Explain budding in Hydra with the help of labelled diagrams only. a mature Sporogyra filament attains considerable length ? Repeated cell division at one specific site leads to the formation of an outgrowth called as bud. Spore formation is a common method of an asexual reproduction in bacteria and most of the fungi. Very often if the conditions are highly favourable, a chain of buds is formed. The zygote divides several times to form an embryo within the ovule. The process of copying the DNA leads to some variations each time. Question 118. (iv) No special organs are present for reproduction. Plants such as banana, orange, rose and jasmine are produced by vegetative propagation because they lose the capacity to produce seeds. Offspring obtained from gametogenesis has just one parent; there are not any chances of variation in their chromosomes. Under which mode of reproduction is vegetative propagation placed and why? (b) Asexual reproduction in Hydra and yeast takes place by budding. In multicellular organisms with simple body organization budding, fragmentation may work but in complex multicellular organisms only sexual reproduction takes place. Placenta provides a large surface area for glucose and oxygen to pass from the mother to the embryo. Fertilisation is the fusion of male gamete with the female gamete (or egg). Answer: stalk and Anther i.e. banana, rose, jasmine. Suggest three contraceptive methods to control the size of human population which is essential for the health and prosperity of a country. Answer: Millions of sperms are released into the vagina at one time. This causes the dough to expand or rise as gas forms pockets or bubbles. Attached to each testis is a highly coiled tube called epididymis. (Delhi 2015) The formation of the male germ cell (sperms) takes place in the testes (male reproductive organ). Benefits: Sexual Reproduction: When reproduction takes place as a result of the fusion between two gametes, one from each parent, it is called sexual reproduction. The new plants produced by vegetative propagation will be exactly like the parent plant. [117] Candida glabrata is the second most common Candida pathogen after C.albicans, causing infections of the urogenital tract, and of the bloodstream (candidemia). This leads to diversity in the population which helps in natural selection. Answer: It can happen through the use of vegetative parts of the plants, such as leaves, stems, and roots to produce new plants or through growth from specialized vegetative plant parts.. Ovaries produce female gamete (ovum or egg) and secrete female hormones (estrogen and progesterone). It is a place for copulation. Mechanical barrier method (use of condoms). This method of reproduction occurs in unfavourable conditions. To produce male sex hormone/testosterone. 15 to 28 days After releasing the egg, the follicle part produces corpus luteum which produces progesterone. Question 6. Therefore, amount of DNA remain constant. Sexual reproduction promotes diversity because it results from the separation of two gametes from two different and sexually distinct individuals. Ovary, oviduct, uterus Water does not provide required energy whereas sugar provides energy hence yeast multiplies in sugar solution. Ans: Tubectomy is the permanent method of contraception in women by removal of a section of fallopian tube. 3. Ovary How many follicles mature every month during the reproductive phase of human females? (ii) if zygote is not formed. Copper-T is a contraceptive method which prevents implantation of the zygote inside the uterus. When a mature ovum in a female body is not fertilized, it gets released into the fallopian tubes. This can cause problems for winemaking but could potentially also be used to advantage by using killer toxin-producing strains to make the wine. Moreover, minor alternations during the process of DNA copying result in the production of variations. What is contraception ? Puberty: The period during which adolescents reach sexual maturity and become capable of reproduction. (i) Do larger organisms have more number of chromosomes/cells ? Name the two reproductive parts of a bisexual flower which contain the germ cells. What are the basic features of asexual reproduction? The nucleus of the cell divides repeatedly producing many nuclei. Both the gametes are microscopic unicellular and have half the number of chromosomes as compared to the body cells. It should be avoided at all cost as it disturbs the male-female ratio in a population. The female sex organ is flask shaped called archegonium and produces a single egg. Question 132. (iv) Spirogyra Fragmentation 22. The uterus is richly supplied with blood to nourish the growing embryo. How are spores produced in sporangia of Rhizopus? In this page, you can find CBSE Class 10 Science Chapter 8 Extra Questions and Answers How do Organisms Reproduce Pdf free download, NCERT Extra Questions for Class 10 Science will make your practice complete. It plays an important role in continuous evolution of better organisms that may lead to the origin of new species. Answer: It enters the fallopian tube, known as ovulation. Educational problem In a family if there are more children, it becomes difficult to provide education to all with limited income. (ii) Viral infection causes AIDS, genital herpes. How will an organism be benefited if it reproduces through spores? What are the changes seen in girls at the time of puberty? (i) In Amoeba, asexual reproduction occurs by fission (binary and multiple). Number of chromosomes in both the gametes are equal hence a number of chromosomes in a female gamete of tobacco plant is 24. Question 4. Refer to answers 38 and 26. (i) Bacterial infections Why are budding, fragmentation and regeneration all considered as asexual types of reproduction? (ii) Bisexual flowers : The flower is said to be bisexual when both male and females parts, i.e., stamens and carpels, are present on the same flower. Explain in brief the structure of its female reproductive parts. Penis: It is the organ which is used to introduce semen into the female body. Question 26. Regeneration does not occur i Amoeba because regeneration is carried out by specialised cells which are not present in non-regenerating organisms like Amoeba. Planaria reproduces by regeneration. In cross pollination pollen is transferred from one flower to another. This fertilized egg (zygote) gets implanted in the lining of uterus which later forms embryo. So when a sperm and an egg fuse together during fertilisation, then the zygote formed will have 23 + 23 = 46 chromosomes, which is the normal number of chromosomes in humans. Pollination is the transfer of pollen grains from the anther to the stigma Of a flower whereas fertilization is the fusion Of male gamete with female gamete (egg). Many plants can be grown from one plant by vegetative propagation. When a sourdough starter is used, flour and water are added instead of sugar; this is referred to as proofing the sponge. (b) Asexual reproduction by multicellular organisms: Each fragment has the capacity to form a new individual. Vegetative propagation is a type of asexual reproduction occurs in plants. Ureter of each kidney leaves from the renal pelvis. Large number of pollen grains are formed inside anther. The doctor refused to perform the test in order to prevent female feticide which leads to shocking drop in child sex ratio. Each piece regenerates into a new Planaria. A special disc-like structure is made between the embryo and the uterus wall called placenta. What are the functions performed by the testis in human beings ? Dry slice of bread offers nutrients but not moisture hence hyphae fail to grow. (d) I, II and IV How is the sperm genetically different from the egg? Binary fission is the division of adult parental body into two nearly equal daughter cells. After implantation, a disc-like special tissue develops between the uterus wall (called uterine wall) and the embryo (or fetus), which is called placenta. This cycle takes place every month and is known as menstruation. 22. Plasmodium divide into many daughter cells by binary multiple fission. Two examples: Explain how the transmission of such diseases be prevented? These structures germinate into new individuals under favourable conditions. (AI 2014) (a) Ovary Question 28. When the oxygen is depleted, fermentation begins, producing ethanol as a waste product; however, this evaporates during baking.[74]. Change occurs in ovaries during menstruation cycle are-. Ans: An organism is benefited if it reproduces through spores as spores are enclosed by thick walls that protect them until they come into contact with appropriate moist surface and can begin to grow. Blueprints of body design are stored in the DNA. DNA copying in reproduction is the basic event. It occurs by process of growth and development. Thus, blueprints of the body design are stored in the DNA. Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. For e.g. That is, if the individual is somehow cut or broken up into many pieces, many of these pieces grow into separate individuals. This is an asexual method of reproduction. How does Plasmodium reproduce. It takes place by natural or artificial means. Two functions of ovary of human female are: Question 59. Give two symptoms of STDs. Reproduction in human beings : The reproductive organs of human beings are called gonads. State the genetic constitution of a sperm. Candida blankii has been detected in Iberian ham and meat. (i) Genetic variations occur of because DNA copying mechanism is not absolutely accurate. Answer: Once the male and female gametes are in close vicinity, they fuse and fertilisation is accomplished. Give two reasons for the appearance of variations among the progeny formed by sexual reproduction. 15. (i) Implantation of zygote At the time of birth each girl child already contains thousands of immature ova. Offspring produced have genetic makeup identical to the parent plant, no variation occurs. According to new CBSE Exam Pattern,MCQ Questions for Class 10 Science pdfCarries 20 Marks. Ans: The product of fertilization is zygote. Answer: In fission the parental identity is lost. What is multiple fission? (b) Mention the role of gamete and zygote in sexually reproducing organisms. Now, as fertilization doesnt occur this lining is not needed. Answer: For this reason, a pure yeast culture is usually added to the must; this yeast quickly dominates the fermentation. (b) Role of Gamete : Gametes are the reproductive cells involved in sexual reproduction having half of the chromosome. is an important study resource for CBSE Class 10 students. (d) Fallopian tube Question 2. What are the functions performed by the testis in human beings? Why do offsprings formed by asexual reproduction exhibit remarkable similarity? They may suffer from reproductive tract infections. The function of cotyledon is to store food for the future plant or embryo. The budding yeasts or "true yeasts" are classified in the order Saccharomycetales,[12] within the phylum Ascomycota. Penis is male copulatory organ. Any desirable features of the parent plant can be replicated in the new plants. Question 9. In Rhizopus, tubular thread-like structures bearing sporangia at their tips are called. What is vegetative propagation? During spore formation, knob like structure called sporangium develops from the fungal hypha. To produce a male reproductive hormone called testosterone which is responsible for producing sperms as well as secondary sexual characteristics in males. What is the need of population control? (iv) Prostrate glands: To secrete the fluid which provides nutrition and medium for transport of sperms. Refer to answer 122(b). Role of placenta: Question 56. The correct sequence of reproductive stages seen in flowering plants is [NCERT Exemplar] It produces variations in organisms which is the basis of evolution of new species. Budding occurs in yeast, some protozoans and certain lower animals. Elaborate any one method. Anthers produces male gametes. Further growth of the pollen tube occurs only towards its tip. The buds can also drop to the ground together with the leaf and then grow to produce new plants. What are the functions of testis in the human male reproductive system ? (i) Refer to answer 88 (a) (i). Why cannot fertilisation take place in flowers if pollination does not occur? Question 12. Thus, this is the only method of reproduction and continuation of such species. Leishmania (causes kala-azar), Euglena (longitudinal), Paramecium (transverse) etc. Justify. More number of organisms produces counterbalances the mortality that arises due to various factors. List four categories of contraceptive methods. Maths Students who are looking for the better solutions, they can download. thick walls that protect them from adverse conditions. (a) After landing of stigma, the pollen grain does not pass down the stigma. Ans: Difference between internal and external fertilization is as follows: The internal fertilization process takes place inside the body of females when male gametes are discharged inside. Many daughter cells develop which on liberation grow into adult organisms. (c) Refer to answer 123 (c). It promotes diversity of characters or helps to show the variations which enhance the survival chances. The most common top-cropping brewer's yeast, S.cerevisiae, is the same species as the common baking yeast. Answer: (a) A represents stigma. Answer: Most yeasts grow best in a neutral or slightly acidic pH environment. Simple animal like Hydra shows regeneration. through the vagina. (b) fusion of nuclei of male and female gamete. Safe sex vs HIV/ AIDS. Hepatitis is a water borne viral disease which affects liver. Which species is likely to have comparatively better chances of survival the one reproducing asexually or the one reproducing sexually? We hope this detailed article on NCERT Solutions For Class 10 Science Chapter 8 How Do Organisms Reproduce? Answer: The rate Of birth and death in a given population determine its stability. Sequoia sempervirens (/ s k w . Cervix IV. A boy pushing a wallNo work is done if the force you exert does not make the object move in the samedirection as the force you exerted.Force, Fdirection of motionFigure 3. The new plants produced by artificial vegetative propagation are exactly like the parent plants. Sepals are green structures that protect the inner parts when the flower is in bud stage. (Delhi 2016) When these spores land on food or soil, under favourable conditions, they germinate into new individuals. If the egg is not fertilized it remains for one day. Following are the reasons for that. Modified root tubers of sweet potato also grows into a new plant. Such organisms are called bisexual (hermaphrodite). Hence reproduction linked to population of the species. NCERT Exemplar Solution Class 10 Science will cover important concepts that are more likely to be asked in examinations. (iii) Intrauterine contraceptive devices : Intrauterine contraceptive devices such as copper-T are placed safely in the uterus by a skilled doctor. (a) Ovary Many other common examples of vegetatively propagating plants are onion, banana, garlic, ginger, turmeric, bryophyllum and water hyacinth. It leads to formation of variations in individuals. What happens when a Planaria gets cut into two pieces? The uterine wall thickens that is richly supplied with blood. In a tobacco plant, the male gametes have twenty-four chromosomes. Question 1. (iv) Prostate gland : It is a single large gland that surrounds the urethra and produces a milky, slightly acidic secretion. The ovule develops a tough coat and is gradually converted into a seed. How does Plasmodium reproduce. Answer: Answer: Asexual Reproduction: It is extremely useful as a means of rapid multiplication. This means that a species (animal or plant) can adapt quickly to changes in its surroundings. These in turn may allow few individuals of a population to survive in an altered niche and becomes the basis of evolution and over time. (b) Write the structure and functions of placenta in a human female. A number of diseases occur as a result of sexual intercourse if one of the partners is infected. The terminal part of fallopian tube is funnel-shaped with finger-like projections called fimbriae lying near ovary. In this method, new plants are obtained from the parts of old plants (like stems, roots and leaves), without the help of any reproductive organs. 18. (Delhi 2012) (Foreign 2016) (a) pollen grain and upper surface of stigma. Natural Vegetative Propagation: In some plants like guava, sweet potato, dahlia, roots sprout and grow into new plants during favourable conditions. (c) Name the parts of flower that develop after fertilisation into: Answer: It is the site of fertilisation and helps in the conduction of ovum or zygote towards uterus by ciliary action and peristalsis. No, process of reproduction follows a common pattern and is not dependent on the number of chromosomes. Ans: Puberty is the process of physical changes when the reproductive system is functionally active or starts producing ova or sperm. These are called secondary sexual characters. Wheat, Tomato, Rose, Pea, Gram, Corn, Banana (Foreign 2014) Question 24. Which of the following is not a pan Of the female reproductive system in human beings ? The genetical similarity is maintained in the plants. Why does regeneration not occur in the latter? (c) The amount of DNA remain constant in each new generation because of formation of haploid gametes. Fallopian Tube: The egg is carried from the ovary to womb/uterus through a thin oviduct or fallopian tube. The process of formation of entire organism from the body parts of a fully differentiated organism is called regeneration. [49] Haploid cells may then reproduce asexually by mitosis. (d) gametes, embryo, zygote, seedling The pollen grains produce male gametes which fuse with (egg cel I) female gamete present in the ovule. (a) Refer to answer 73. Answer: (iii) Amoeba Fission Write the functions of the following in human female reproductive system. The method by which Spirogyra reproduces under favorable conditions is fragmentation. Ovules contain female gamete or egg. (ii) Oviduct (Fallopian tube): It is a site where egg and sperms meet and fertilisation takes place. The breast size begins to increase with darkening of the skin of the nipples at the tip of breasts. 27. The plant contributing scion should have large sized fruits and the plant contributing stock should have a deep root system. The narrow end of the uterus is called cervix. Expand AIDS. A girl pushing a chairNo work is done if the force you exert does not make the object move.Force, Fno motionFigure 2. Prostate gland Prostate gland secretions provide fluid medium to sperm, which makes the transport easy and also provide nutrition to sperms. Answer: 16. (iii) Female germ cell Is this method sexual or asexual? (Foreign 2015) NCERT Solutions for Class 10 ScienceChapter 1, NCERT Solutions for Class 10 ScienceChapter 2, Periodic Classification of Elements Class 10, NCERT Solutions for Class 10 ScienceChapter 7, NCERT Solutions for Class 10 ScienceChapter 8, NCERT Solutions for Class 10 ScienceChapter 9, NCERT Solutions for Class 10 ScienceChapter 10, NCERT Solutions for Class 10 ScienceChapter 11, NCERT Solutions for Class 10 ScienceChapter 12, NCERT Solutions for Class 10 ScienceChapter 13, NCERT Solutions for Class 10 ScienceChapter 14, NCERT Solutions for Class 10 ScienceChapter 15, NCERT Solutions for Class 10 ScienceChapter 16, CBSE Previous Year Question Papers Class 12, CBSE Previous Year Question Papers Class 10. (ii) Scrotum; (c) on maturation sporangia of Rhizopus bursts? The process involves only one cell or one parent, so is called uniparental reproduction. Asexual reproduction involves only one parent. (AI 2014) Sperms are motile and are produced by male individuals whereas ova or eggs are non-motile and produced by female individuals. [92], In 1920, the Fleischmann Yeast Company began to promote yeast cakes in a "Yeast for Health" campaign. Contraceptive methods are adopted: Function of the fallopian tubes: It is the site of fertilization between the male and the female gametes and formation of the zygote early embryo. State in brief the changes that take place in a fertilised egg(zygote) till birth of the child in the human female reproductive system. (b) yeast Mark one change associated with sexual maturation in males. Recent research on eight Brettanomyces strains available in the brewing industry focused on strain-specific fermentations and identified the major compounds produced during pure culture anaerobic fermentation in wort. Chemical method In this method certain drugs (containing hormones) are used by the females. Is this method sexual or asexual? It helps in preventing STDs especially AIDS. This method is an asexual means of reproduction. (i) The two sexually transmitted diseases (STDs) are gonorrhoea and syphilis. Archaeologists digging in Egyptian ruins found early grinding stones and baking chambers for yeast-raised bread, as well as drawings of 4,000-year-old bakeries and breweries. Pollination results in the deposition of related pollen grains over the receptive stigma of the carpel. Give examples of each. So, when a sperm and an egg fuse together during fertilisation, then the zygote formed will have 23 + 23 = 46 chromosomes, which is the normal number of chromosomes. (c) In sexual reproduction, the offsprings are not exactly identical to the parents or to one another. (Delhi 2017) (b) We can develop new plants from the leaves of Bryophyllum. Examples of self pollination are wheat, rice etc. (i) Name the organ that produces sperms as well as secretes a hormone in human males. Question 8. (b) Testes produce male sex hormone testo-sterone. This cycle is known as menstruation. Testes release a male sex hormone called testosterone whose function is to: brings about changes in appearance seen in boys at the time of puberty; and. Answer: Answer: Plants produced are genetically identical plants (clones) that have similar characteristics to the parent. oxygen to pass from the mother to the embryo. (c) List two advantages of vegetative propagation over other modes of reproduction. Which among the following diseases is not sexually transmitted? Rhizopus body is made up of thread-like structures called hyphae. List four advantages of vegetative propagation. What is asexual reproduction? (AI 2017) Differences between self pollination and cross pollination are as follows: Pollination is important because it brings pollen grains to the female reproductive part (carpel) of the plant that leads to fertilisation. This is everything weve got in one long list! It is called double fertilisation. Describe sexually transmitted diseases (STDs) and mention the ways to prevent them. Population of organisms reside in well-defined places or niches in the ecosystem. Where does it occur? Hair grow under armpits and pubic region. The ratio is 1 : 2 Sperms contain either X or Y chromosome whereas an egg will always have an X chromosome. Mexico, the United States, and Canada may be the largest and most prominent countries in North America, but this continent the third largest in the world is home to 23 sovereign states and 23 non-sovereign territories (iii) State the importance of the part C. Question 5 Question 57. Name the method by which Spirogyra reproduces under favourable conditions. List three conditions favourable for spores to germinate and grow. One pair of testes are present in a bag-like structure called scrotum which lies outside the abdominal cavity, hence they are extra abdominal in position. In ovary, the male gamete of pollen combines with the female gamete or egg present in ovule to form a fertilised egg. 3. (ii) Body of organism divides by mitotic divisions into two or more daughter cells. (Delhi 2011) Question 1. (b) List two bacterial diseases which are transmitted sexually. 15. Seedless plants can be obtained by artificial vegetative propagation. After detaching from the parent, and if conditions are suitable, they germinate directly or indirectly into a new individual. Many fully differentiated organisms use this ability as a mode of reproduction and give rise to new individual organisms from their body parts. Which contraceptive method changes the hormonal balance of the body? (2020) Formation of sperms in testes and ova in ovary is called gametogenesis. Ans: In the age group of 10-14 following changes occur in boys: In the age group of 10-14 following changes occur in girls: 2. The flow of blood continues for 2 to 8 days. Answer: State two advantages semen offers to the sperms. Mention the events taking place when the ovum is fertilized in the fallopian tube till it is implanted in the uterus of a human female. What is AIDS? So, the uterus prepares itself every month to receive and nurture the growing embryo. Advantages of vegetative propagation : Vegetative propagation is useful for plants those have lost the capacity to produce seeds, e.g. This allows you to revise the chapter ideally and get an idea about the type of questions that can be asked in the board examination. Budding usually occurs when food is available in plenty. This would be required for nourishment and further development of embryo. [NCERT Exemplar] Sprint X Term 2: How Do Organisms Reproduce | CBSE Class 10 Biology Ch 8 | Vedantu Class 9 & 10, How Do Organisms Reproduce? On getting cut into many pieces, each piece regenerates into new Planaria. The difference between binary fission and multiple fission is as follows: Basic feature for asexual reproduction are as follows: Cells derived from a standard ancestor are referred to as clones. 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