Question
Most leaves have the upper surface more green and shiny than the lower one. Why?
✓
Answer
The chloroplasts are concentrated in the upper layers of the leaf which helps cells to trap the sunlight quickly. Also the epidermis is covered by a waxy, waterproof layer of cuticle. This layer is thicker on the upper surface than the lower one. Hence most leaves have the upper surface more green and shiny than the lower one.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Given below is an apparatus used to study a particular process in plants. Study the same and answer the questions that follow :
(i) Name the apparatus.
(ii) Mention one limitation of this apparatus.
(iii) Which phenomenon is studied with the help of this apparatus?
(iv) What is the function of the part marked ‘reservoir’?
(v) What is the role of the air bubble in the experiment?
(i) Name the apparatus.
(ii) Mention one limitation of this apparatus.
(iii) Which phenomenon is studied with the help of this apparatus?
(iv) What is the function of the part marked ‘reservoir’?
(v) What is the role of the air bubble in the experiment?
Make a punnett square for finding out the proportion of different genotypes in the progeny of a genetic cross between.
A pure tall (TT) pea plant with a pure dwarf (tt) pea plant.
A pure tall (TT) pea plant with a pure dwarf (tt) pea plant.
Differentiate between primary and accessory reproductive organs
Match the items in column I with the closely related ones in column II.
→| Column I | Column II |
| (i) Chlorofluocarbons (CFCs) (ii) Flyash (iii) Cow dung (iv) $CO_2$ and methane (v) Sulphur dioxide (vi) Iodine - 131 |
(a) Global warming (b) Biodegradable (c) Nuclear radiation pollutant (d) acid rain (e) Industrial waste (f) Ozone depletion |
Mention characteristic features of mitosis.
Explain in brief the opening and closing mechanism of stomata.
match the conditions in column A with the cause in column B.
| A (Condition) | B (Cause) | ||
| a | Dwarfism and mental retardation | 1 | shortage of glucose in blood |
| b | Diabetes mellitus | 2 | Over secretion of growth hormone |
| c | Excess of glucose in blood | 3 | Insulin shock |
| d | Gigantism | 4 | Over secretion of thyroxine |
| e | Enlargement of breasts in adult males | 5 | Hypothyroidism |
| f | Exophthalmic goitre | 6 | Over secretion of cortical hormones |
Explain the Term: Glomerulus
What is meant by positive and negative tropic movements in plants? Explain them by giving suitable examples.
Enumerate the structural differences between white blood cells and red blood cells.