Height of a plant is regulated by:a) DNA which is directly influenced by growth hormone.b) Genes which regulate the proteins directly.c) Growth hormones under the influence of the enzymes coded by a gene.d) Growth hormones directly under the influence a gene.

Height of a plant is regulated by:a) DNA which is directly influenced by growth hormone.b) Genes which regulate the proteins directly.c) Growth hormones under the influence of the enzymes coded by a gene.d) Growth hormones directly under the influence a gene.112 A sportsman, after a long break of his routine exercise, suffered muscular cramps during aheavy exercise session. This happened due to:a) lack of carbon dioxide and formation of pyruvate.b) presence of oxygen and formation of ethanol.c) lack of oxygen and formation of lactic acid.d) lack of oxygen and formation of carbon dioxide.113 An object is placed in front of a convex mirror. Its image is formed :a) at a distance equal to the object distance in front of the mirror.b) at twice the distance of the object in front of the mirror.c) half the distance of the object in front of the mirror.d) behind the mirror and it’s position varies according to the object distance.114 When light enters the atmosphere it strikes on extremely fine particles, which deflect therays of light in all possible directions, This is due to -a) reflection of lightb) atmospheric refractionc) scattering of lightd) dispersion of light115 In 1987, an agreement was formulated by the United Nations Environment Programme(UNEP) to freeze the production of “X” to prevent depletion of “Y”. “X” and “Y”respectively referred here are:a) Ozone; CFCsb) CFCs; rays UVc) CFCs; Ozoned) UV rays; Diatomic oxygen116 Which of the following features relates to biodegradable substances?a) Broken down by biological processesb) Remain inertc) Persist in environment for long timed) May harm the ecosystem1Question No. 17 to 20 consist of two statements – Assertion (A) and Reason (R). Answerthese questions selecting the appropriate option given below:a) Both A and R are true, and R is the correct explanation of A.b) Both A and R are true, and R is not the correct explanation of A.c) A is true but R is false.d) A is false but R is true.17 Assertion: Rusting of Iron is endothermic in nature.Reason: As the reaction is slow, the release of heat is barely evident.118 Assertion: Probability of survival of an organism produced through sexual reproduction ismore than that of organism produced through asexual mode.Reason: Variations provide advantages to individuals for survival.1419 Assertion : A compass needle is placed near a current carrying wire. The deflection of thecompass needle decreases when the magnitude of the current in the wire is increased.Reason : The strength of a magnetic field at a point near the conductor increases onincreasing the current.120 Assertion: Biodegradable substances result in the formation of compost and naturalreplenishment.Reason: It is due to breakdown of complex inorganic substances into simple organicsubstances.1Section-BQuestion No. 21 to 26 are very short answer questions21 Dil. HCl is added to Zn granules.” How will you prove that chemical change has taken placehere? Support your response with two arguments.222 State the post-fertilisation changes that lead to fruit formation in plants. 223 What is the purpose of making urine in the human body? Name the organs that stores andreleases the urine.ORWhy do arteries have thick and elastic walls whereas veins have valves?224 The refractive indices of three media are given below:Medium Refractive IndexA 1.6B 1.8C 1.5A ray of light is travelling from A to B and another ray is travelling from B to C.(a) In which of the two cases the refracted ray bends towards the normal?(b) In which case does the speed of light increase in the second medium?Give reasons for your answe

Does height in plants have a genetic cause, an environmental cause or both?

Adaptive mechanisms are also utilized by plants to increase or decrease growth in organs that directly or indirectly participates in nutrient acquisition.Select one:a.TRUEb.FALSE

Which of the following are functions that hormones regulate?Multiple select question.GrowthSkeletal muscle contractionMetabolismReproduction

Identify two challenges that plants had to overcome in order to grow taller.