No because Y chromosome never occur in females
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).
Answer:
True
Explanation:
The Chesapeake Bay is an example of an estuary that is located in the United States. It is a source of edible marine creatures such as oysters, crabs, prawns e.t.c
Over the years, non - sustainable harvesting of oysters by farmers have been happening at Chesapeake bay, resulting in a reduction in the amount of oysters present.
The pyramid of biomass represents a range of food webs found in one trophic level
A pyramid of biomass refers to graphical representation of biomass that is present per unit area of all the various trophic levels of the ecosystem.
<h2>Further Explanation</h2>
The graphical representation shows the relationship between biomass and trophic level that quantify the biomass that is present in each trophic level of energy community at a given period of time.
There are two types of pyramid of biomass, they include
- Inverted pyramid of biomass
- The upright pyramid of biomass
Inverted pyramid of biomass: a very good example of inverted pyramid can be seen in a case of pond ecosystem, where major producers in the ecosystem (mass of phytoplankton) will be lower than the mass of heterotrophs, such as insects.
The upright pyramid: The first thing on the upright pyramid is the producers, such as plants. The plants are present at the bottom level of the pyramid and followed by consumers.
Within the pyramid, the highest level is occupied by the carnivores; they are the lowest quantified amount of biomass. In upright pyramid the total weight of the producers is far more than when the weights of all the consumers are combined.
However, the main issues with the pyramid of biomass are that every trophic level of the pyramid seems to have more energy than it does.
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KEYWORDS:
- pyramid of biomass
- trophic level
- consumers
- graphical representation
- ecosystem
