Tag: sexual reproduction in plants

Questions Related to sexual reproduction in plants

Caruncle develops from

  1. Outer integument

  2. Cotyledon

  3. Funiculus

  4. Inner integument


Correct Option: A
Explanation:

A. Seed in many members of the Euphorbiaceae, such as castor, the soft outgrowth capping the hard seed is formed by proliferation of the cells at the tip of the outer integument called caruncle. It is rich in starch and sugars.

B. Cotyledons-  They  are thin, semi-transparent and oval in outline in castor. They have palmate venation. The middle costa or rib is more prominent and bears a few lateral veins.

C. Funiculus- It is a stalk like structure which attaches the ovule to the placenta.

D. Inner integument- It forms the tegman, inner covering of seed.

So, the correct answer is ‘Outer Integument’.

Seed develops from

  1. Embryo

  2. Ovule

  3. Embryo sac

  4. Ovary


Correct Option: B
Explanation:
After fertilization,
A. The zygote develops into an embryo.
B. The ovule develop into a seed.
C. The triploid primary endosperm nucleus forms an endosperm.
D. The ovary transformed into a fruit.
So, the correct answer is 'Ovule'.

Which of the following structure forms fruit?

  1. Leaf

  2. Flower

  3. Root

  4. Ovary


Correct Option: D
Explanation:
Fruits are the mature ovary or ovaries of one or more flowers. Fruits are produced only by flowering plants (angiosperms). Following pollination of the flower, the fertilized ovules develop into seeds while the surrounding ovary wall forms the fruit tissue or pericarp.
So, the answer is D.

The structure which can show the effect of traits brought by the male gamete immediately after its formation is

  1. Embryo

  2. Cotyledons

  3. Endosperm

  4. Plumule


Correct Option: C
Explanation:
Endosperm nourishes the developing embryo. It is formed by the fusion of male gamete with the diploid secondary nucleus that results in the formation of a triploid primary endosperm mother cell. In double fertilization, one male gamete fuses with the egg cell to form the zygote and the other male gamete fuses with the diploid secondary nucleus to form the endosperm. It is formed immediately after fertilization because it has to nourish the developing embryo. So, the correct answer is C.

Cardamoms or Cardamons are ripe and dried fruits of

  1. Elettaria cardamomum

  2. Cinnamomum zeylenicum

  3. Eugenia caryophyllata

  4. Zingiber officinale


Correct Option: A
Explanation:

Cardamoms are ripe and dried fruits of  Elettaria cardamomum, commonly called green or true cardamoms. They are called the 'queen of spices' because of the aroma and taste. 

In angiosperms, triple fusion produces

  1. Polar nucleus

  2. Secondary nucleus

  3. Primary endospermic nucleus

  4. Zygotic nucleus


Correct Option: C
Explanation:

Double fertilization process is observed in angiosperms in which syngamy takes place in the beginning. After syngamy the pollen tubes releases two male gametes, one fuses with the nucleus of egg cell and the other with the central cell and forms primary endosperm nucleus (PEN). The process is called as triple fusion as endosperm is triploid in nature.

So, the correct option is 'Primary endospermic nucleus'.

Endosperm of flowering plants develops from

  1. Haploid nucleus

  2. Diploid nucleus

  3. Triploid nucleus

  4. Tetraploid nucleus

  5. Polyploid nucleus


Correct Option: C
Explanation:
Flowering plants are Angiosperms. Angiosperms have a unique phenomenon of "Double Fertilisation" in which, after the release of two male gametes inside the embryo sac by the pollen tube, one male gamete i.e. the first male gamete which is too near to egg fuses with egg nucleus and this phenomenon is known as fertilisation or syngamy. During syngamy, a zygote is formed. The other male gamete i.e. the second male gamete migrates towards the secondary nucleus (formed from the fusion of two polar nuclei) and fuses with it. This phenomenon is known as triple fusion and results in the formation of a triploid primary endosperm mother cell which forms triploid endosperm. Thus, Endosperm is formed from a triploid nucleus.
So, the correct answer is C.

Nucellus in fertilized ovuled is known as ______________.

  1. Perisperm

  2. Endothecium

  3. Perithecium

  4. Epistase


Correct Option: A

Seeds contain embryo.

  1. True

  2. False


Correct Option: A
Explanation:
A seed is an embryonic plant enclosed in a protective outer covering known as the seed coat.
It is the product of the ripened ovule which occurs after fertilization and some growth within the mother plant. The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.
Therefore, the correct answer is option A.

A fruit is a

  1. Ripened ovary

  2. Ripened ovule

  3. Seed plus its integuments

  4. Fused carpel


Correct Option: A
Explanation:

Fruit is a seed-bearing structure in flowering plants formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate seeds.  A fruit results from maturation of one or more flowers, and the gynoecium of the flower forms all or part of the fruit. The outer, often edible layer, is the pericarp, formed from the ovary and surrounding the seeds, although in some species other tissues contribute to or from the edible portion. The pericarp may be described in three layers from outer to inner, the epicarp, mesocarp and endocarp. 

So the correct option is 'ripened ovary'.