Question of Exercise-2

Chromosomal Basis of Inheritance of Class 12

Question
Maximum number of chromosomes have been recorded in

Answer

Option 1 Lycopodium

Option 2 Cycas

Option 3 Ophioglossum  

Option 4 Triticum

Frequently Asked Questions

Chilka lake is situated in..............and famous for.............

A: Tamilnadu, flamingos

B: Kerala, elephants

C: Orissa, flamingos

D: Karnataka, Flamingos

 

Solution:

Correct Option is: (C)

Orissa, flamingos

 

Explanation :- 

Chilka lake is the largest brackish estuary lake in India. 

It covers portions of three districts of state Orissa, namely Puri, Khurda and Ganjam.

It flows into the bay of bengal and covers an area approximately 1100 km2. 

The lake is famous for housing migratory birds, Flamingos.

Chilka lake is not present in Tamilnadu, Kerala, and Karnataka.

 

What is heterospory Briefly comment on its significance Give two examples

Solution:

Explanation :- 

Heterospory is an event in which two different types of spores i.e microspore and megaspore are produced by the plant. 

The microspore develops into male gametophyte whereas megaspores develop into female gametophyte.

Male gametophyte releases male gamete which fuses with female gamete formed by female gametophyte. 

After fusion of gametes, zygote is formed. 

Zygote develops inside the female gametophyte.

The preservation and development of megaspore inside the female gametophyte, guarantees right development of zygote.

Later on, zygote develops into sporophyte. 

The development of seed practice is associated with the preservation of the megaspores inside the megasporangium or female gametophyte.

Therefore, heterospory is very important from an evolutionary point of view as it is the ancestor of the seed pattern. 

 

Examples :- Pinus , Cycas etc.

 

Pollen grains are produced in

A: Sepals

B: Petals

C: Anthers

D: Carpel

 

Solution:

Explanation: 

The male organ in the flowering plant is depicted by the stamen. It consists of the anther, stalk and filament. Anther consists of the pollen sacs which are involved in the production of pollen grains.

 

Correct Option is: (C)

Anthers

 

Which of the following are the male reproductive organs of a flower

A: Sepals

B: Petals

C: Stamens

D: Carpels

 

Solution:

Explanation:

The options are the parts of the flower.

Sepals and petals are the accessory parts of a flower

The reproductive part or the organs are stamens and carpels.

The male reproductive organ is stamens which have anther and filament.

While the female reproductive part is carpels, the pistil which have different parts like stigma, style, ovary and ovule.

 

Correct Option is: (C)

Stamens

 

List the parts of a typical dicot embryo

Solution:

Explanation:

  • Parts of typical dicot embryos includes- Plumule, cotyledons, hypocotyl, radical and root cap.
  • A typical dicotyledonous embryo, consists of an embryonal axis and two cotyledons.
  • The portion of the embryonic axis above the level of cotyledons is the epicotyl, which terminates with the plumule or stem tip.
  • The cylindrical portion below the level of cotyledons is hypocotyl that terminates at its lower end in the radical or root tip.
  • The root tip is covered with a root cap

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