason (R) : There would be only minor differences between the bacteria generated due to small inaccuracies in DNA replication.
(a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
(b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
(c)Assertion (A) is true, but Reason (R) is false.
(d)Assertion (A) is false, but Reason (R) is true.
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(A)/ Both A and R are true and R is the correct explanation of A. (1 Mark)
Assertion (A): In regeneration, organisms have the ability to give rise to new individual organisms from their body parts. Reason (R): Simple animals like Hydra and Planaria show regeneration.
(a)Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
(b)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
(c)Assertion (A) is true, but Reason (R) is false.
(d)Assertion (A) is false, but Reason (R) is true.
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(B) (A) and (R) are true but (R) is not the reason (1 Mark)
Which of the following statements correctly identify the advantages of vegetative propagation? (i) Plants can bear flowers and fruits earlier than those produced by seeds. (ii) The new plants develop as an outgrowth on the parent plant and can be removed easily. (iii) Plants that have lost the capacity to produce seeds can be propagated. (iv) All plants produced are genetically similar to parent plant.
This freshwater organism is known for its amazing ability to reproduce by any of the two methods – either regeneration or budding. Identify the organism.
Give reasons for the following : (a) Adrenal gland is known as the stress gland of the body. (b) Prenatal sex determination is banned in India. (c) Vegetative propagation is advantageous in some plants.
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(a) Because adrenal gland secretes adrenaline hormone that enables the animal body to face a scary situation. (1 Mark) (b) To prevent female foeticide. (1 Mark) (c) Plants raised by vegetative propagation can bear flowers and fruits earlier than those produced from seeds / Such methods also make possible the propagation of plants such as banana, orange, rose and jasmine that have lost the capacity to produce seeds / All plants produced are genetically similar enough to the parent plant to have all its characteristics. (1 Mark)
Given below are certain situations. Analyse and describe what would happen when : (i) Spores are liberated from blob-like structures of the bread mould? (ii) Leaves of bryophyllum fall on wet soil ? (iii) A pollen from different species land on the stigma of totally unrelated species ? (iv) Copper-T is placed in the uterus of a human female ? (v) Spirogyra breaks into smaller fragments upon maturation ?
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(i) When spores land on a substance and get adequate moisture and temperature, it will develop into new Rhizopus. (1 Mark) (ii) New plants grow from the buds located in the notches of the leaf. (1 Mark) (iii) The pollen tube will not be formed. / No fertilisation will take place. (1 Mark) (iv) Fertilization/Pregnancy will be prevented. (1 Mark) (v) Each fragment or piece grows into a new individual organism. (1 Mark)
(i) Sugarcane does not produce seeds so name the process through which it will be able to reproduce. (ii) List any two advantages of this method. (iii) Besides sugarcane, give two more examples of plants that reproduce by this method. (iv) Why regeneration is not possible in all the types of animals ?
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(i) Vegetative propagation. (1 Mark) (ii) Advantages: - • Plants raised by vegetative propagation can bear flowers and fruits earlier than those produced from seeds. • Plants produced by vegetative propagation are genetically similar to the parent plant. • Plants that have lost the capacity to produce seed can reproduce by Vegetative propagation. (any two advantages) (1+1 Marks) (iii) Roses, grapes, banana, orange, jasmine etc. (any other two examples) (½ + ½ Mark) (iv) Regeneration is carried out by specialised cells. The organism which have those cells only can show regeneration. (1 Mark)
(a) Name the most suitable method of raising a banana plant. Is this mode of reproduction sexual or asexual ? List any three advantages of growing plants by such a method.
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(a) • Vegetative Propagation. (1 Mark) • This is asexual mode of reproduction. (1 Mark) Advantages (1) Plant raised by vegetative propagation can bear flowers and fruits earlier than those produced from seeds. (2) All plants produced are genetically similar. (3) Helpful to the plants which have lost the capacity to produce seeds. (Any other relevant point) (1x3 Marks) (5 Marks)
(b) State two differences between pollination and fertilization.
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Pollination Fertilization i) It is the transfer of pollen i) It is the fusion of male gamete 1 grains from anther to the with the female gamete. suitable stigma. ii) It occurs in plants. ii)It occurs in both plants and 1 animals. (any other suitable difference) 2
(a) Which technique would you use for the propagation of varieties of grapes and roses ? (b) Mention the parts of plants that can grow vegetatively. (c) State the role of pollen grains in a flower.
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Grafting for grapes and rose. 1 Many parts of the plants like – stem, root and leaves can develop into new plant. 1 Pollen grains produce / carry male gametes for fertilization in plants. 1
(a) How is the process of pollination different from fertilization ? (b) Where is the zygote located in the flower after fertilization ?
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(a) Pollination 1. Transfer of pollen grains from anther to the stigma of the flower is called pollination. 2. It is followed by fertilization in plants (1 Mark) Fertilization 1. The process of fusion of male and female gametes to form zygote is called fertilization. 2. It is followed by seed formation in plants and embryo development in animals (1 Mark) (any other difference) (b) Inside the Ovule which is present in the ovary. (1 Mark) (3 Marks)
(i) In an angiospermic flower, fertilization is said to take place when male gametes carried in the pollen tube fuse with the female gamete, present in the embryo sac. This results in lot of changes in different parts of the flower. State the changes taking place in the following structures of flower post fertilization : (a) Zygote (b) Ovule (c) Ovary (d) Sepals (ii) Define germination.
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(i) (a) Zygote: It divides several times to form an embryo within the ovule. (1 Mark) (b) Ovule: It develops a tough coat and is gradually converted into a seed. (1 Mark) (c) Ovary: Grows rapidly and ripens to form a fruit. (1 Mark) (d) Sepals: They shrivel and fall off. (1 Mark) (ii) Germination is the process when the mature seed develops into a seedling under appropriate conditions. (1 Mark)
Attempt either subpart (a) or (b) : (a) (i) Sugarcane and roses are mostly grown by vegetative propagation. Define this mode of reproduction. (ii) List two advantages of vegetative propagation. (iii) Distinguish between unisexual and bisexual flowers. Give one example of each kind.
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(a) (i) Reproduction in which plant parts like root, stem and leaves develop into new plants under appropriate conditions is called as vegetative propagation. (1 Mark) (ii) Advantages of vegetative propagation: - • Plants raised by this method can bear flowers and fruits earlier than those produced from seeds. • All the plants produced are genetically similar to the parent plant to have all its characteristics. • Propagation of plants such as banana, orange, rose and jasmine that have lost the capacity to produce seeds. (any two or any other suitable advantage) (1+1 Marks) (iii) Unisexual flower 1 Contains either Stamens (male reproductive part) or Pistil (female reproductive part). (1 Mark) 2 Eg - Papaya or watermelon (1 Mark) Bisexual flower Contains both Stamens (male reproductive part) and Pistil (female reproductive part) Eg - Hibiscus or mustard (any other suitable difference or example)
Attempt either subpart (a) or (b) : OR (b) (i) Differentiate between self-pollination and cross-pollination. (two points) (ii) Explain how does pollination lead to fertilisation in flowering plants. (iii) Name the end-products of sexual reproduction in plants.
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(b) (i) Self-pollination 1 Transfer of pollens from stamens to stigma occur in the same flower. (1 Mark) 2 Polling agents may or may not be required. (1 Mark) 3 Genetic variation may or may not occur. (1 Mark) Cross-pollination Transfer of pollens from stamens to stigma occur from one flower to another. Polling agents like wind, water or animals are always required. Genetic variation always occur. (any two, any other suitable difference) (ii) After pollination, the pollen lands on a suitable stigma, a tube grows out of the pollen grains and travels through the style to reach the ovary. (1 Mark) A female germ cell present inside ovary fuses with a male germ cell to form zygote and this process leads to fertilization. (1 Mark) (iii) End products of sexual reproduction- • Seed. (½ Mark) • Fruit. (½ Mark)
Given below are certain situations. Analyse each and describe its possible impact : (i) A population of bacteria living in temperate waters whose temperature increased by global warming. (ii) The sperm encounters the egg when it reaches the oviduct in human females. (iii) Self pollination does not occur in a flower that contains only pistil. (iv) Egg does not get fertilised in a human female. (v) When the seed is placed under appropriate condition of water and air in the soil ?
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(i) Most of these bacteria would die, but the few variants resistant to heat would survive and grow further. (1 Mark) (ii) Fertilization occurs to form a zygote. (1 Mark) (iii) Cross pollination may occur leading to fruit formation. / No fertilization. / No fruit formation. (1 Mark) (iv) If the egg is not fertilised, the thick and spongy lining of the uterus breaks and comes out through vagina as blood and mucus, known as menstruation. / Menstruation will take place. (1 Mark) (v) The seed will develop into a seedling. / Germination will take place. (1 Mark)
Attempt either (a) or (b) : (a) (i) Name an organ that helps in the formation of male germ cells in humans and also mention the condition that favours the formation of male germ cells. (ii) In male reproductive system, write the pathway followed to deliver male germ cells to the site of fertilisation. (iii) Mention the main physical feature of the male germ cell that helps it move towards the female germ cell.
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(a) (i) * Organ - Testes (1 Mark) * Conditions - Requires a lower temperature than the normal body temperature/Secretion of testosterone. (1 Mark) (ii) The sperms formed in the testes are carried by Vas deferens and delivered to urethra (Common passage for both sperms and urine). / Testes $\rightarrow$ Vas deferens $\rightarrow$ Urethra (2 Marks) (iii) Long tail of sperms. (1 Mark) OR (b) (i) * Mechanical barrier / Female condom (Diaphragm)/ similar covering worn in vagina. (2 Marks) * Oral contraceptives/ Oral pills * Copper - T/loops. (Any two methods, Any other method) (ii) Surgical methods * Vas deferens in the male is blocked / Vasectomy (2 Marks) * Fallopian tube in the female is blocked /Tubectomy (iii) * Bacteria - Gonorrhoea / Syphilis (any other example) (½ Mark) * Virus - Warts / AIDS (any other example) (½ Mark)
(i) Name the special tissue inside the uterus that provides nutrition to the developing embryo. Describe its structure. State its two functions besides nutrition. (ii) Write any two sexually transmitted diseases in humans and their causative microbial agents.
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(i) $\bullet$ Placenta (1 Mark) $\bullet$ This is a disc which is embedded in the uterine wall. It contains villi on the embryo side of the tissue. On the mother's side are blood spaces which surround the villi. (1 Mark) Functions: $\bullet$ Removes wastes produced by embryo. ($\frac{1}{2}$ Mark) $\bullet$ Provides a large surface area for oxygen to pass from mother to embryo. ($\frac{1}{2}$ Mark) (ii) Name of the disease: Gonorrhoea / Syphilis, Microbial agent: Bacteria (1 Mark) Name of the disease: Warts / HIV – AIDS, Microbial agent: Virus (1 Mark) (any other)
From the following, identify the sexually transmitted diseases caused by bacteria. (i) Warts (ii) Gonorrhoea (iii) AIDS (iv) Syphilis Choose the correct option :
Radha has three children. She does not want to have more children. Radha visits a nearby hospital, to know the methods to prevent pregnancy. (i) Mention the name of any two ways other than the surgical methods, following which Radha can avoid unwanted pregnancies. (ii) Name the surgical methods to prevent pregnancy. (iii) Give one example each of sexually transmitted diseases caused by bacteria and virus.
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(a) (i) * Organ - Testes (1 Mark) * Conditions - Requires a lower temperature than the normal body temperature/Secretion of testosterone. (1 Mark) (ii) The sperms formed in the testes are carried by Vas deferens and delivered to urethra (Common passage for both sperms and urine). / Testes $\rightarrow$ Vas deferens $\rightarrow$ Urethra (2 Marks) (iii) Long tail of sperms. (1 Mark) OR (b) (i) * Mechanical barrier / Female condom (Diaphragm)/ similar covering worn in vagina. (2 Marks) * Oral contraceptives/ Oral pills * Copper - T/loops. (Any two methods, Any other method) (ii) Surgical methods * Vas deferens in the male is blocked / Vasectomy (2 Marks) * Fallopian tube in the female is blocked /Tubectomy (iii) * Bacteria - Gonorrhoea / Syphilis (any other example) (½ Mark) * Virus - Warts / AIDS (any other example) (½ Mark)
OR (b) Radha has three children. She does not want to have more children. Radha visits a nearby hospital, to know the methods to prevent pregnancy. (i) Mention the name of any two ways other than the surgical methods, following which Radha can avoid unwanted pregnancies. (ii) Name the surgical methods to prevent pregnancy. (iii) Give one example each of sexually transmitted diseases caused by bacteria and virus.
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(b)(i) • Mechanical barrier / Female condom (Diaphragm)/ or similar covering worn in vagina • Oral contraceptives/ Oral pills • Copper - T / loops. (Any two methods, Any other method) (ii) Surgical methods • Vas deferens in the male is blocked / Vasectomy • Fallopian tube in the female is blocked /Tubectomy (iii) Bacteria - Gonorrhoea / Syphilis (any other example) Virus - Warts / AIDS (any other example)
(b) What are sexually transmitted diseases ? Name any one sexually transmitted disease caused by virus and a bacterium. List any two contraceptive methods with their advantages.
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(b) • Sexually transmitted diseases are the diseases which spread by sexual contact with an infected person. (1 Mark) • By Virus $\rightarrow$ HIV AIDS / warts. (1 Mark) • By Bacterium $\rightarrow$ Gonorrhoea / Syphillis. (1 Mark) (any one disease) Contraceptive methods (i) Mechanical barrier/condom: It prevents sperm from reaching the egg. (ii) Contraceptive pills/Hormonal methods: Changing hormonal balance so that eggs are not released and fertilization cannot occur. (iii) Loops or Copper-T: These are placed inside the body to prevent pregnancy. (iv) Surgical method: In both (vas deferens blocking and fallopian tube blocking) fertilisation does not take place. (Any two of the above points) (2 Marks) (5 Marks)