STD 11 - 8. Cell the unit of life — NEET STD 11 Science — Question

Which of the following statements are true for stamen and microsporangium ?
(i) A typical angiosperm anther is bilobed, dithecous.
(ii) The microsporangia develop further and become pollen sacs.
(iii) Microsporangium generally surrounded by four wall layers.
(iv) The epidermis, endothecium and middle layers of anther perform the function of protection.
(v) The innermost wall layer of anther is the tapetum and it nourishes the developing pollen grains.
(vi) Cells of the tapetum generally have one nucleus.

Haplontic life cycle is followed by

Intercalary meristem results is

Choose correct option w.r.t. spongy mesophyll in dicot leaf.

Organell labelled by which alphabets is absent in animal cells?

Which of the following structures show unlimited growth in plants?

In following, which is not common for chloroplasts and mitochondria?

Tip of ecological pyramid is occupied by

Which of the following statements is true regarding chemiosmotic hypothesis ?
(i) Protons or hydrogen ions that are produced by the splitting of water accumulate within the lumen of the thylakoids.
(ii) Primary accepter of electron which is located towards the outer side of the thylakoids membrane transfers its electron not to an electron carrier but to an H carrier.
(iii) The NADP reductase enzyme is located on the stroma side of the membrane.
(iv) Protons are also removed from the stroma by NADP.
(v) Due to removal of proton by NADP, within the chloroplast, protons in the stroma decrease in number, while in the lumen there is accumulation of protons. This creates a proton gradient across the thylakoid membrane.
(vi) Due to accumulation of protons in lumen of thylakoid measurable increase in pH in the lumen.