Which of the following are some ethical issues associated with biotechnology?
1. Animals used for safety testing of drugs and vaccines suffer from great pain and discomfort.
2. Transgenic organisms used in research may have a negative impact on the wild population, if they are accidentally released.
3. Almost all the bacteria used in genetic engineering are pathogenic.
4. Herbicide resistance genes introduced into crops may be passed on to weeds.

The correct option is C 1, 2 and 4
Biotechnology is the genetic manipulation of living organisms which results in the production of products that are useful to mankind.
Even though biotechnology has several applications that benefits the mankind, it still gives rise to several ethical issues.
- Organisms with functional foreign genes introduced by genetic engineering are known as transgenic organisms. The national and international regulations require new drugs or vaccines to be tested on animals before being eligible for human use.
Transgenic animals are genetically engineered to increase their sensitivity to the pathogens. This helps to test the effectiveness of the drugs and vaccines, their side effects, dosages, etc. Apart from enduring pain and physical distress from the scientific procedures, the animals also suffer from the symptoms of the disease for which it is being studied. Most of these animals ultimately die in the process.

- Transgenic organisms used in research may have a negative impact on the wild population, if they are accidentally released. If a transgenic crop had some competitive advantage over the wild population it would compete for survival and persist in nature. This might eventually lead to complete extinction of the wild type variety and consequently disturb the ecological balance.

- Herbicide resistant genes engineered into crop plants may be transferred to weed varieties during cross pollination. This would render the weed varieties resistant to the herbicides and leading to their uncontrolled growth . They might compete with the crop plants for resources which might eventually lead to their extinction.

- One of the possible risks of genetic engineering is the accidental production of antibiotic resistant pathogenic bacteria by the insertion of antibiotic resistant genes. But scientists refuse such objections because most of the bacteria used in genetic engineering are non-pathogenic and their use is not expected to cause considerable harm.