Answer:
Molecular genetic approaches to the study of plant metabolism can be traced back to the isolation of the first cDNA encoding a plant enzyme (Bedbrook et al., 1980), the use of the Agrobacterium Ti plasmid to introduce foreign DNA into plant cells (Hernalsteens et al., 1980) and the establishment of routine plant transformation systems (Bevan, 1984; Horsch et al., 1985). It became possible to express foreign genes in plants and potentially to overexpress plant genes using cDNAs linked to strong promoters, with the aim of modifying metabolism. However, the discovery of the antisense phenomenon of plant gene silencing (van der Krol et al., 1988; Smith et al., 1988), and subsequently co‐suppression (Napoli et al., 1990; van der Krol et al., 1990), provided the most powerful and widely‐used methods for investigating the roles of specific enzymes in metabolism and plant growth. The antisense or co‐supression of gene expression, collectively known as post‐transcriptional gene silencing (PTGS), has been particularly versatile and powerful in studies of plant metabolism. With such molecular tools in place, plant metabolism became accessible to investigation and manipulation through genetic modification and dramatic progress was made in subsequent years (Stitt and Sonnewald, 1995; Herbers and Sonnewald, 1996), particularly in studies of solanaceous species (Frommer and Sonnewald, 1995).
<h3><u>Answer;</u></h3>
A. counterclockwise toward the center
<h3><u>Explanation;</u></h3>
- <em><u>In the Northern Hemisphere, winds associated with a low-pressure system blow in a counterclockwise direction towards the center, while those that are associated with a high-pressure system blow in clockwise direction outwards from the center.</u></em>
- In the Southern Hemisphere on the other hand, winds that are associated with a low-pressure system blow clockwise towards the center.
- <em><u>The rotation of the earth creates a force called the Coriolis force, which gives the wind that is within high pressure systems a clockwise circulation in the northern hemispheres and a counterclockwise circulation in the southern hemisphere.</u></em>
The 10% rule means that when energy is passed in an ecosystem from one trophic level to the next, only 10% of the energy will be passed on.
Phylum, it is the second largest group.
