Let’s Revise the Topics Covered under this Chapter ( How do Organism Reproduce): [For detailed Understanding, visit our NOTES by CLICK HERE ]
Test your understanding with these important case-study questions designed for Class 10 Science Chapter 7 – How do Organisms Reproduce. Practice them carefully to strengthen your concepts and secure full marks in your Board Exam.
CASE STUDY QUESTIONS
CASE STUDY 1 — IVF Technology
A couple unable to conceive undergoes IVF where eggs are extracted from the mother and sperms from the father. Fertilisation occurs in a lab and the embryo is transferred into the uterus.
Q1. Why is fertilisation outside the body still considered sexual reproduction?
Answer: Because it still involves fusion of male and female gametes, though outside the body.
Q2. What ensures that the embryo produced through IVF is genetically related to parents?
Answer: Because the embryo forms from mother’s ovum and father’s sperm, transferring their DNA.
Q3. Why is controlled temperature important during IVF fertilisation?
Answer: Gamete fusion requires optimal temperature for enzyme-based reactions, ensuring embryo survival.
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CASE STUDY 2 — Flower Pollination Experiment
A student removes anthers from a flower and covers it with a plastic bag. He observes no seed formation.
Q1. Why were seeds not formed?
Answer: Because pollination could not occur due to removal of anthers and blocking external pollen.
Q2. Which process was prevented: fertilisation or germination? Why?
Answer: Fertilisation, because no pollen reached stigma, so gamete fusion didn’t happen.
Q3. What is the role of the pollen tube which was missing here?
Answer: It carries male gametes to ovule enabling fertilisation.
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CASE STUDY 3 — Variation During Meiosis
During a chromosome study, students observe that gametes produced show mixed genetic material.
Q1. Where does this mixing occur?
Answer: During crossing over in meiosis.
Q2. Why is this mixing beneficial?
Answer: Produces variation, improving species’ adaptability.
Q3. Why do somatic cells not show this variation?
Answer: They undergo mitosis, which produces identical cells.
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CASE STUDY 4 — Cloning of Dolly
Scientists cloned Dolly the sheep through somatic cell nuclear transfer.
Q1. Was Dolly genetically identical to biological mother or surrogate?
Answer: Identical to biological mother, whose nucleus was used.
Q2. Why is cloning considered asexual reproduction?
Answer: Because no gamete fusion occurs.
Q3. State one drawback of cloning.
Answer: Reduced genetic diversity, leading to weak immunity.
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CASE STUDY 5 — Sperms Under the Microscope
A lab observed sperm samples from two individuals; one sample had very low motility.
Q1. Why is motility important?
Answer: Sperms must swim to reach ovum for fertilisation.
Q2. Which cell structure helps sperms move?
Answer: Flagellum (tail).
Q3. Low motility leads to which reproductive problem?
Answer: Reduced chances of natural fertilisation.
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Explore Class 10 Science Chapter-7 Reproduction Important Question Answers – CLICK HERE
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CASE STUDY 6 — Regeneration in Planaria
Students cut planaria into three pieces and observed them grow into new organisms.
Q1. Why can planaria regenerate so effectively?
Answer: They have large number of stem-like cells.
Q2. Is this sexual or asexual reproduction?
Answer: Asexual reproduction.
Q3. Why can’t humans regenerate like this?
Answer: Humans have complex organ systems and lack regenerative cells.
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CASE STUDY 7 — Hormonal Imbalance
A teenage girl has irregular menstrual cycles due to hormonal imbalance.
Q1. Which two hormones mainly regulate menstrual cycle?
Answer: Estrogen and progesterone.
Q2. How does their imbalance affect cycle?
Answer: Causes irregular ovulation and fluctuating uterine lining development.
Q3. Which organ secretes these hormones?
Answer: Ovaries.
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CASE STUDY 8 — Hydra Budding
During an experiment, a student observes multiple buds growing on hydra.
Q1. Why does hydra produce multiple buds under favourable conditions?
Answer: High nutrition increases cell division, forming many buds.
Q2. Is genetic variation produced here?
Answer: No, offspring are genetically identical.
Q3. Why does budding increase population rapidly?
Answer: Process is fast, simple, and energy-efficient.
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CASE STUDY 9 — Asexual Reproduction in Yeast
A biology team is culturing yeast in a sugar-rich solution. After 24 hours, they observe multiple small outgrowths on the yeast cells. They also note that the new cells show a faster growth rate due to continuous nutrient supply.
Q1. Identify the mode of reproduction shown and state why it is suitable for yeast.
Answer: Budding; because yeast can rapidly divide in nutrient-rich environments.
Q2. Why do the newly formed buds detach only after reaching a certain size?
Answer: They must develop essential organelles and metabolic capability before surviving independently.
Q3. Will this method lead to genetic variation? Why or why not?
Answer: No, because DNA copying is identical without gamete fusion.
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CASE STUDY 10 — Fallopian Tube Blockage
A woman has blocked fallopian tubes due to infection. Her ovulation is normal, and the uterus is healthy, but pregnancy is not occurring.
Q1. Which step is directly affected due to blocked tubes?
Answer: Fertilisation, because sperms cannot reach the ovum.
Q2. Why does normal ovulation still not guarantee pregnancy?
Answer: Released ovum cannot meet sperm, so zygote formation doesn’t occur.
Q3. Suggest one advanced method that can help this couple conceive.
Answer: IVF (In Vitro Fertilisation).
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Click the link below to explore more chapter-wise important questions
Class 10 Important Question Answers
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CASE STUDY 11 — Seedless Fruit Production
Farmers grow seedless grapes using a technique where stems of parent plants are cut and planted in soil, producing identical offspring.
Q1. Which method is being used and why does it produce seedless plants?
Answer: Vegetative propagation; because no fertilisation occurs, so no seeds form.
Q2. Why do offspring remain identical in this method?
Answer: They arise from somatic cells, not gametes, so variation is absent.
Q3. Give one advantage and one disadvantage of this method.
Answer:
- Advantage: Fast and reliable reproduction.
- Disadvantage: No variation → low disease resistance.
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CASE STUDY 12 — DNA Copying Error in Reproduction
During an experiment, students observe offspring of bacteria grown over many generations. Although reproduction is asexual, small differences occur in some cells due to DNA copying errors.
Q1. What do these small differences represent?
Answer: Variations arising from random DNA mutations.
Q2. Why are such variations beneficial?
Answer: They help bacteria survive in changing environments (e.g., antibiotic resistance).
Q3. Would sexual reproduction introduce more variation? Why?
Answer: Yes; because gamete fusion mixes genetic materials from two parents
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CASE STUDY 13 — Embryo Development in Birds
A researcher studies chick development. The zygote forms in the oviduct and is then surrounded by a hard shell. The embryo develops outside the body but relies entirely on the stored yolk.
Q1. Why does embryo development occur outside the body in birds?
Answer: Hard eggs provide protection and nutrients needed for complete development.
Q2. What is the role of the yolk?
Answer: Supplies nutrition for growth throughout embryonic stages.
Q3. How does this development differ from human embryo development?
Answer: Human embryos develop inside the uterus and receive nutrients through placenta.
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CASE STUDY 14 — Planarian Regeneration Failure
A teacher cuts planaria into pieces for regeneration study. However, one piece fails to develop due to damaged cells in its central region.
Q1. Which cells are responsible for regeneration, and why did regeneration fail here?
Answer: Neoblasts (stem-like cells); regeneration failed because these cells were damaged.
Q2. Is regeneration a type of sexual or asexual reproduction?
Answer: Asexual reproduction.
Q3. Why is regeneration not possible in higher animals?
Answer: Due to complex organ systems lacking high regenerative cell density.
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CASE STUDY 15 — Menstrual Health and Iron Deficiency
A teenage girl experiences heavy bleeding during menstruation and develops iron deficiency.
Q1. Why can heavy bleeding lead to iron deficiency?
Answer: Excessive blood loss reduces iron-containing haemoglobin.
Q2. Which hormone imbalance may cause heavy menstrual flow?
Answer: Estrogen-progesterone imbalance.
Q3. Which organ regulates this cycle?
Answer: Ovaries (through hormones).
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CASE STUDY 16 — Artificial Pollination in Crops
Scientists hand-pollinate flowers in a greenhouse by collecting pollen and transferring it to stigmas manually.
Q1. Why is hand pollination needed here?
Answer: To ensure controlled cross-pollination for better crop traits.
Q2. Which structure receives pollen during this process?
Answer: Stigma.
Q3. What happens immediately after pollen lands on the stigma?
Answer: Pollen grain germinates and forms a pollen tube.
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Complete and easy NOTES of Class 10 Science Chapter 7 (How Do Organisms Reproduce?) — Read here
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