What is bagging technique? How is it useful in a plant breeding programme?
Solution and Explanation
Various artificial hybridization techniques (under various crop improvement programmes) involve the removal of the anther from bisexual flowers without affecting the female reproductive part (pistil) through the process of emasculation. Then, these emasculated flowers are wrapped in bags to prevent pollination by unwanted pollen grains. This process is called bagging.
This technique is an important part of the plant breeding programme as it ensures that pollen grains of only desirable plants are used for fertilization of the stigma to develop the desired plant variety.
Top Questions on sexual reproduction in flowering plants
Student to attempt either option (A) or (B).
(A)
(i) Describe the process of megasporogenesis in an angiosperm.
(ii) Draw a diagram of a mature embryo sac of the angiosperm. Label its any four parts.
OR
(B) The reproductive cycle in the female primates is called menstrual cycle. The first menstruation begins at puberty.
Answer the following questions:
(i) Name the four phases of menstrual cycle in a proper sequence.
(ii) How long does the menstrual phase last in a menstrual cycle?
(iii) When and why hormones estrogen and progesterone reach their peak levels respectively, in the menstrual cycle?
(iv) Give the significance of LH surge.- CBSE CLASS XII - 2025
- Biology
- sexual reproduction in flowering plants
Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.
Note : All plants belong to the same species. No pollen tube growth/inhibition of pollen germination on stigma. Pollen germination on stigma.- [(a)] Name and define the outbreeding device described in the above table.
- [(b)] Explain what would have been the disadvantage to the plant in the absence of the given strategy.
- CBSE CLASS XII - 2025
- Biology
- sexual reproduction in flowering plants
Answer the following questions:
[(i)] Explain the structure of a mature embryo sac of a typical flowering plant.
[(ii)] How is triple fusion achieved in these plants?
OR
[(i)] Describe the changes in the ovary and the uterus as induced by the changes in the level of pituitary and ovarian hormones during menstrual cycle in a human female.
- CBSE CLASS XII - 2025
- Biology
- sexual reproduction in flowering plants
- What are the significances of double fertilization?
- Maharashtra Class XII - 2025
- Biology
- sexual reproduction in flowering plants
- How many meiotic divisions are required for the formation of 300 seeds in angiosperm?
- Maharashtra Class XII - 2025
- Biology
- sexual reproduction in flowering plants
Questions Asked in CBSE CLASS XII exam
- A convex lens of focal length \( f = 15\,cm \) forms a real image of a 6 cm tall object placed at 30 cm. Find the position, nature, and height of the image.
- The electric field at a point in a region is given by \( \vec{E} = \alpha \frac{\hat{r}}{r^3} \), where \( \alpha \) is a constant and \( r \) is the distance of the point from the origin. The magnitude of potential of the point is:
- CBSE CLASS XII - 2025
- Electrostatics
- Define a wavefront. An incident plane wave falls on a convex lens and gets refracted through it. Draw a diagram to show the incident and refracted wavefront.
- CBSE CLASS XII - 2025
- Wave Optics
- If a natural population of 60 individuals is in Hardy-Weinberg equilibrium for a gene with two alleles B and b, with the gene frequency of allele B of 0.7, the genotype frequency of Bb will be:
- CBSE CLASS XII - 2025
- evolution
- If \( \overrightarrow{a} + \overrightarrow{b} + \overrightarrow{c} = 0 \), \( |\overrightarrow{a}| = \sqrt{37} \), \( |\overrightarrow{b}| = 3 \), and \( |\overrightarrow{c}| = 4 \), then the angle between \( \overrightarrow{b} \) and \( \overrightarrow{c} \) is:
Concepts Used:
Pre-fertilization events - Monoecious Plant
Fertilization in plants may be a process during which they undergo amphimixis in consequence of pollination and germination. During a physicochemical process, the male gametes (known as pollen) infusion with the feminine gametes (known as ovum) forms diploid zygote after carpal pollinates. The whole process happens in a zygote which later germinates into a seed. During the method, what happens is male gametes are transferred into female reproductive organs through pollinators (butterflies, birds, honey bees, bats, and flower beetles). This leads to an embryo being formed during a seed. Flowers are the reproductive organs of angiosperms and reproduce in a completely different method.
Read More: Flower Structure
The two important pre-fertilization procedures are gametogenesis and gamete transfer. The female and male reproductive forms in flowers are the androecium and the gynoecium which distinguishes and goes through development.
"Mono" means single so a monoecious plant is one that bears both male and female sex organs on same plant. The monoecious plant can produce bisexual flowers or unisexual flowers. A dioecious plant is one that bears both male and female sex organs on different plants.
Read Further: Sexual Reproduction in Flowering Plants