Biological Resources Booklet

Study Notes

Glasshouses and polythene tunnels offer protection from harsh weather, enhancing crop yield.
Controlled conditions allow for monitoring factors such as temperature and humidity, favorable for sensitive crops like tomatoes, lettuce, and strawberries.
Increased carbon dioxide levels and warmer temperatures inside glasshouses boost photosynthesis, directly impacting crop yields.

Fertilizers supply essential mineral ions for optimal plant growth.
Mineral ions are absorbed through the roots via active transport and transported through the xylem with water.
Key mineral ions:
- Magnesium ions: Essential for chlorophyll production.
- Nitrates: Necessary for amino acid formation, supporting protein synthesis and growth.
- Phosphates: Important for energy production and genetic material synthesis.
- Potassium ions: Activate enzymes for various plant processes.

Pest control is crucial for protecting crops from damage and maximizing yield.
Biological control is selective; for example, ladybirds specifically target aphids without harming other beneficial insects.
Chemical pesticides, while effective, are not selective, potentially killing non-target organisms and posing environmental risks due to persistence.
Biocontrol methods do not accumulate in the environment, reducing long-term ecological impacts.

Selective breeding enhances plant and animal characteristics to develop desirable traits.
Genetic modification uses restriction enzymes to cut DNA at specific sites and ligase enzymes to join DNA segments.
Plasmids and viruses serve as vectors for inserting recombinant DNA into host cells, facilitating genetic modifications.

Micropropagation involves growing explants in vitro to produce commercial quantities of genetically identical plants with desirable traits.
Cloned mammals are created by introducing a diploid nucleus from a mature cell into an enucleated egg cell, exemplified by Dolly the sheep.
Cloned transgenic animals can be engineered to produce human proteins, demonstrating the practical applications of cloning in biotechnology.