The answer is D! living things are made up of units called cells.
Answer:
Explanation:
The resolving power of the microscope is dependent upon the objective lens. It can be measured by the ability of the lens to differentiate between the two lines or points on the specimen under observation. The more the resolving power the smaller will be the distance between the two lines or points that can be distinguished.
The following are the two ways that can be used to enhance the resolving power on the microscope:
Using a lens that has a higher aperture.
Decreasing the amount of light being entered into the microscope that means using light of less wavelength.
Explanation:
Psi packaging Element is a cis-acting RNA element identified in the genomes of the retroviruses Human immunodeficiency virus (HIV) and Simian immunodeficiency virus (SIV) It is involved in regulating encapsidation of the retroviral RNA, an essential step in replication.
Answer:
paracrine signaling.
Explanation:
Chemical signaling between cells is one of the most important ways that activities of tissues and organs are coordinated. The nervous system is the other major coordinating system in animals, but even here chemical signaling is used between adjacent neurons. The mechanisms involved are described as either being paracrine, autocrine, intracrine, endocrine, neuroendocrine or pheromones. Paracrine signals diffuse locally and act on neighboring cells.
