Tag: botany

Questions Related to botany

Which of the following statements is not correct regarding the genetic modification of crops?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. It makes crops more tolerant to abiotic stresses.

  2. It results in decreased efficiency of mineral usage by plants.

  3. It helps to reduce post harvest losses.

  4. In enhances the nutritional value of food.

Show answer
Correct Option: B
Explanation:
Genetic modification has:
(i) Made crops more tolerant to abiotic stress (cold, drought, salt, heat.)
(ii) Reduced reliance on chemical pesticides (pest-resistant crops).
(iii) Helped to reduce on post-harvest losses.
(iv) Increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil ).
(v) Enhanced nutritional value of food, e.g., Vitamin 'A' enriched rice.
In addition to these uses, GM has been used to create tailor-made plants to supply alternative resources to industries, in the form of starch, fuel, and pharmaceuticals. 
So, the correct answer is 'It results in decreased efficiency of mineral usage by plants.'

'Flavr Savr' variety of tomato which remains fresh for a longer period than normal tomato variety

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. Has high amount enzyme polygalacturonase

  2. Has reduced amount of enzyme polygalacturonase

  3. Is a pest resistant variety

  4. Is rich in vitamin A and prevents night blindness.

Show answer
Correct Option: B
Explanation:

The tomato variety 'Flavr Savr' presents an example where expression of a native tomato gene has been blocked. Fruit softening is promoted by the enzyme polygalacturonase, which degrades pectin. Production of polygalacturonase is blocked in the transgenic tomato variety 'Flavr Savr'. So, fruits of this tomato variety remain fresh and retain their flavour much longer than do the fruits of normal tomato varieties. Additionally, the fruits have a superior taste and increased total soluble solids.

So, the correct answer is 'Has reduced amount of enzyme polygalacturonase'.

Study the following statements and select the incorrect ones.


(i) 'Bt' in 'Bt cotton' indicates that is a genetically modified crop produced through biotechnology.
(ii) The anticoagulant 'hirudin' is being produced from transgenic Brassica napus seeds.
(iii) 'Flavr Savr' transgenic tomatoes remain fresh for a longer period than the normal tomato variety.
(iv) Golden rice is a transgenic variety of Oryza sativa, which is rich in $\beta$-carotene and helps to prevent night blindness.

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. (i) only

  2. (i) and (iv)

  3. (ii) and (iii)

  4. (i), (ii), (iii) and (iv)

Show answer
Correct Option: A

Which statements about genetically modified (GM) food is false?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. Scientists have used genetic modification, In various forms, as a mean of improving crop yields, crop quality, and pest resistance for many years.

  2. Genetic modification includes products made by artificial mutagenesis and by non-natural crosses between unrelated species.

  3. A major difficulty in labelling foods as 'GM-free' is that it is virtually impossible to measure genetically modified DNA or protein molecules in most food made from GM crops.

  4. The recent decision by McCain Foods to stop processing GM potatoes means that they will eventually use less pesticides to produce the potatoes that are required to make fries.

Show answer
Correct Option: D
Explanation:

GM food or genetically modified food is obtained from crops improved by artificial mutagenesis and non-natural crosses between unrelated species. GM food production does not involve use of pesticides etc., but includes incorporation of pest resistance genes either through mutation or through transferring it from an insect resistant species.

What is meant by GM foods?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. Growth modified foods

  2. Genetically modified food

  3. Growth marked foods

  4. Good mobility food

Show answer
Correct Option: B

A genetically modified crop can be formed by inserting the genes of

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. Another plant

  2. Bacteria

  3. Some animals

  4. All of the above

Show answer
Correct Option: D
Explanation:

Genetically modified crops (GMCs, GM crops or biotech crops) are plants used in agriculture, the DNA of which has been modified using genetic engineering techniques. In most cases the aim is to introduce a new trait to the plant, which does not occur naturally in the species. 

Examples in food crops include resistance to certain pests, diseases or environmental conditions, reduction of spoilage or resistance to chemical treatments (e.g., resistance to a herbicide) or improving the nutrient profile of the crop. 
Examples in non-food crops include production of pharmaceutical agents, biofuels and other industrially useful goods, as well as for bioremediation. A genetically modified crops can be formed by inserting the genes of other plants, bacteria, animals, etc.

Which country has decided to label those GM foods that are found to be safe?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. Brazil

  2. China

  3. Japan

  4. South Africa

Show answer
Correct Option: C
Explanation:

Genetically modified foods or GM foods, also genetically engineered foods, are foods produced from organisms that have had changes introduced into their DNA using the methods of genetic engineering.

Mandatory labeling of GM foods that are found to be safe is practised in the European Union, Japan and New Zealand.
Therefore, the correct answer is option C.

Which statement about genetically modified (GM) foods is false?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. Scientists have used genetic modification, in various forms, as a means of improving crop yields, crop quality, and pest resistance for many years.

  2. Genetic modification includes products made by artificial mutagenesis and by non-natural crosses between unrelated spscies.

  3. A major difficulty in labelling foods as GM-free is that it is virtually impossible to measure genetically modified DNA or protein molecules in most food made from GM crops.

  4. The recent decision by McCain foods to stop processing GM potatoes means that they will eventually use less pesticides to produce the potatoes that are required to make fries.

  5. A major environmental concern with GM crops is that engineered genes will escape into the environment, resulting in the origin of superweeds (aggressive undersirable plant species).

Show answer
Correct Option: D
Explanation:

McCain foods has decided to stop processing genetically modified potatoes, because of pressure from consumers who fear damage to the environment and human health. 

Thus, the correct answer is option C.

NaCl is harmful to most crop plants. A scientist at the University of Toronto genetically modified plant so that it could be grown in dry parts of the world where the available water has a high level of NaCl. This genetically modified plant crop with the high levels of NaCl by transporting salt into its vacuoles where it accumulates to abnormally high levels. Which feature would be observed in the genetically modified plant when compared to a non-modified plant?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. The leaves in the modified plant are more yellow in colour.

  2. The modified plant has salt crystals on the surface of its leaves.

  3. The cytosol (the material between the plasma membrane and the vacuole membrene, excluding the organelles) in the modified plant has a lower osmotic pressure.

  4. The cytosol in the modified plant has a higher osmotic pressure.

  5. The osmotic pressure is the same in both plants.

Show answer
Correct Option: D
Explanation:

In conditions of high salinity, an important mechanism to survive salt stress relies on the accumulation of excess cytoplasmic Na+ in vacuoles, reducing the amount in the cytoplasm and providing osmotic pressure. The transgenic plants accumulate more Na and K in their leaf tissue. The increased accumulation of sodium is due to the consequence of the activity of the vacuolar sodium proton antiporter. The net increase in the concentration of solutes in the cell leads to an increase in the uptake of water so that the transgenic plants can maintain turgor. 

Thus, the correct answer is option D.

Which statement about the foreign genetic material in genetically modified (GM) crop plants or animals is false?

botany biotechnology and genetic engineering stds and infertility gm crops biotechnology

  1. It must be inserted again in each generation.

  2. It alters the phenotype of the GM plant or animal.

  3. It may be subject to natural selection by weather, pests and diseases.

  4. It may be transferred to related non-crop plants or animals.

Show answer
Correct Option: A
Explanation:

A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. Genetic modification involves the mutation, insertion, or deletion of genes. Inserted genes usually come from a different species in a form of horizontal gene-transfer. Hence, the genetic material need not be inserted again in each generation.