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Xam Idea Class 12 Biology Chapter 2 Solutions: Sexual Reproduction In Flowering Plants

Xam Idea Class 12 Biology Solutions for Chapter 2 ‘Sexual Reproduction In Flowering Plants’ is a comprehensive exam practice manual for CBSE Class 12 exams.  These solutions are designed according to the latest CBSE syllabus as well as exam pattern. They will help you to get higher marks in the CBSE as well as other entrance exams like NEET. You will get to revise concepts of pollination, reproductive parts of a plant, structure of flowers, and asexual replication in plants in this chapter.

Xam Idea Class 12 Biology Solutions Sexual Reproduction In Flowering Plants solutions contain 169 questions in total which are divided into four categories. They are very short answer type questions, short answer type questions (type I and II), and long answer type questions respectively. With these questions, you will learn the diagrammatic representation of reproductive parts of a flowering plant, the concept of Megasporangium, Megasporogenesis, pre-fertilization, double fertilization, post-fertilization events, etc.

Xam Idea Solutions for Class 12 Biology Sexual Reproduction In Flowering Plants by Instasolv are built in a concise way to help you grasp every definition in depth. You would also find tidy and labelled drawings across our solutions. Since it is necessary to score a good percentage in board exams, it is not enough to practice only NCERT textbooks. You require effective research materials and solved test problems that have been provided by Instasolv. These Xam Idea solutions will help you revise the chapter quickly. You can rewrite all important problems particularly before the board exams and prepare well.

Important Topics of Xam Idea Class 12 Biology Solutions: Chapter 2 Sexual reproduction In Flowering Plants

Plant Reproduction

  • Plant reproduction is the generation of new progeny in plants that can be produced by asexual reproduction or sexual. 
  • Sexual reproduction yields offspring by amalgamating gametes, leading in offspring that are genetically distinct from the parent.
  • Asexual replication creates new persons through the merging of gametes, genetically similar to the parent plants and with each other, even where mutations arise.

Parts of Plant Reproduction: The packed flower generally consists of:

Pedicel, Sepals, Petals and, Calyx, Stamen (the male reproductive part containing anther & filament)and, Pistil (including stigma, style, & ovary).

Pollination and Its Types

Pollination is an act of transporting pollen grains throughout the anther and stigmatizing the very same flower of a plant as well as the flower of various other plants for the process of reproduction and production of seeds. They are of several types:

  • Geitonogamy – Pollination wherein pollen grains travel from one another over the stigma of different another flower but them of the same plant.
  • Autogamy – Pollination that takes place in the same flower was the pollen grains of one anther get transferred over the stigma of that very same flower.
  • Some natural agents do the work of pollination like wind, water, animals, birds, etc.
  • Heterostyly: This  is the  situation of having unequal male (anther) and female (stigma) reproductive organs;

Cross-pollination: Fertilization by transmitting the pollen through one plant to the next.

  • Self-pollination: Pollination of a flower by flower pollen that contains both stamens as well as the pistil.

  • Mature pollen:
    It comprises two cells along with a  nucleus. They are of two types: Vegetative and Generative
  • Pollen grains were also full of nutrients that are used as pollen tablets for food supplements.

Plant Fertilization is a fusion of male and female gametes (reproductive cells) to create a zygote (fertilized egg cell). This cycle is specific for flowering plants (angiosperms) and seed-bearing plants (gymnosperms).

The fertilization cycle divided into four general stages:

1st stage: Pollution

In particular, male gametes are enclosed in pollen brought by wind, water, or fauna (both insects and animals) to approach female gametes. The pollen is collected on the stigma of the rose, which is part of the pistil (the oblong portion of the flower reaching from the ovary). This is a process called pollination.

2nd Stage:   Germination process

Within the next few minutes, the pollen tubes continue to form or germinate towards the egg. These tubes then provide a way for the sperm that is transported in the pollen to meet the egg.

3rd stage: The Ovule Penetration

The penetration of the pollen tube into the ovule that contains germ cells.

4th stage: Fertilization 

Sperm passes into the channels of the pollen tube and fertilizes the nucleus. Most angiosperms endure double fertilization, in which both the egg as well as the polar nucleus are fertilized in the embryonic sac.

 Stamen, Microsporangium & Pollen Grain :

  • Microsporangium is usually covered by 4 layered membranes, the epidermis, the endothecium, the middle layer as well as the tapetum.
  • Microsporogenesis: The cycle of forming & differentiation of microspores (pollen grains) through microspore mother cells by mitotic cell division is called microsporogenesis.

  • Anther: Four-sided structure comprising 4 microsporangia, two across each lobe.
  • Stamen: long as well as slender stalks named filaments and usually bi-lobed anthers.
  • Microsporangia: It grows further to become a pollen sac containing pollen grains.

Megasporangium (ovule)

  • The ovule is a tiny organ that is connected to the placenta.
  • Nucellus (2n)- A cell mass enclosed within integuments. Has enough nutritional supply.
  • Hilum – The intersection between the ovule as well as the funicular.
  • Funicle – stalk through which the ovule is connected to the placenta.
  • Chalaza – Ovule’s basal part.

Integuments –  Envelopes act as a protection layer. Micropyle- small opening at the tip of the ovule into where the pollen tube enters.

Double Fertilisation

Upon entering one of its synergies, every other pollen grain discharges two male gametes. One male gamete coil with an egg (Syngamy) and another male gamete fuse to two polar nuclei (triple fusion) to generate a triploid primary endosperm nucleus (PEN).

Post-Fertilization

In plants, fertilization is characterized as the merger of male and female gametes into a diploid zygote. Upon fertilization, a sequence of events in the zygote grows into a seed. Let us take a look at the post-fertilization, endosperm & embryo forming cycle.

When fertilization happens, there occur several modifications in the composition of the plant. As a result, the ovaries become the fruit. As a result, the ovule becomes seed alongside the integument of the ovules generated as the outer covering of the seed. The calyx sepals and the corolla petals start dropping off.

Artificial Hybridization

Crossover of the different varieties of the species-hybrid individual with the desirable parent plant’s characteristics.

Bagging

Lined flower-bag made of butter that prevents stigma damage from unnecessary pollen.

Discussion of Exercises for Xam Idea Class 12 Biology Solutions Chapter 2: Sexual Reproduction In Flowering Plants

Xam Idea Class 12 Biology Solutions for Chapter 2 Sexual Reproduction In Flowering Plants contains 169 questions in total which are divided into four categories and further into PYQ (past years questions) and OIQ (objective inventory questionnaires).

Very Short Answer Questions

  • It comprises a total of 62 problems out of which 30 problems placed under the PYQ segment and the rest 32 problems placed under the OIQ segment. These questions are normally straightforward and simple to answer.
  • This section is based on vital terms like polyembryonic, parthenocarpy, characteristics of pollen grains, pollination, and angiosperm.

Short Answer Questions Type – I

  • This section essentially contains 48 questions which are categorized into 39 PYQ and rest 9 problems within the OIQ segment.  You are required to present a neat diagrammatic representation to support your answers whenever required.
  • The questions are based on phenomena of microsporangium of a mature anther, parthenogenesis, parthenocarpy, filiform apparatus, and differences between dicot monocot embryos.

Short Answer Questions Type – II

  • This section essentially contains 42 questions that are categorized into 23 PYQ and rest 19 problems within the OIQ segment.
  • Here you need to analyze pollen grains properties that help in fossilization.

Long Answer Type Questions

  • This section contains 17 questions that are segmented into 9 questions in PYQ and 8 problems within the OIQ segment.
  • These are diagrammatic questions based on different anther layers, pollen pistil interactions, anatropous ovule, the component of embryo sac after fertilization, and double fertilization.

 Why Use for Xam Idea Class 12 Biology Solutions Chapter 2: Sexual reproduction In Flowering Plants by Instasolv?

  • These Xam Idea solutions will clear all your concerns and confusion at a single platform alongside will provide you with the most vital study material in a catalogued format.
  • The solutions prepared by our subject matter experts are compatible with all the recommendations set down by the CBSE.
  • The answers are offered in a student-friendly vocabulary and are simple to comprehend.
  • These approaches will help you in preparing chapters with thorough updates for upcoming board exams.