Answer:
Frederick Griffith was the first scientist who discovered that cell contains some components that can be transferred to another cell and cause a permanent change(transformation) in the new cell.
To prove this he performed an experiment in which he took two strains of <em>Streptococcus pneumoniae</em> which contain one rough strain and one smooth strain. Rough strain was non-virulent strain and smooth strain was virulent strain.
So he injected smooth and rough strain in mice and saw that mice die when virulent strain is injected and survive when non-virulent strain is injected. Then he injected heat killed virulent strain in which mice survived.
Then he added remain of heat killed bacteria with live smooth strain of bacteria and infected the mice and saw that the mice was killed by non-virulent smooth strain of streptococcus.
After this experiment he concluded that cells contain some component later identified as DNA which can be transferred to new population of cells and transform these new cells.
Answer:
The answer is D. Food security
Explanation:
Sustainable Agriculture:
Sustainable agriculture or farming is a combination of agricultural policies, practices and measures that yield the maximum profits and benefits without negatively impacting the environment.
Sustainable agriculture, as an idea, basically means to utilizes resources responsibly so that the future generations can reap the benefits as well.
Sustainable Farming Approaches:
Approaches to sustainable farming include policy as well as farming technique interventions. Some of these methods are:
- Crop rotations that involve planting diverse crops on a piece of land, as opposed to monoculture and intensive farming that gradually makes the soil nutrient deficient.
- Cover cropping after a season of monoculture to prevent leaving the soil bare til the next season.
- Use of renewable energy resources and integrated pet management to generate energy efficiently and minimize crop losses respectively.
Food Security:
Food security entails that healthy, nutritious and safe food is readily i.e. physically and economically available for all people. Food security is one of the major sustainability goals.
<span>The answer is True. Doppler Effect is defined as “the change( increase of decrease) found in wave, sounds or light as the soure and observer slowly walks away. Examples of this would be ripples formed when ducks are swimming in the lake or the sound of the sirens, going higher as they moved to another destination</span>
<span>C. more likely to have a gastrovascular cavity</span>
