STD 12 - 12. ecosystem — NEET STD 11 Science — Question

Trachea, tracheids, wood fibres and parenchyma tissues are found in

Blackman’s law of limiting factor is applied to

Read the following and choose the option with all incorrect statements.
(i) In the hypogynous flower the gynoecium occupies the highest position while the other parts are situated below it
(ii) In epigynous flowers, the margin of thalamus grows upwards enclosing the ovary partially and getting fused with it, the other parts of flower arise above the ovary.
(iii) In hypogynous flower ovary is said to be superior.
(iv) In plum, rose and peach; flower is epigynous and ovary is said to be inferior
(v) The mode of arrangement of sepals or petals in floral bud with respect to the other members of the same whorl is known as aestivation.
(vi) When sepals or petals in a whorl just touch one another at the margin, without overlapping as in Calotropis, it is said to be valvate.
(vii) If the margins of sepals or petals overlap one another but not in any particular direction as in Cassia and gulmohur, the aestivation is called imbricate.
(viii) A fertile stamen is called staminode.
(ix) When stamens are attached to the petals, they are epipetalous as in lilly, or epiphyllous when attached to the perianth as in the flowers of brinjal.
(x) The stamens may be united into one bunch or one bundle called monoadelphous as in china rose.
(xi) A carpel consists of three parts namely stigma, style and ovary.
(xii) The stigma is usually at the tip of the Style and is the receptive surface for pollen grains.
(xiii) Each ovary bears one or more ovules attached to a flattened, cushion-like placenta.
(xiv) When more than one carpel is present, they may be free and are called syncarpous.
(xv) After fertilization, the ovules develop into seeds and the ovary matures into a fruit.

Cell wall of Spirogyra is composed of

It degenerate after fertilization in angiosporm