Tag: asexual and sexual reproduction in plants

• After fertilisation has occurred in the ovule, the ovule gets transformed into seed.

• Aril is a fleshy seed appendage which arise from the funiculus. It surrounds the ovule in the post fertilisation stages.

• After fertilization, the nucellus persists in the seed in the form of perisperm.

• Polar nuclei on fusion with the male gamete form a triploid primary endosperm mother cell which develops into endosperm.

Hence, the correct match is a- 3, b- 2, c- 4, d- 1

So, the correct answer is B.

• Amphitropous ovule- The body of ovule gets curved along with the embryo sac in such a way that it becomes horseshoe-shaped. This type of ovule is found in families like Butamaceae, Loganiaceae.

• Campylotropous ovule- This type of ovule is similar to Anatropous ovule but curvature is less than that of anatropous ovule. Campylotropous ovule is found in families like Chenopodiaceae. 

• Circinotropous ovule- In this type of ovule, the length of funiculus becomes increased and it covers the whole ovule. It is found in families like Cactaceae (Opuntia).

• Orthotropous ovule is the simplest and primitive type of ovule. In this type of ovule, micropyle, chalaza and funiculus lie in one vertical plane. Examples , all gymnosperms, Polygonum.

Hence, Opuntia has circinotropous ovule. So, the correct answer is C.

The cuticle is a waxy substance which fills the space between the Nucellus and inner integument and between the outer and inner integuments of the ovule. Both the integuments are covered with a layer of cuticle.

Hence, the cuticle is present over the outer part of integument.

So, the correct answer is A.

The process of formation of microspores from spore mother cells (SMC) or Microspore mother cell is called microsporogenesis. Very important changes occur in the Tapetum and locule of the anther during microsporogenesis. In the beginning, when the locule is preparing for microsporogenesis, there are plasmodesmatal connections between Tapetal and Tapetal cells, tapetal and SMC and between SMC and SMC. Very small molecules can pass through these connections. Towards the end of zygotene-pachytene stage of prophase I of meiosis, callose layer starts to get depositing around each SMC and the plasmodesmatal connections are cut off. This callose is contributed by the dictyosomes present in the peripheral cytoplasm of the microspore mother cell.

Hence, Microspore mother cells produces callose for breaking the plasmodesmatal connections among microspore mother cells.

So, the correct answer is A.

•Funicle is the stalk of ovule by which it adheres to the placenta.

•Integuments are the protective coverings of the ovule.

•Chalaza is the basal part of the ovule which is opposite to the micropyle.

•Hilum is a structure that attaches the body of the ovule to the funiculus i.e. stalk of the ovule.

•Micropyle is a small opening in the ovule through which pollen tube enters the ovule during fertilisation.

Hence, the correct match is:

1-b, 2-c, 3-e, 4-d, 5-a

So, the correct answer is A.

• Anatropous ovule - The most common type of ovules which occurs in more than 80% of angiosperm families. The body of ovule is rotated by 180° and micropyle comes near to the funiculus. Chalaza and micropyle lie in the straight line but hilum is at 90° to the micropyle.

• Amphitropous ovule - The body of ovule gets curved along with the embryo sac in such a way that it becomes horseshoe-shaped. This type of ovule is found in families like Butamaceae, Loganiaceae.

• Campylotropous ovule - This type of ovule is similar to Anatropous ovule but the curvature is less than that of an anatropous ovule. The campylotropous ovule is found in family Chenopodiaceae and in Pisum and Capsella.

So, the correct answer is D.

Megaspore mother cell undergoes meiosis to form four haploid megaspores. These megaspores are arranged in the form of a linear tetrad. The megaspore mother cell undergoes first meiotic division and a transverse wall is laid down resulting in the formation of a dyad. The two cells of the dyad similar divides transversely resulting in the formation of a linear tetrad. Tetrahedral, decussate, and isobilateral tetrads are found in case of microspores i.e. such tetrads are formed during microsporogenesis. Hence, tetrad of megaspores is generally linear.

So, the correct answer is B.

•Campylotropous ovule- This type of ovule is similar to Anatropous ovule but curvature is less than that of anatropous ovule. Micropyle is near to the funiculus. Chalaza and micropyle lie in the straight line but hilum is at 90° to micropyle. Campylotropous ovule is found in family Chenopodiaceae and in Pisum and Capsella.

•Amphitropous ovule- The body of ovule gets curved along with the embryo sac in such a way that it becomes horseshoe-shaped. This type of ovule is found in families like Butamaceae, Loganiaceae.

•Circinotropous ovule- In this type of ovule, the length of funiculus becomes increased and it covers the whole ovule. It is found in families like Cactaceae (Opuntia).

•Hemianatropous ovule- The body of ovule is turned through 90° and micropyle and chalaza lie in a straight line but funiculus is at right angle or 90° with both these two. E.g. Ranunculaceae.

Since Opuntia has Circinotropous ovule.

So, the correct answer is C.

Rest of the options are incorrect as Testa is the outer most covering of seed, micropyle is a small opening in seed coatthrough which water enters seed and chalaza is a tissue where nucellus and integument are joined. Nutrients from the plant travel through vascular tissue in the funiculus and outer integuments through the chalaza into the nucellus. 

Pollen grain- A pollen grain is a microscopic body that contains the male reproductive cell of a plant. Pollen grains represent the male portion of the reproductive process in plants and trees.

Seed- A seed is an embryonic plant enclosed in a protective outer covering. The embryo is developed from the zygote and the seed coat from the integuments of the ovule.

Embryo sac- the female gametophyte of a seed plant consisting of a thin-walled sac within the nucellus that contains the egg nucleus and other nuclei which give rise to endosperm on fertilization.

So the correct option is 'all of these'