Answer:
C. K+ ions flow out the the guard cells and water flows out the cells.
Explanation:
The turgidity of the guard cells allows the opening and closing of the stomata. This is especially necessary when it comes to water conservation in plants. In order for the cells to become turgid or flaccid, there must be the influx and out ward movement of water via osmosis.
In order for this the occur the osmotic pressure of the cellular environment must change and this is done by changing the solute concentration.
The pumping in of K+ ions out the cell allows the solute concentration to decrease and this in turn encourages the movement of water across a concentration gradient through a semi-permiable membrane.
The water leaves the guard cells and they become flaccid. This causes the stomata to be covered.
D. The cytoplasm slides and forms a pseudopodium in front to move the cell forwards.
Answer:
-Physical properties possessed by all stars:
- They are made of gases such as hydrogen and helium.
- They shine very brightly due to interaction of hydrogen and helium at appropriate pressure and temperature.
- They contain iron in their cores which monitors the fusion reaction.
- They make energy through fusion between the gases present in the stars which are hydrogen and helium.
- They are not spherical in shape hence this physical property is false in terms physical properties of the stars.
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Explanation:
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:
by looking at their physical features, the fossil record, and dna sequences
