Biology MCQs for Class 12 with Answers Chapter 1 (Reproduction in Lower and Higher Plants)



Q. 1 Multiple choice questions.
1. Insect pollinated flowers usually posses
................
    a. Sticky pollens with rough surface
    b. Large quantities of pollens
    c. Dry pollens with smooth surface
    d. Light coloured pollens
Ans: a ( Explanation : Insect-pollinated flowers usually possess sticky and heavy pollens with a rough surface that allow them to stick to insects easily. The pollen grains are also in small quantities, because it is very likely that insects will enter another flower, and the pollen grains would have a higher chance of landing on the stigma. That's why there is no need of pollen grains in large quantities. 


2. In ovule, meiosis occurs in ..........
    a. Integument
    b. Nucellus
    c. Megaspore
    d. Megaspore mother cell
Answer : d  ( Explanation : In the ovule
Megaspore mother cell / megasporocyte which divides by meiosis to form four haploid megaspores.
Thus, in ovule meiosis occurs in megasporocyte / Megaspore Mother Cell


3. The ploidy level is NOT the same in ......
    a. Integuments and nucellus
    b. Root tip and shoot tip
    c. Secondary nucleus and endosperm
    d. Antipodals and synergids
Answer : c ( Explanation : Integuguments and nucellus carry  2n respectively. Root tip & shoot tip also carry 2n respectively. Antipodals & synergids carry only n respectively. While secondary nucleus carry 2n & endosperm carry 3n. That's why the ploidy level is NOT same in secondary nucleus and endosperm.


4. Which of the following types require pollinator but result is genetically similar to autogamy?
     a. Geitonogamy
     b. Xenogamy
     c. Apogamy
     d. Cleistogamy
Answer : a ( Explanation : Transfer of pollen from an anther of one flower to a stigma of another flower on the same plant is called as geitonogamy. Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the same plant. 


5. If diploid chromosome number in a flowering plant is 12, then which one of the following will have 6 chromosomes?
    a. Endosperm
    b. Leaf cells
    c. Cotyledons
    d. Synergids

Answer : d ( Explanation : Synergids are formed by megaspore which is a haploid structure. Thus synergids are haploid and possess 6 chromosomes.
So, the correct answer is 'synergids')


6. In angiosperms, endosperm is formed by/ due to ..........
    a. Free nuclear divisions of megaspore
    b. polar nuclei
    c. polar nuclei and male gamete
    d. synergids and male gamete
Answer : c ( Explanation : 
Endosperm is formed when the two sperm nuclei inside a pollen grain reach the interior of a female gametophyte and one the sperm is fused with polar nuclei and forms Endosperm. That's why the correct answer is 'c' polar nuclei and male gamete.


7. Point out the odd one ...........
    a. Nucellus
    b. Embryo sac
    c. Micropyle
    d. Pollen grain
Answer : d.  ( Explanation : Pollen grain is odd one among all the other three.
Pollen grain in a male gametophytic structure. Whereas all the other three are found inside ovule, (nucellus, micropyle and embryo sac. )