Tag: biochemistry and the environment

Questions Related to biochemistry and the environment

Plastic used to preserve yogurts is replaced with a polymer called polylactic acid is an example of _______.

  1. green chemistry

  2. waste management

  3. green revolution

  4. none of above


Correct Option: A
Explanation:

Since usage of petroleum-based plastic is harmful to the environment, a polymer called polylactic acid, made using micro-organisms to convert cornstarch into a resin, is used to preserve yogurt. The resulting polymer is used to replace rigid petroleum-based plastic used in yogurt containers and water bottles and is environment-friendly. It is an application of green chemistry

Which one of the following is not an application of green chemistry?

  1. Replacement of CFCs by ${CO} _{2}$ as lowing agent in the manufacture of polystyrene foam sheets

  2. Reacting methylamine and phsogene to produce metyl isocyanate

  3. Replacement of organotions by sea-nine as anti fouling compound in sea marines

  4. Catalytic dehydrogenation of the diethanol amine withou using cyanide and formaldehyde


Correct Option: A

Shrinkage of concrete depends upon the: 

  1. relative humidity of the atmosphere & passage of time

  2. the moisture in the surrounding

  3. applied stress

  4. raining factor


Correct Option: A
Explanation:

 Drying shrinkage is defined as the contracting of a hardened concrete mixture due to the loss of capillary water. This shrinkage causes an increase in tensile stress, which may lead to cracking, internal warping, and external deflection before the concrete is subjected to any kind of loading.

Shrinkage depends upon the relative humidity of the atmosphere & passage of time.
Hence, the correct option is A.

Green chemistry is:

  1. way of thinking and utilising the existing knowledge and principles of chemistry and other sciences

  2. study of plants for making the environment clean

  3. both A and B

  4. None of the above


Correct Option: A
Explanation:

Green chemistry, also called sustainable chemistry, is an area of chemistry and chemical engineering focused on the designing of products and processes that minimize the use and generation of hazardous substances.

Green chemistry applies across the life cycle of a chemical product, including its design, manufacture, use, and ultimate disposal

$Statement\ I-$ Algal blooms, caused by phosphates, are beneficial to aquatic ecosystems.
BECAUSE
$Statement\ II-$ Algal blooms are associated with rapidly increasing rates of photosynthesis which lead to dissolve oxygen content in the water leading to much higher than normal levels.

  1. Statement $I$ is true, Statement $II$ is true

  2. Statement $I$ is true, Statement $II$ is false

  3. Statement $I$ is false, Statement $II$ is true

  4. Statement $I$ is false, Statement $II$ is false

  5. Statement $I$ is true, Statement $II$ is true and is correct explanation of the phenomena described in $I$


Correct Option: E

_________ are called the elements of the weather.

  1. The temperature

  2. Humidity

  3. Wind speed

  4. All of the above


Correct Option: D
Explanation:

The elements of weather are:

1. Temperature
2. Humidity
3. Wind speed

The monsoon winds that carry a lot of water to India come from the:

  1. North east

  2. North west

  3. South east

  4. South west


Correct Option: D
Explanation:

The winds coming from the southwest blow over the Indian ocean and bring lots of rains.

What does Green Chemistry in terms of environment mean?

  1. Greenhouse effect

  2. Reaction related to depletion of ozone layer

  3. Photosynthetic reactions in plants

  4. Reduction in the use and production of hazardous chemicals


Correct Option: D
Explanation:

Green chemistry is also known as environmentally sustainable chemistry. 


Perhaps, the most widely accepted definition of green chemistry is the one offered by chemists Paul Anastas and John Warner, who defined green chemistry as the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances.

Hence, option D is correct.

The average weather pattern taken over a long time, say _______, is called the climate of the place.

  1. $10\ years$

  2. $20\ years$

  3. $25\ years$

  4. $30\ years$


Correct Option: C
Explanation:

The average weather pattern taken over a long time of about $25 years$ is known as climate of that place.

All changes in the weather are caused by the:

  1. Earth

  2. Sun

  3. Moon

  4. none of the above


Correct Option: B
Explanation:

The energy that the Earth receives from the Sun is the basic cause of our changing weather. Solar heat warms the huge air masses that comprise large and small weather systems.However, at higher altitudes, the atmosphere reacts strongly to changes in solar activity.