NEET Biology : Sexual Reproduction in flowering Plants

Which one of the following pairs of plant structures has haploid number of chromosomes

• Nucellus and antipodal cells

• Egg nucleus and secondary nucleus

• Megaspore mother cell and antipodal cells

• Egg cell and antipodal cells

Apomixis is

• formation of seeds by fusion of gametes

• formation of seeds without syngamy and meiosis

• formation of seeds with syngamy but no meiosis

• none of the above

Assertion : Emasculation prevents self- pollination in flowers.

Reason : Emasculation is the removal of anthers from a bisexual flower.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Upon fertilization, what structure develops from carpel?

• Testa

• Tegmen

• Pericarp

• Perisperm

Assertion: Maize is an albuminous seed. 

Reason: Endosperm is completely absorbed by its growing embryo

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion : Protandry and protogyny ensures cross fertilization.

Reason : Cross fertilization introduces variation in progeny.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion: Nuclear endosperm is formed by subsequent nuclear division without wall formation.

Reason: Coconut is an example of such endosperm, where the endosperm remains nuclear throughout the development of the fruit

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Even after killing the generative cell with a laser beam, the pollen grain of a flowering plant germinates and produces normal pollen tube because

• laser beam stimulates pollen germination and pollen tube growth

• the laser beam does not damage the region from which pollen tube emerges

• the contents of killed generative cell permits germination and pollen tube growth

• the vegetative cell has not been damaged

Assertion: In some species of asteraceae and poaceae seeds are formed without fertilization.

Reason: Formation of fruit without fertilization is called parthenocarpy.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion : Pollen mother cells (PMCs) are the first male gametophytic cells.

Reason : Each PMC gives rise to two pollens.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false