Q1:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Clones are offspring of an organism formed by asexual reproduction.
Reason : Clones have exact copies of DNA as their parents.
Explanation
Clones are defined as a group of morphologically and genetically identical individuals. In the process of asexual reproduction,only one parent is involved to produce morphologically and genetically similar off spring from parents and are thus called clones
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Q2:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Colonies of yeast multiply in sugar solution.
Reason : Sugar is made of sucrose which provides energy for sustaining all life activities
Explanation
Yeasts are eukaryotic microorganisms, classified in the kingdom Fungi. Yeasts are chemoorganotrophs and they use organic compounds as a source of energy. Carbon is obtained through various sugars. Yeasts can metabolize sugars as they ferment sugar resulting in the formation of ethanol. So, sugar provides energy to yeasts, which helps to carry out various life processes.
So, the correct answer is 'Sugar provides energy for sustaining all life activities in yeasts'.
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Q3:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Asexual reproduction is a primitive type of reproduction.
Reason : Asexual reproduction involves only mitotic cell division.
Explanation
Organisms reproduce for perpetuation of species because individuals have a limited life span. Organisms may reproduce sexually as well as asexually. The sexual reproduction involves formation of haploid gametes through the process of reduction division or meiosis. The haploid gametes fuse during fertilization to form diploid zygote. Thus, restoring the normal ploidy. The asexual reproduction does not involves gamete formation through meiosis or their fertilization. The vegetative propagation in plants is a type of asexual reproduction in which plant body is propagated directly from some vegetative part of adult plant.
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Q4:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Spores are unicellular bodies.
Reason : The parent body simply breaks up into smaller pieces on maturation
Explanation
Spore formation - Spore formation is generally seen in bacteria and most fungi. Spores are unicellular bodies, formed by the parent organism to carry out reproduction. If environmental conditions are suitable, the spore will develop into a new individual. Spores come in a wide variety of forms and are produced and dispersed in many different ways. Spores are very effective, because they are small and light, and so can be carried by wind, water or animals; so they can travel far away from the parent, perhaps to better conditions.
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Q5:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : At puberty, in boys, the voice begins to crack and thick hair grows on the face.
Reason : At puberty, there is decreased secretion of testosterone in boys.
Explanation
Puberty in boys is regulated by male sex hormone called testosterone, which are secreted by testes. In puberty, secondary sexual characteristics like growth of hair on face, chest, broadening of shoulders and deepening of voice occurs.
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Q6:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Plasmodium reproduces by multiple fission.
Reason : Multiple fission is a type of asexual reproduction.
Explanation
Multiple fission is the process of asexual reproduction in which instead of 2 daughter cells, many daughter cells are produced from the parent cell. In this, the nucleus undergoes repeated division to produce a large number of nuclei. Each nucleus along with a little bit of cytoplasm forms a membrane around it. All the daughter cells are equal sized and are similar. Plasmodium, true slime molds (Myxomycetes) exhibit this type of asexual reproduction.
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Q7:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Holoblastic cleavage with almost equal sized blastomeres is a characteristic of placental animals.
Reason : Eggs of most mammals, including humans, are of centrolecithal type.
Explanation
Holoblastic type of cleavage with equal sized blastomeres is commonly seen in eggs containing moderate to sparse amount of yolk. It is characteristic of mammals.
Reason is incorrect as eggs of most mammals including humans are of alecithal, meaning negligible amount of yolk. Centrolecithal eggs are found in insects, where yolk is present at the center of the egg with cytoplasm around it.
Therefore, the correct answer is option C.
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Q8:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Asexual reproduction is also called blastogenesis.
Reason : In asexual reproduction, their is no formation and fusion of gametes.
Explanation
The process of asexual reproduction with the help of any part of the body not inclusive of the reproductive parts is known as blastogenesis. Asexual reproduction is the method in which single parent gives rise to the offspring. There is no formation or fusion of the gametes because the single parent is involved.
Thus, the correct answer is option B.
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Q9:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Urethra in human male acts as urogenital canal.
Reason : Urethra carries only urine while sperms are carried by vasa deferentia only.
Explanation
The urethra is the canal through which urine is discharged from the bladder in most mammals and through which semen ( the fluid like discharge containing male gametes, sperms) is also discharged in the males and hence, it is called urogenital tract. So, urethra carries both urine and sperms.
Thus, the correct answer is option C.
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Q10:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Pollen grains from the carpel stick to the stigma of stamen.
Reason : The fertilised egg cells grow inside the ovules and become seeds.
Explanation
The pollen grain is transferred from the anther to the stigma of the carpel. The stigma is the receptive surface of the female part of the flower.
On the other hand, the ovary often supports a long style, topped by a stigma. The mature ovary is a fruit, and the mature ovule is a seed. The stigma is the part of the pistil where pollen germinates.
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Q11:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Unisexual flowers have separate male and female flowers whereas a typical monocot embryo comprises an embryonal axis with single cotyledon.
Reason : Cucumber, pumpkin and water melon are example of unisexual flowers.
Explanation
Unisexual flowers have separate male and female flowers. The example includes cucumber, pumpkin and watermelon.
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Q12:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : In human male, there are perianal glands near the anus.
Reason : Perianal glands secrete sex-attractant pheromone which initiates sexual desire in human female.
Explanation
Perineal gland are found in rabbit but not in human beings. These are a pair of dark elongated scent glands lying behind the cowper's glands. These are sex attractant secreting glands, its smell serves as sex attractant for the female.
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Q13:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Vasectomy is a surgical method or birth control.
Reason : In vasectomy, a small portion of the oviduct is cut or tied properly.
Explanation
Vasectomy is a surgical method or birth control. in which a small portion of the sperm duct is cut or tied properly.
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Q14:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion : Vagina is also called the birth canal.
Reason : During birth, the baby passes through the vagina.
Explanation
Vagina is called the birth canal, because the baby passes through the vagina during birth.
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Q15:
Question for Assertion & Reason Type Questions: How do Organisms Reproduce?
Try yourself:Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:
Assertion : In human male, testes are extra-abdominai which are present inside scrotum.
Reason : Scrotum has a relatively lower temperature needed for the production and storage of sperms.
Explanation
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
Explanation: Formation of sperms needs lower temperature than the normal body temperature. Hence, testes lie outside the body cavity in the scrotum.
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