(l) No, the structure of the eye in each of the organisms is different. (ii) Fossils of certain dinosaurs/reptiles show imprints of feathers along with their bones but they could not fly presumably using the feathers for insulation. . Later, they developed/evolved and adapted feathers for flight, tRead more
(l) No, the structure of the eye in each of the organisms is different.
(ii) Fossils of certain dinosaurs/reptiles show imprints of feathers along with their bones but they could not fly presumably using the feathers for insulation.
. Later, they developed/evolved and adapted feathers for flight, thus becoming the
ancestors of present-day birds. (OR any other suitable evidence/example)
(a) (i) Hyphae/mycelium (ii) Sporangia (b) Structures protected by thick walls. Function: They germinate into new individuals under favourable conditions.
(a) (i) Hyphae/mycelium (ii) Sporangia
(b) Structures protected by thick walls.
Function: They germinate into new individuals under favourable conditions.
Four methods of contraception: (l) Mechanical or barrier method OR Male or female condoms. (ii) Use of hormonal preparations OR Oral pills/i-pill/Saheli. (iii) Use of loop or copper-T OR IUCD. (iv) Surgical method OR tubectomy/vasectomy. Effect on health and prosperity: (i) Health of n omen is maintRead more
Four methods of contraception:
(l) Mechanical or barrier method OR Male or female condoms.
(ii) Use of hormonal preparations OR Oral pills/i-pill/Saheli.
(iii) Use of loop or copper-T OR IUCD.
(iv) Surgical method OR tubectomy/vasectomy.
Effect on health and prosperity:
(i) Health of n omen is maintained.
(ii) Parents can give more attention to their children.
(iii) More resources can be made available for the improvement in living standard.
. No. of periods: 7 . Valency across a period increases from 1 to 4, then decreases from 4 to zero. . Metallic character of elements across a period decreases. . Valency down a group remains the same. . Atomic size of elements down a group increases.
. No. of periods: 7
. Valency across a period increases from 1 to 4, then decreases from 4 to zero.
. Metallic character of elements across a period decreases.
. Valency down a group remains the same.
. Atomic size of elements down a group increases.
Four activities: (i) Reduce excessive use of natural resources like water, fossil fuels, etc. (ii) Reuse of some resources instead of wasting (throwing) them, like empty bottles. (iii) Recycle the materials like paper to reduce the pressure on existing natural resources. (iv) Changes in lifestyle, pRead more
Four activities:
(i) Reduce excessive use of natural resources like water, fossil fuels, etc.
(ii) Reuse of some resources instead of wasting (throwing) them, like empty bottles.
(iii) Recycle the materials like paper to reduce the pressure on existing natural resources.
(iv) Changes in lifestyle, personal attitudes and practice
(l) Planaria, insects, octopus and vertebrates all have eyes. Can we group eyes of these animals together to establish a common evolutionary origin? Justify your answer. (ii) “Birds have evolved from reptiles”. State evidence to prove the statement.
(l) No, the structure of the eye in each of the organisms is different. (ii) Fossils of certain dinosaurs/reptiles show imprints of feathers along with their bones but they could not fly presumably using the feathers for insulation. . Later, they developed/evolved and adapted feathers for flight, tRead more
(l) No, the structure of the eye in each of the organisms is different.
See less(ii) Fossils of certain dinosaurs/reptiles show imprints of feathers along with their bones but they could not fly presumably using the feathers for insulation.
. Later, they developed/evolved and adapted feathers for flight, thus becoming the
ancestors of present-day birds. (OR any other suitable evidence/example)
(a) Name the following: (l) Thread like non-reproductive structures present in Rhizopus. (ii) ‘Blobs’ that develop at the tips of the non-reproductive threads in Rhizopus. (b) Explain how these structures protect themselves and what is the function of the structures released from the ‘blobs’ in Rhizopus
(a) (i) Hyphae/mycelium (ii) Sporangia (b) Structures protected by thick walls. Function: They germinate into new individuals under favourable conditions.
(a) (i) Hyphae/mycelium (ii) Sporangia
See less(b) Structures protected by thick walls.
Function: They germinate into new individuals under favourable conditions.
List any four methods of contraceptions used by humans. How does their use have a direct effect on the health and prosperity of a family
Four methods of contraception: (l) Mechanical or barrier method OR Male or female condoms. (ii) Use of hormonal preparations OR Oral pills/i-pill/Saheli. (iii) Use of loop or copper-T OR IUCD. (iv) Surgical method OR tubectomy/vasectomy. Effect on health and prosperity: (i) Health of n omen is maintRead more
Four methods of contraception:
(l) Mechanical or barrier method OR Male or female condoms.
(ii) Use of hormonal preparations OR Oral pills/i-pill/Saheli.
(iii) Use of loop or copper-T OR IUCD.
(iv) Surgical method OR tubectomy/vasectomy.
Effect on health and prosperity:
See less(i) Health of n omen is maintained.
(ii) Parents can give more attention to their children.
(iii) More resources can be made available for the improvement in living standard.
Write the number of periods the Modern Periodic Table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group
. No. of periods: 7 . Valency across a period increases from 1 to 4, then decreases from 4 to zero. . Metallic character of elements across a period decreases. . Valency down a group remains the same. . Atomic size of elements down a group increases.
. No. of periods: 7
See less. Valency across a period increases from 1 to 4, then decreases from 4 to zero.
. Metallic character of elements across a period decreases.
. Valency down a group remains the same.
. Atomic size of elements down a group increases.
Everyone of us can do something to reduce our personal consumption of various natural resources. List four such activities based on 3-R approach.
Four activities: (i) Reduce excessive use of natural resources like water, fossil fuels, etc. (ii) Reuse of some resources instead of wasting (throwing) them, like empty bottles. (iii) Recycle the materials like paper to reduce the pressure on existing natural resources. (iv) Changes in lifestyle, pRead more
Four activities:
See less(i) Reduce excessive use of natural resources like water, fossil fuels, etc.
(ii) Reuse of some resources instead of wasting (throwing) them, like empty bottles.
(iii) Recycle the materials like paper to reduce the pressure on existing natural resources.
(iv) Changes in lifestyle, personal attitudes and practice