Energy is always lost as energy is moved from one level to another. ... The loss of energy due to the second law of thermodynamics results in a pyramid with a large base and a 10% ratio between levels.
Answer:
Osteoclasts are the type of cells which are responsible for the absorption of calcium from bones.
Explanation:
Osteoclasts is special type of cells which is released by parathyroid gland when the blood have low levels of calcium. Osteoclasts absorb calcium from the bones and add this calcium into the blood to increase the calcium level. If calcium is present in very high amount so this calcium is stored in the bones of the body and extracted when needed by the body.
Answer:
advantages of sexual reproduction:
it produces variation in the offspring
the species can adapt to new environments due to variation, which gives them a survival advantage
a disease is less likely to affect all the individuals in a population
disadvantages of sexual reproduction:
time and energy are needed to find a mate
it is not possible for an isolated individual
advantages of asexual reproduction
the population can increase rapidly when the conditions are favourable
only one parent is needed
it is more time and energy efficient as you don't need a mate
Disadvantages of asexual reproduction
it does not lead to variation in a population
the species may only be suited to one habitat
disease may affect all the individuals in a population
Explanation:
Answer:
Transmission electron microscope (MET): allows sample observation in ultra-thin sections. A TEM directs the electron beam towards the object to be increased. A part of the electrons bounce or are absorbed by the object and others pass through it forming an enlarged image of the specimen. To use a TEM, the sample must be cut into thin layers, not larger than a couple thousand thousands of angstroms. A photographic plate or a fluorescent screen is placed behind the object to record the enlarged image. Transmission electron microscopes can increase an object up to a million times.
A scanning electron microscope creates an enlarged image of the surface of an object. It is not necessary to cut the object into layers to observe it with an SEM, but it can be placed in the microscope with very few preparations. The SEM scans the image surface point by point, unlike the TEM, which examines a large part of the sample each time. Its operation is based on traversing the sample with a very concentrated beam of electrons, similar to the scanning of an electron beam on a television screen. The electrons in the beam can disperse from the sample or cause secondary electrons to appear. Lost and secondary electrons are collected and counted by an electronic device located on the sides of the specimen. Each point read from the sample corresponds to a pixel on a television monitor. The higher the number of electrons counted by the device, the greater the brightness of the pixel on the screen. As the electron beam sweeps the sample, the entire image of it is presented on the monitor. Scanning electron microscopes can enlarge objects 200,000 times or more. This type of microscope is very useful because, unlike TEM or optical microscopes, it produces realistic three-dimensional images of the object's surface.
If there were no patterns in nature everything would be complicated. Atoms and all the little things would be different meaning our body structures would be different and the plants would be different too.
