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Gymnosperms: General Characteristics, Classification, and Life Cycle | NEET Biology Notes


Welcome to Chaubey Biology Hub, your premier destination for high-quality, NCERT-aligned medical entrance preparation. We take pride in delivering content that doesn't just mirror textbooks but decodes them. This guide on Gymnosperms: General Characteristics, Classification, and Life Cycle | NEET Biology Notes is meticulously crafted to meet the rigorous standards of the NTA NEET-UG syllabus, focusing exclusively on the core concepts that matter most."

In our previous session, we explored the fascinating world of Pteridophytes: General Characteristics, Classification & MCQ for NEET  in detail. Today, we step further into the evolutionary timeline to discuss a group categorized alongside Angiosperms as 'Higher Plants' — the Gymnosperms.

Table of Contents

  • ​Introduction to Gymnosperms (The "Naked Seed" Plants)
  • ​Key Characteristics of Gymnosperms
  • ​Morphology: Roots, Stem, and Leaves
  • ​Anatomy: Vascular Tissues (Xylem & Phloem)
  • ​Reproduction: Cones and Spores
  • ​Life Cycle and Alternation of Generations
  • ​Economic Importance of Gymnosperms
  • ​Important Examples (Cycas, Pinus, Cedrus)
  • ​MCQs for NEET Revision
 

Introduction
  • Gymnosperms evolved from Pteridophyte. As they are seed bearing plants but their seeds are naked because the ovule are not enclosed by an ovary wall and remain exposed before and after the fertilization.
  • They have vascular tissue for transportation of food and water, their plant body is divided into roots, stems and leaves but they do not  bear flowers. 
  • The term gymnosperm signifies the naked seed because their ovule is not covered by an ovary wall.
  • Gymnosperms are grouped under the  embryophyta. They  are like shrubs , medium height plants and some are long  trees.
  • Sequoia is one of the tallest trees of gymnosperm, called as giant redwood gymnosperm.

Sequoia
  • Gymnosperms can tolerate moist or dry conditions. Gymnosperms evolved  in the Triassic period. Approx 1200 species have been recognized under the gymnosperm. 
💡​​Brain Teasers
Gymnosperms are classified into four types -Cycadophyta, Ginkgophyta, Gnetophyta and coniferophyta. 

General characters of Gymnosperms

Habitat -

  • They are found in colder regions and  They develop needle-like leaves to reduce surface area.
  • In addition to this, the leaves of gymnosperm are well adapted to withstand adverse conditions like temperature , humidity etc.
  • They also have thick cuticles and sunken stomata to reduce the loss of water.

Symbiotic association 

  • Some gymnosperms have fungal symbiotic association in their roots.
  • In Pinus, fungus make association in the root of pinus. This association is called mycorrhiza.
  • In cycas, nitrogen fixing cyanobacteria like Nostoc make association in the root of cycas. Such roots are special in structure  termed Coralloid roots.
    🔥 The sexuality of Gymnosperms is a recurring favorite in the NEET examination. Use these simple memory tricks to never get it wrong again:
    ​1. Pinus (Monoecious)
    ​Male and female cones are present on the same tree.
    ​Memory Trick: P for Pinus, P for Paas-paas (Together).
    ​2. Cycas (Dioecious)
    ​Male and female reproductive structures are located on different (separate) trees.
    ​Memory Trick: C for Cycas, C for Chhod kar alag (Separate/Away).
    ​⚠️ Critical Note: In Cycas, a true 'Female Cone' is absent. Instead, it bears loosely arranged Megasporophylls. This is a high-probability statement for 'Assertion-Reason' type questions!
    Morphological feature

  • The root system in gymnosperm is tap root system because the primary branch of the root has various branches.
💡 Related study about Morphology of Flowering Plants: Root & Stem NCERT Notes + Practice MCQs for NEET
  • The leaves may be simple or compound.
  • The stem is branched like in Pinus or unbranched like in cycas.

Microsporophyll and Megasporophyll 

  • The gymnosperm has a group of two kinds of  leaves called sporophyll.
  • These sporophyll bear sporangia that also produced two kinds of spores - microspore and megaspore.
  • In gymnosperm, small leaves are arranged in the form of microsporophyll which bear microsporangia and produce microspore.
  • The bunch of small leaves in gymnosperm is called female strobili or female cone. 
  • Similarly, Large leaves  are arranged in the form of megasporophyll which bear megasporangia and produce megaspore. 
  • The bunch of large  leaves in gymnosperm is called male strobili or male cone.
Pinus
  • In Pinus, Male and female cones are found in a single plant whereas in Cycles male and female cones are present at different plants.
FeatureCycasPinus
Stem (Tana)Unbranched (Bina shakha wala)Branched (Shakhavala)
Roots (Jadein)Coralloid Roots (Cyanobacteria ke saath)Mycorrhiza (Fungi ke saath)
Leaves (Pattiyan)Pinnate (Badi aur pankh jaisi)Needle-like (Sui jaisi patli)
SexualityDioecious (Male & Female alag ped par)Monoecious (Dono ek hi ped par)
Male GametesMotile (Cilia hote hain)Non-motile

Reproductive structure

  • At microsporophyll, inside the microsporangia, microspores divide and produce male gametophyte or pollen grains.
  • On the other hand, At megasporophyll, inside the megasporangium, an ovule is present and it is surrounded by the protective envelope called integuments.
​🌿 Botany Pro-Tip: > Having trouble with Algae or Gymnosperm examples? Don't miss this high-yield classification guide:
  • Ovule of Gymnosperm has only single integument hence ovule is unitegmic. The cells of integuments are called nucellus.
  • A single cell of nucellus is differentiated and forms a megaspore mother cell.
    🔬 Reproduction & Structure Topics
    00:40 Gymnosperms are Heterosporous (Two types of spores)
    01:55 Understanding Cones or Strobili
    02:22 NEET Hotspot: Monoecious (Pinus) vs Dioecious (Cycas)
    03:49 Male Cone & Microsporophyll structure
    04:46 Microsporangia & Pollen Grains (Reduced Gametophyte)
    05:45 Female Cone & Megasporophyll structure
    06:24 Structure of Gymnosperm Ovule (Megasporangium)
    07:03 Role of Nucellus & Integument in Ovule
    07:15 Presence of Two or more Archegonia

  • These megaspore mother cells divide by meiosis and form four megaspore.
  • Out of four megaspore , one megaspore develops into a female gametophyte. This female gametophyte contains one or two archegonia bearing eggs.
    Feature Gymnosperms Angiosperms
    Reproductive Structure Cones (Strobili) Flowers
    Ovules Naked (No ovary wall) Enclosed within the Ovary
    Pollination Primarily by Wind (Anemophily) Wind, Water, Insects, Animals
    Pollen Landing Directly on the Ovule On the Stigma
    Fertilization Single Fertilization Double Fertilization (Unique)
    Endosperm Haploid (n), formed before fertilization Triploid (3n), formed after fertilization
    Reproduction :

  • In gymnosperm, male gametophyte and female gametophyte are retained within microsporangia and megasporangia respectively.
  • Pollen grains are carried by the wind and reach the ovule.
  • At the ovule, pollen grain germinates the pollen tube and discharges male gamete at the mouth of Archegonia.
  • As a result, fertilization occurs by the fusion of male gamete of pollen grains and egg of archegonia.

📌 Topic Highlights
00:14 - Heterosporous Nature (Intro)
00:51 - Pinus: Monoecious
03:37 - Pollen Grain
04:39 - Ovule Structure
07:30 - Wind Pollination
09:37 - Naked Seeds
  • After fertilization, zygote is changed into embryo and ovule into seed that is without covering. Example- Cycas,Pinus,Ginkgo, Cedrus,Picea etc.

Economic Importance of Gymnosperms 

  • ​Wood Industry: Pines, Firs, and Cedars are the primary source of softwood used for making furniture, paper, and plywood.
  • ​Edible Seeds: The seeds of Pinus gerardiana are known as Chilgoza and are highly nutritious and edible.
  • ​Resins & Oils: Resins obtained from Pinus are used in paints and varnishes. Turpentine oil is also a major product.
  • ​Medicinal Value: The drug Taxol, used in cancer treatment, is extracted from the bark of the Yew tree (Taxus).
  • ​Ornamentals: Cycas and many varieties of Conifers are grown globally for landscaping and decorative purposes.
Dear fellow , with this   post, we have successfully completed our journey through the Plant Kingdom. Now, it's time to dive into the vast and diverse world of the Animal Kingdom.

​To understand this complex group, we will first master the Basis of Classification—the fundamental criteria like body symmetry, levels of organization, and coelom that help us categorize every living creature from sponges to humans.".

🎯 NEET MULTIPLE CHOICE QUESTIONS

🔥 100% CHALLENGE

"Questions yahi se aayega... taiyari jeet ki!"

1. In which group of plants, the ovule are not enclosed by an ovary wall and remain exposed before and after the fertilization.

A. Bryophytes
B. Pteridophytes 
C. Gymnosperms 
D. Angiosperms 
Answer : C  

2. Which of the following statement is  Incorrect.
A. Only Compound leaves are found in Gymnosperm.
B. Tap root are present in Gymnosperms.
C. The leaves of Gymnosperms are well adapted to withstand against temprature, humidity, and wind.
D. Gymnosperms include medium size tree or tall tree and shrub.
Answer: A  

3. How many statement are correct.
1. In Gymnosperms, the seed that form after the fertilization, are naked.
2. The leaves may be simple or compound.
3. In conifers, leaves are pointed or needle like to reduce the surface area.
4. The thick cuticle and sunken stomata help to reduce the water loss.
5. Gymnosperms generally have fibrous root system.
A. Two    B. Three 
C. Four     D. Five 
Answer : C  

4. Which one of the following is giant, redwood tallest Gymnosperms.
A. Sequoia 
B. Ginkgo
C. Cedrus
D. None of the above.
Answer : A  

5. Consider the following statement and select the correct code. 
1. Root of Pinus has fungal association in form of Mycorrhiza.
2. Root of Cycas is Coralloid root because it has symbiotic association with  nitrogen fixing Cyanobacteria.
A. Only  1    B. Only 2
C.Both 1 and 2
D. Neither 1 nor  2
Answer : C  

6. Which one of the following statement is not correct about the Cycas, a Gymnosperms.
A. Male cone and female cone are borne on different tree.
B. Stem is unbranched.
C. The pinnately leaves persist for a fer years.
D. Roots are Coralloid because  Roots have association with nitrogen fixing Cyanobacteria. 
Answer : B  

7. Which of the following statement is  Incorrect with respect to Gymnosperm.
A. They are heterosporous and produce microspore and megaspore with in sporangia.
B. Sporangia are borne on sporophyll which are arranged in form of cone or strobli.
C. Microsporangiate is male cone which bear micosporophyll and microsporangia.
D. Macrosporangiate is female cone which bear megasporophyll and megasporangia without the ovule.
Answer : D 

8.  Consider the following term and arrange them in order.
1. Sporophyll 
2. Cone 
3. Sporangia 
4. Spore 
A.  2 - 1  - 3 - 4
B.  1-  3  - 2 - 4
C.  2 - 1 -  4  - 3
D.  2 - 1 -  3 - 4 
Answer: A  

9. Which of the following statement is correct about the pollen grain or microspore of Gymnosperm.
A. Pollen  grains are highly reduced male gametophyte with limited number of cells.
B.  Microspore are formed with in microsporangia on male cone.
C.  Microspore are developed into male gametophyte.
D. All of the above 
Answer : D 

10.  The stem is branched in
A. Pinus and Cedrus
B. Cycas and Cedrus
C. Cycas and Pinus
D. Cycas, Pinus, Cedrus.
Answer : A 

11. Consider the following statement with respect to the ovule of Gymnosperm and select the correct code:
1.  Ovule or  megasporangi are  born on mega sporophyll.
2. Ovule is composed of cells of nucellus which is protected by envelop.
3. Ovule may be clustered in form of female cone.
4. One of the cell of nucellus is differentiated and act as megaspore mother cell.
A. 1 and  4.
B. 2, 3 and 4
C. 1, 3 and 4
D. 1, 2, 3 and 4
Answer : D  

12. In Gymnosperm, Mega spore mother cell which is diffrentiated from nucellus  divide by meiosis and form 
A. One megaspore
B. Two megaspore
C.Three megaspore
D. Four megaspore.
Answer : D  

13. Out of four megaspore, one megaspore is developed into multicellular gametophyte which bear
A. One archegonium 
B. Two archegonia 
C. Three archegonia
D. Two or MORE archegonia.
Answer: D  

14. How many statement is / are not correct.
1. Main plant body of Gymnosperm is sporophyte and homosporous.
2. Pollen grain are reduced male  gametophyte with limited cell.
3. Female gametophyte is multicellular and retained  within megasporangium
4. Male and  female gametophyte are not independent and free living.
A. One      B. Two 
C. Three   D. Four
Answer: A  

15. Pollen grain are released from microsporangia and reach at mouth of ovule by 
A. Water
B . Insect
C. Wind
D. Insect
Answer : C  

16. Pollen grains are germinated in form of pollen tube at 
A . Archegonia
B. Megasporophyll
C. Ovule
D. Female cone 
Answer: C  

17. Which of the following event does not occur in archegonia of Gynosperm.
A. Pollen tube discharge male gamete  near mouth of archegonia. 
B. Fertilisation takes place in archegonia and zygote is formed.
C. Zygote is developed in to embryo inside the archegonia.
D. Ovule is developed into naked seed.
Answer : D 

18.Consider the following statement and select the correct code:
1. The male and female cone are borne on same tree in cycas.
2. The male and female cone are borne on different  tree in Pinus.
A. Only 1              
B.Only 2 
C. Both 1 and 2
D. Neither 1 nor 2
Answer : D  

19. Identify the following diagram and select the option:

A.Cedrus
B.Pinus
C.Cycas
D. Ginkgo
Answer: D

20. Which Gymnosperm is known as a "Living Fossil"?
A) Pinus
B) Ginkgo biloba
C) Cedrus
D) Cycas
Answer : B

22. In Gymnosperms, the pollination is exclusively carried out by:
A) Water
B) Insects
C) Wind (Anemophily)
D) Animals
Answer : C

23. Which of the following lacks vessels in its xylem?
A) Most Angiosperms
B) Most Gymnosperms (except Gnetum)
C) All Pteridophytes
D) None of the above
Answer : C


 


 















 




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