Download App

Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYSexual Reproduction in Flowering Plants1 Mark
MCQ
For two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Pollen wall is made up of two walls, the intine and the exine.
Reason: Both the walls have depositions of sporopollenin.
  • A
    Both assertion and reason are true, and reason is the correct explanation of assertion.
  • B
    Both assertion and reason are true, but reason is not the correct explanation of assertion.
  • ✓
    Assertion is true, but reason is false.
  • D
    Both assertion and reason are false.
✓

Answer

Correct option: C.
Assertion is true, but reason is false.
The pollen wall comprises two principal layers, the inner one is called intine and the outer exine. The intine is pecto$-$cellulosic in nature, as is the primary wall of the somatic cells. The exine is composed chiefly of a class of material called sporopollenin.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Sexual Reproduction in Flowering Plants→Sexual Reproduction in Flowering Plants — all question types→BIOLOGY STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
 Assertion : Interferons are a type of antibodies produced by body cells infected by bacteria.
Reason: Interferons stimulate inflammation at the site of injury.
→
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : In birds, the chromosome composition of the egg determines the sex.
Reason: Female birds are heterogametic.
→
For question two statements are given $-$ one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Alpha diversity is said to be higher if the dissimilarity between communities is higher.
Reason : Alpha diversity is a measure of diversity between the communities.
→
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Batesian mimicry is a protective mimicry.
Reason: Viceroy butterfly shows Batesian mimicry.
→
For two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Sponge and Delfin are chemical methods of contraception.
Reason: Diaphragms and cervical caps are disposable barrier method of contraception.
→
Directions: In the following questions, the Assertions $(A)$ and Reason$(s) (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Restriction endonucleases recognize short palindromic sequence and cut at specific sites.
Reason: When a restriction endonuclease acts on a palindrome, it cleaves both the strands of $\text{DNA}$ molecule.
→
Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Rhizobium forms nodules on the roots of legume plants.
Reason: Rhizobium fixes atmospheric nitrogen into organic forms which is used by the plant as nutrients.
→
For question two statements are given $-$ one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Many endemic species are seen to flourish in sacred forests.
Reason : Sacred forests are undisturbed forest patches and biodiversity rich areas.
→
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: $R-$type of Pneumococcus is non$-$virulent.
Reason: $R-$type of Pneumococcus can be virulent by having transformation with $S -$type of Pneumococcus.
→
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Microclimate generally differs from the prevailing regional climatic conditions.
Reason: Microclimate represents the climatic conditions that prevail at local scale or in areas of llmited size.
→