Sexual Reproduction in Flowering Plants
Quiz-16
Dear Readers,
NEET is the most famous and important medical entrance examination held in our country. This exam is an objective type, an offline test which includes 4 sections namely– Physics, Chemistry, Botany, and Zoology. The maximum marks that can be scored are 720 marks and have 180 questions.
About half of the paper consists of questions from Biology, as the NEET exam essentially focuses on capacitating students to go for seats in medical courses. One of the most significant and crucial sections in the NEET exam is of Biology. It comprises of theories, descriptions, discoveries, diagrams, definitions, explanations of differences, and relations. The majority of the topics covered in the NEET syllabus are from the NCERT syllabus of Class 11 & 12 and other related sources become part of the rest of the syllabus.
Clear Exam curates a list of articles selected by professionals who recommend the highly vital topics for NEET exams. The table below takes you directly to the respective topic where the in-depth article and the MCQs are available for an easy and productive learning experience. Prior to solving NEET question papers or practicing mock tests, you must ensure to study the basic concepts in NEET and practice a few sample questions related to this exam. Students will be covered for all their studies as the topics are available from basics to even the most advanced.
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Q1. Diagram showing discharge of gametes in the egg apparatus. Identify A,B and C
Solution
Discharge of male gametes into a synergid and the movements of the sperms, one into the egg the other into the central cell.
Q2.Micropyle is formed by
Solution
Absence of integuments. Micropyle is found is both seed and ovule. In seed it is the pore through which water goes inside during germination. In ovule the absense of integuments form micropyle.
Absence of integuments. Micropyle is found is both seed and ovule. In seed it is the pore through which water goes inside during germination. In ovule the absense of integuments form micropyle.
Q3. Double fertilization was discovered by
Solution
Double fertilization was discovered by Nawaschin and Strasburger.
Double fertilization was discovered by Nawaschin and Strasburger.
Q4. Cleistogamous flowers
Solution
Never open. Chasmogamy is the type of autofertilisation (self-fertilisation) in which both male and female gametes present on same flower but pistil and stamen have special adaptation like bending length, etc., so that fertilization takes place. They are open flower not closed like cleistogamous flowers.
Never open. Chasmogamy is the type of autofertilisation (self-fertilisation) in which both male and female gametes present on same flower but pistil and stamen have special adaptation like bending length, etc., so that fertilization takes place. They are open flower not closed like cleistogamous flowers.
Q5.Coleorhiza is
Solution
Lower end of embryonal axis in monocot.Embryos of monocotyledons possess only one cotyledon. In the grass family the cotyledon is called scutellum that is situated toward the one side (lateral) of the embryonal axis. At its lower end, the embryonal axis has the radical and root cap enclosed in an undifferentiated sheath called coleorhiza.
Lower end of embryonal axis in monocot.Embryos of monocotyledons possess only one cotyledon. In the grass family the cotyledon is called scutellum that is situated toward the one side (lateral) of the embryonal axis. At its lower end, the embryonal axis has the radical and root cap enclosed in an undifferentiated sheath called coleorhiza.
The portion of the embryonal axis above the level of attachment of scutellum is epicotyl. Epicotyl has a shoot apex and few leaf primordial enclosed in hallow structure the coleoptile.
Q6. Approximate diameter of pollen grain is
Solution
Pollen grain are generally 25-50 μm in diameter. Pollen grains have two main layers
Pollen grain are generally 25-50 μm in diameter. Pollen grains have two main layers
(i) Outer Layer It is also called exine. It is made up of sporopollenin. It is hard and protective in nature. Due to sporopollenin pollen can with stand extreme temperatures.
(ii) Inner layer It is also called intine. It is made up of cellulose and pectin. It is very thin as compared to the outer layer.
Q7. Ubisch bodies are secreted by
Solution
Tapetum is the innermost layer of another wall and is generally comprised only a single layer of nutritive cells. It also forms Ubisch bodies which help in the formation of exine of pollen grains.
Tapetum is the innermost layer of another wall and is generally comprised only a single layer of nutritive cells. It also forms Ubisch bodies which help in the formation of exine of pollen grains.
Q8. An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is
Solution
In hemianatropous type, the ovule becomes curved and nucellus and embryo sac lies at right angles to the funicle, e.g., Ranunculaceae, while in campylotropous, the micropyle is directed forwards chalaza. Chalaza lies at right angle to funicle, e.g., Leguminosae.
In hemianatropous type, the ovule becomes curved and nucellus and embryo sac lies at right angles to the funicle, e.g., Ranunculaceae, while in campylotropous, the micropyle is directed forwards chalaza. Chalaza lies at right angle to funicle, e.g., Leguminosae.
Q9. In some organisms, karyokinesis is not followed by cytokinesis as a result of which, multinucleate condition arises leading to the formation of syncytium. The perfect example for this is
Solution
Coconut endosperm is unique because of its early liquid syncytial stages, which forms a hard matured kernel at later stages of fruit development.
Coconut endosperm is unique because of its early liquid syncytial stages, which forms a hard matured kernel at later stages of fruit development.
Q10. Identify A and E in the diagram given below 
Solution
Development of Female Gametophyte
Development of Female Gametophyte
(i) Megaspore mother cell undergoes the reductional/meiotic division that give rise to four megaspores.
(ii) Three of them die (in majority of plants) only one remains viable. This method of embryo sac formation is called monosporic development.
(iii) The nucleus of the functional megaspore divides mitotically to form two nuclei, which move to the opposite poles forming two nucleate embryo sac.
(iv) Two more sequential mitotic nuclear divisions results in the formation of
four nucleate and later 8 nucleate stages of embryo sac.
(v) After the 8 nucleate stage cell walls are laid down leading to the organization of typical female gametophyte.
