In grasses what happens in micro spore mother cell for the formation of mature pollen grains
- One meiotic and two mitotic divisions
- One meiotic & one mitotic divisions
- One meiotic division
- One mitotic division
The Correct Option is A
Solution and Explanation
Top Questions on sexual reproduction in flowering plants
- (a) A bilobed dithecous anther has 200 microspore mother cells per microsporangium. How many male gametophytes can be produced by this anther?
(b) Write the composition of intine and exine layers of a pollen grain.
- 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
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
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
Questions Asked in NEET exam
- A microscope has an objective of focal length \(f_o = 2\) cm and an eyepiece of focal length \(f_e = 4\) cm. The tube length of the microscope is \(L = 40\) cm. If the distance of distinct vision of eye is \(D = 25\) cm, the magnification in the microscope is:
- NEET (UG) - 2025
- Optical Instruments
- Which one of the following is an example of ex-situ conservation?
- NEET (UG) - 2025
- Ex-Situ Conservation
- Which one of the following compounds can exist as cis-trans isomers?
- NEET (UG) - 2025
- Organic Chemistry
- Who proposed that the genetic code for amino acids should be made up of three nucleotides?
- NEET (UG) - 2025
- Molecular Biology
- An electron (mass \(9 \times 10^{-31}\) kg and charge \(1.6 \times 10^{-19}\) C) moving with speed \(c/100\) (\(c\) = speed of light) is injected into a magnetic field of magnitude \(9 \times 10^{-4}\) T perpendicular to its direction of motion. We wish to apply a uniform electric field \( \vec{E} \) together with the magnetic field so that the electron does not deflect from its path. (speed of light \(c = 3 \times 10^8\) m/s):
- NEET (UG) - 2025
- Electric Field
Concepts Used:
Fertilisation
Fertilization happens when a sperm fuses with the female act during sexual intercourse and further forms an egg that gets implanted in the uterus of the female. The sperm goes through the fallopian tube and penetrates the zona pellucida layer of the ovum (female egg) and then fuses with it which forms a zygote (fertilized egg). Thousand of sperms are generated in a male body to compensate for the ones unfit and non-motile ones. Once the zygote is created or formed, it gets implanted in the uterus and further growth starts taking place when cells start dividing and forming tissues, and tissues further form organs which result in the formation of an organ system, eventually or in time turning into an organism.