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Gymnosperms

Description: gymnosperms cycas pinus GymnospermsGymnosperms
Number of Questions: 15
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Tags: gymnosperms cycas pinus Gymnosperms
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What is the nature of coralloid roots?

  1. Aerial

  2. Phototropic

  3. Positively geotropic

  4. Negatively geotropic

  5. Apogeotropic


Correct Option: E
Explanation:

Coralloid roots are apogeotropic, that is they grow upward toward the surface of the soil, instead of downward into its depths. When the roots grow upwards it is called as apogeotropism and negatively geotropism is specifically used for stems and not for roots.

Vascular bundle of a leaflet of cycas is ______.

  1. endarch or exarch

  2. endarch

  3. exarch

  4. mesarch

  5. none of the above.


Correct Option: D
Explanation:

Here, there is more than one strand of primary xylem in a stem or root, and the xylem develops from the middle of a strand in both directions. Such an arrangement of centripetal and centrifugal xylem is called diploxylic condition.

Vegetative reproduction occurs in cycas by __________.

  1. strobilus

  2. budding

  3. gemmae

  4. bulbils

  5. fragmentation


Correct Option: D
Explanation:

Bulbils are tiny secondary bulb that forms in the angle between a leaf and stem or in place of flowers on certain plants like cycas.

The leaf of cycas shows ______.

  1. hydrophytic character

  2. xerophytic character

  3. mesophytic characters

  4. halophytic characters

  5. lithophytic characters


Correct Option: B
Explanation:

Xerophytes reside in dry conditions. Cycas possess xerophytic characters as it grows in the scarcity of water.

Which kind of vernation does the young leaves of cycas have?

  1. Circinate vernation

  2. Convolute vernation

  3. Involute vernation

  4. Twisted vernation

  5. None of the above


Correct Option: A
Explanation:

When the leaf emerges, it is tightly curled so that the tender growing tip of the frond (and each subdivision of the frond) is protected within a coil.

The phloem of vascular system of cycas is ________.

  1. devoid of tracheids

  2. with tracheids

  3. devoid of companion cells

  4. devoid of sieve tubes

  5. devoid of parenchyma


Correct Option: C
Explanation:

Gymnosperms like cycas consists of phloem without companion cells.

The vascular bundle of cycas stem are ____________.

  1. conjoint

  2. radial

  3. collateral and closed

  4. conjoint, collateral and open

  5. conjoint, collateral and closed


Correct Option: D
Explanation:

Gymnosperm stem usually contains conjoint,  collateral and open vascular bundles, i.e.,  cambium is present between xylem and phloem and is responsible for the secondary growth.

The male cone of cycas is made up of groups of ____________.

  1. microsporophyll

  2. megasporophylls

  3. sporophylls

  4. archegonia

  5. antheridia


Correct Option: A
Explanation:

It is a leaflike structure that bears microsporangia. Male cone of cycas is made up of groups of microsporophyll.

Pollination in pinus is __________.

  1. entomophilous

  2. anemophilous

  3. hydrophillous

  4. zoophilous

  5. anthrophilous


Correct Option: D
Explanation:

Zoophily is a pollination in which pollens are distributed by animals.

Which of the following structures is absent from the xylem of cycas?

  1. Protoxylem

  2. Metaxylem

  3. Trachea

  4. Tracheids

  5. Fibres


Correct Option: C
Explanation:

In gymnosperms xylem only consists of tracheids, parenchyma and fibres.

What Cycas shows:

  1. Simple polyembryony

  2. Cleavage polyembryony

  3. Simple and cleavage polyemryony both

  4. No polyembryony

  5. Apospory


Correct Option: A
Explanation:

In simple polyemryony many eggs may be fertilized simultaneously resulting into the formation of many embryos.

What type of leaf does a Cycas plant have?

  1. Unipinnately compound

  2. Bipinnately compound

  3. Tripinnately compound

  4. Paripinnately compound

  5. Tetrapinnately compound


Correct Option: A
Explanation:

Yes, it is correct. Once-divided leaf blades having leaflets arranged on single side of a rachis are unipinnately compound leaves.

In cycas which structure is equivalent to stamens?

  1. Megasporophyll

  2. Microsporophyll

  3. Microsporangium

  4. Megasporangium

  5. Male cone


Correct Option: B
Explanation:

Microsporophyll are the male cones which possess microsporangia. These are equivalent to the stamens of angiosperms.

Which of the following structures are similar in Fern and cycas?

  1. Cambium

  2. Ciliated gametes

  3. Trachea

  4. Seeds

  5. Fruits


Correct Option: B
Explanation:

Both the groups contain gametes that possess cilia, and which makes them motile.

Which statement is true regarding Cycas?

  1. Monoecious and seed bearing.

  2. Dioecious and seed bearing.

  3. Seedless monoecious.

  4. Seedless dioecious.

  5. Fruit forming and dioecious.


Correct Option: B
Explanation:

These have male reproductive organs in one individual and female in another like gymnosperms.

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