Multiple Choice Questions

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Biological Oxygen Demand (BOD) is a measure of

  • Industrial wastes poured into water bodies

  • The extent to which water is polluted with an organic compound

  • Amount of carbon monoxide inseparably combined with haemoglobin

  • Amount of oxygen needed by green plants during the night 


B.

The extent to which water is polluted with an organic compound

Biological Oxygen Demand (BOD) is a meaure of polluting organic matter present in a sample of water. BOD is higher in polluted sewage water and is connected with both microbes and organic matters. When larger amount of sewage is dumped in to water, the BOD will increase.


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A polygenic inheritance in human beings is

  • Skin colour

  • Sickle cell anaemia

  • Colour blindness

  • Phenylketonuria


Double fertilization occurs in

  • Riccia

  • Pteridium

  • Cycas

  • Capsella


Ten percent law of energy transfer in a food chain is given by

  • Schimper

  • Elton

  • Haeckel

  • Lindemann


The Montreal Protocol refers to

  • Persistent organic pollutants

  • Global warming and climate change

  • Substances that deplete the ozone layer

  • Biosafety of genetically modified organisms


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One gene-one enzyme relationship was established for the first time in

  • Neurospora crassa

  • Salmonella typhimurium

  • Escherichia coli

  • Diplococcus pneumoniae


Powdery mildew of wheat is caused by a species of

  • Puccinia

  • Erysphe

  • Ustilago

  • Albugo


In gymnosperms, the pollen chamber represents

  • A cell in the pollen grain in which the sperms are formed

  • A cavity in the ovule in which pollen grains are stored after pollination

  • An opening in the megagametophyte through which the pollen tube approaches the egg

  • The microsporangium in which pollen grains develop


Nucleic acid segment tagged with a radiactive molecule is called

  • Clone

  • Probe

  • Plasmid

  • Vector


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The Okazaki fragments in DNA chain growth

  • Results in transcription

  • Polymerise in the 3' to 5' direction and forms replication fork

  • Prove semi-conservative nature of DNA replication

  • Polymerise in the 5' to 3' direction and explain 3' to 5 DNA replication