1. If the information is changed, different proteins will be made. Different proteins will eventually lead to altered body designs.
2. This creates two copies of the DNA in a reproducing cell, and they will need to be separated from each other.
3. Effectively, a cell divides to give rise to two cells.
4. As a result, the DNA copies generated will be similar, but may not be identical to the original.
5. Some of these variations might be so drastic that the new DNA copy cannot work with the cellular apparatus it inherits. Such a newborn cell will simply die.
6. This inbuilt tendency for variation during reproduction is the basis for evolution.
7. A basic event in reproduction is the creation of a DNA copy which bring variation. Creation of DNA copy brings variation
8. 1. What is the importance of DNA copying in reproduction? 2. Why is variation beneficial to the species but not necessarily for the individual?
9. Effectively, a cell divides to give rise to two cells.
10. This inbuilt tendency for variation during reproduction is the basis for evolution.
11. Maintenance of body design features that allow the organism to use that particular niche.
12. If there were a population of bacteria living in temperate waters, and if the water temperature were to be increased by global warming, most of these bacteria would die, but the few variants resistant to heat would survive and grow further. Note: Global Warming takes long time to come in to effect. (may be 30 years) So, surviving bacteria must have passed through successive variations over generations.
13. Next generation bacteria passed through variations in such a way that, they will be able to cope up with increased temperature because, they have inherited changed body design during the process of DNA copying over generations.
14. Change in environmental conditions is a long term procedure. So, variation is not compulsory for the survival of an individual. But to survive with the changed environmental conditions an organism have to pass through successive variations over generations at its’ species level. Slowly they inherit some changes in the body design during the process of DNA copying over generations. Finally able to survive as a vitiated species.
15. Reproduction is linked to the stability of populations of species. Variation is useful for the survival of species over time.
16. 1. What is the importance of DNA copying in reproduction? 2. Write the importance of variation.
17. In case of animalsIn case of plants
18. Asexual ReproductionSexual Reproduction
19. In case of MoneraProtista, Fungi and in plants
20. A type of reproduction in which Fission only a single parent is involvedFragmentationRegeneration Vegetative propagation Budding Spore formation
21. Unicellular organism reproduces by dividing into two individuals. Example: Amoeba
23. Unicellular organism reproduces by divide into many daughter cells. Example: Plasmodium
24. Simply breaks up into smaller pieces upon maturation. These pieces or fragments grow into new individuals. Examples: Spirogyra
25. The individual is somehow cut or broken up into many pieces, many of these pieces grow into separate individuals. Example: Planaria
26. These cells multiply and make large numbers of cells. From this mass of cells, different cells undergo changes to become various cell types and tissues.
27. Fission in the unicellular organisms Fragmentation in the simple undifferentiated multicellular organisms Regeneration in the simple differentiated multicellular organisms
28. 1. How does binary fission differ from multiple fission? 2. Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
31. In Hydra, a bud develops as an outgrowth due to repeated cell division at one specific site. These buds develop into tiny individuals and when fully mature, detach from the parent body and become new independent individuals.
32. Development of new plant body from the existing buds along with maturity. Example: Potato eyes, Germinating BUD
33. Layering or grafting to grow many plants for agricultural purposes. can bear flowers and fruits earlier than those produced from seeds. Such methods also make possible the propagation of plants have lost the capacity to produce seeds. all plants produced are genetically similar enough to the parent plant
34. Formation and germination of tiny spores in the sporangium lead to production of new plant body under some conditions. Example: Rhizopus
36. Budding in the lower differentiated multicellular organisms Vegetative Propagation in complex multicellular plants and importance Spore Formation in simple multicellular organisms
37. 1. How will an organism be benefited if it reproduces through spores? 2. Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration? 3. Why is vegetative propagation practised for growing some types of plants? 4. Explain the process of spore formation .
39. Asexual ReproductionSexual Reproduction
40. It is a type of reproduction in which a male gamete fuses a female gamete to produce zygote which develop to form a new individual.
41. This inbuilt tendency for variation during reproduction is the basis for evolution.
42. Variation is useful for the survival of species over time.
43. It would therefore make sense if organisms came up with sexual reproductive modes that allowed more and more variation to be generated.
44. It results in re-establishment of the number of chromosomes and the DNA content in the new generation.
45. One germ-cell is large and contains the food-stores is called the female gamete or Ovum . While the other is smaller and likely to be motile is called the male gamete or Sperm.
46. It is a type of reproduction in which a male gamete fuses a female gamete to produce zygote which develop to form a new individual. Sexual reproduction brings variations Two variants combine to form new variation Specialized Germinating cells or gametes in complex organisms.
47. 1. What are the advantages of sexual reproduction over asexual reproduction? 2. How are the modes for reproduction different in unicellular and multicellular organisms? 3. How does reproduction help in providing stability to populations of species?
48. In case of plants
49. Petals have bright colour and help attracts insects for pollination. Sepals is a leaf life structure and protect flower at its immature state.
50. Pollens areAnther inside the anther, which contain two male gameteFilament
51. Stigma Ovule is inside theStyle Ovary, which contain one female gameteOvary
52. The flower may be unisexual (papaya, watermelon) when it contains either stamens or pistil.
53. The flower may be bisexual (Hibiscus, mustard) when it contains both stamens and Pistil.
54. If this transfer of pollen occurs in the same flower, it is referred to as self- pollination. It takes place in bi sexual plant
55. if the pollens are transferred from one flower to another of same kind, it is known as crosspollination. It is possible in both unisexual and bi sexual flower.
56. Parts of flower and their role Types of flower, unisexual and bi sexual Cross and Self pollination Agents of cross pollination
57. Read NCERT page No 132 to 134 Draw the section of a flower and identify Sepal, Petals, Stamen and Carpel.
58. ? Where are sperms found??
59. Pollens areAnther inside the anther, which contain two male gameteFilament
60. ?? Where is ovum found??
61. Stigma Ovule is inside theStyle Ovary, which contain one female gameteOvary
62. The flower may be unisexual (papaya, watermelon) when it contains either stamens or pistil.
63. The flower may be bisexual (Hibiscus, mustard) when it contains both stamens and Pistil.
64. After the pollen lands on a suitable stigma, a tube grows out of the pollen grain and travels through the style to reach the ovary.
65. Male gametes travel through the tube and reaches to the ovule where female gamete is waiting. Male gamete fuses female gamete to form zygote.
66. Zygote divides several times to form an embryo within the ovule. Embryo gradually develop within the ovule.
67. The ovule develops a tough coat and is gradually converted into a seed. The ovary grows rapidly and ripens to form a fruit. Meanwhile, the petals, sepals, stamens, style and stigma may shrivel and fall off.
68. The seed contains the future plant or embryo which develops into a seedling under appropriate conditions. This process is known as germination.
69. Fusion of male and female gametesFormation and development of zygoteFormation and development of EmbryoGermination/ taking birth of offspring
70. Fertilization, A process in which sperm fuses ovum Post Fertilization Processes, Embryo formation Conversion of ovary and ovule in to fruit and seed Germination of seed
71. Draw a diagram of Germination of pollen on stigma and identify Stigma, Pollen tube, style, ovary, ovule, male and female gametes.
72. In case of animals
73. Increase in height and weight. Growth of pubic hair. Growth of oil gland in face. Self conscious of our own bodies.
74. Development of breast in girls. Menstruation begins in girls. Facial hair in boys. Voices begin to crack in boys. Occasional enlargement and erection of Penis in boys.
75. Thus, the rate of general body growth begins to slow down, reproductive tissues begin to mature.
76. The period of life, when the body undergoes changes, leading to reproductive maturity, is called puberty. Boys and girls become capable of reproduction.
77. Male sex hormone is Testosterone Female sex hormones are Estrogen, Progesterone and Relaxing.
78. Changes in human body during growth Puberty during adolescence
79. Read NCERT Page No. 135-137
80. It is a type of reproduction in which a male gamete fuses a female gamete to produce zygote which develop to form a new individual.
81. Testis which produce Sperms Vas deferens, Urethra and Penis. Seminal vesicles, and Prostate gland
82. These are located outside the abdominal cavity in scrotum because sperm formation requires a lower temperature than the normal body temperature.
83. Testosterone brings about changes in appearance seen in boys at the time of puberty.
84. The urethra thus forms a common passage for both the sperms and urine. Both urine and sperms come out through the muscular penis.
85. Neutralize acidity of the vaginal tractProlonging the lifespan of sperm in the vagina Rich sucrose providesnourishment to the sperm
86. It has long tail that helps them to move towards the female germ-cell. The human sperm cell is haploid, so that its 23 chromosomes (22+ Y) or (22+ X)
87. Testes are the site of sperm formation Testes are the site of Testosterone production Vas deferens connects with urethra Prostate and the seminal vesicle glands secrets alkaline fluid semen Sperms consist of genetic material.
88. Draw the diagram of male reproductive system and identify its parts.
89. Testis which produce Sperms Vas deferens, Urethra and Penis. Seminal vesicles, and Prostate gland
90. It has long tail that helps them to move towards the female germ-cell. The human sperm cell is haploid, so that its 23 chromosomes (22+ Y) or (22+ X)
91. Two Ovaries which produce Ovum Fallopian tubesUterus, cervix and Vagina
92. When a girl is born, the ovaries already contain thousands of immature eggs. On reaching puberty, some of these start maturing. One egg is produced every month by one of the ovaries.
93. To receive a fertilized egg, uterus walls prepares itself by becoming more thicker with rich supply of blood and mucus.
94. The two oviducts unite into an elastic bag-like structure known as the uterus. The uterus opens into the vagina through the cervix.
95. Estrogen brings about changes in appearance seen in boys at the time of puberty.
96. The acidity retards thegrowth of many strains ofdangerous microbesDue to the degradation ofglycogen to the lactic acidby enzymes secreted bythe Döderleins bacillus.
97. The ovum is one of the largest cells in the human body. The human ovum cell is haploid, so that its 23 chromosomes (22 + x)
98. Ovaries are the site of ovum production Ovaries are the site of hormone production Fallopian tubes or oviducts carry ovum to the womb Normal vaginal pH is 3.8 to 4.5, slightly acidic Ovum (Ova) consist of genetic material
99. Draw the diagram of female reproductive system and identify its parts.
100. Testis which produce Sperms Vas deferens, Urethra and Penis. Seminal vesicles, and Prostate gland
101. Two Ovaries which produce Ovum Fallopian tubesUterus, cervix and Vagina
102. To receive and nourish fertilized egg, uterus walls prepares itself by becoming more thicker with rich supply of blood and mucus.
103. It is a type of reproduction in which a male gamete fuses a female gamete to produce zygote which develop to form a new individual.
104. The acrosome of the sperm produces enzymes which allow it to burrow through the outer jelly coat (plasma membrane) of the egg.
105. The nuclei of the sperm and the egg fuse to form a single nucleus, results in the formation of a fertilized egg or zygote.
106. The zygote, gets implanted in the lining of the uterus, and starts dividing to form embryo. Note: It was told that every month uterus wall make itself thicker with blood linings to receive zygote.
107. Placenta is a special tissueembedded in the mothers uterus It connects the embryo to the uterus through villiIt provides O2 & Glucose from the mother to the embryo It removes CO2 & waste from embryo to the mother’s blood
108. The embryo continues to develop in the uterus. It gradually develops the body parts such as hands, legs, head, eyes, ears, etc. this is known as fetus (foetus). It takes 9 months (approximately) to grow.Placenta
109. Surgical birth
110. The sperms enter through the vaginal passage during sexual intercourse. Sperm fuses Ovum to form zygote Zygote develops to form Embryo Embryo gets nutrition from the mother’s blood through placenta and begins to grow. Fetus the developing embryo
111. Explain the formation of zygote with diagram.
112. To receive and nourish fertilized egg, uterus walls prepares itself by becoming more thicker with rich supply of blood and mucus.
113. The acrosome of the sperm produces enzymes which allow it to burrow through the outer jelly coat (plasma membrane) of the egg.
114. The zygote, gets implanted in the lining of the uterus, and starts dividing to form embryo.
115. Placenta is a special tissue embedded in the mothers uterus It connects the embryo to the uterus through villi It provides O2 & Glucose from the mother to the embryo It removes CO2 & waste from embryo to the mother’s bloodPlacenta
116. Surgical birth
117. May not had any sexual intercourse May be Sperms were inactive May be due to some reasons virginal acidity increasedMay be Sperms did not reach to the Ovum
118. Blood lining is not needed any longer. So, the lining slowly breaks and comes out through the vagina as blood and mucous. This cycle takes place roughly every month and is known as menstruation. It usually lasts for about two to eight days.
119. Physical Say “NO” exercise to Drugs Personal Stop Hygiene Adolescent PregnancyNutritional Reproductive Safe sex Needs Health
120. Menstruation in women and menstrual cycle Reproductive health
121. Read NCERT page No. 137-139 Write a short note on reproductive health.
122. The period of life, when the body undergoes changes, leading to reproductive maturity, is called puberty. Boys and girls become capable of reproduction.
123. Reaching the reproductive age at puberty does not mean you have got reproductive maturity. Reproductive maturity comes only when you will become adult.
124. Reproductive maturity means not only development of sex organs, it also indicates physical strength to hold a baby in womb and giving birth of a fit and healthy child.
125. Pregnancy will make major demands on the body and the mind of the woman, and if she is not ready for it, her health will be adversely affected.
126. Blocking Using vas Copper T deferens Changing Blocking hormonal fallopian balance tube Using Contraceptive AbortionCondoms Methods
127. Condoms on the penis or similar coverings worn in the vagina can serve this purpose.
128. so that eggs are not released and fertilization cannot occur. These drugs commonly need to be taken orally as pills. May cause side-effects too.
129. Copper-T are placed in the uterus to prevent pregnancy. May cause side effects due to irritation of the uterus. It does not give protection from sexually transmitted diseases.
130. If the vas deferens in the male is blocked through surgery, sperm transfer will be prevented. May cause infections and other problems if not performed properly.
131. If the fallopian tube in the female is blocked through surgery, the egg will not be able to reach the uterus. May cause infections and other problems if not performed properly. They do not protect against sexually transmitted infections, including HIV/AIDS.
132. Surgery can also be used for removal of unwanted pregnancies. These may be misused by people who do not want a particular child.
133. A Female may not has sexualmaturity but undergoes sexual actPossibility of HIV-AIDS is maximum among the Sex workers Lack of education and unplanned family construction Increasing rate of pollution destroying social balance
134. Various Contraceptive Methods For a healthy society, the female-male sex ratio must be maintained Reasons for adopting various contraceptive Methods