A typical microsporangium of angiosperms is generally surrounded by four wall layers - epidermis, endothecium, middle layers and tapetum.
The outer three wall layers perform the function of protection and help in dehiscence of anther to release the pollen.
- If both assertion and reason are true and reason is the correct explanation of assertion
- If both assertion and reason are true but reason is not the correct explanation of assertion
- If assertion is true but reason is false
- If both assertion and reason are false
The Correct Option is B
Solution and Explanation
Top Questions on 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
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
- Select the statements that are true for the seed of angiosperm from the given options:
(i) Non-albuminous seeds have no residual endosperm.
(ii) Residual, persistent nucellus in wheat is known as perisperm.
(iii) Integuments of ovules harden as tough protective seed coat.
(iv) Metabolic activity of the embryo slows down in dormancy.
Choose the correct option:- CBSE CLASS XII - 2025
- Biology
- sexual reproduction in flowering plants
- Unisexuality of flowers prevents which process?
- CBSE CLASS XII - 2025
- Biology
- 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
Notes on sexual reproduction in flowering plants
Concepts Used:
Sexual Reproduction in Flowering Plants
Sexual reproduction in flowering plants takes place or happens when the production of a new organism occurs from two parents by making use of their gametes or sex cells. Both sexual and asexual reproduction can be found in plants. Nearly all flowering plants reproduce sexually. Flowers play a captious role in the process as it carries both the male and female reproductive parts commonly known as androecium and gynoecium respectively.
An individual flower comprises the following parts -
- Pedicle
- Calyx
- Petals
- Sepals
- Stamen
- Pistil
- Receptacle