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.
Answer:
The correct option is C: antigen-binding sites
Explanation:
The antibody is shaped much like the letter Y in the English alphabet. It has two antigen binding sites that are identical in nature. The specificity of these sites is determined by the amino acid sequence that makes it up. Antibodies are complementary to these antigen binding sites, and the antibodies have an incredible ability to recognize a great variety of antigens.
Hope that answers the question, have a great day!
First pic :
plants do not have cell membranes
(plants have BOTH cell membranes and cell walls)
second pic:
ATGC
(opposite strand of the DNA TACG)
third pic:
the second choice
(selectively permeable means only specific molecules could get in and go out)
fourth pic:
option 2
(cellular respiration takes sugar (or food) and makes it into ATP energy. this is what makes us have energy after we eat)
I really hope this helped :))
Answer:
D. unnatural scream
Explanation:
The Bigfoot is a an animal around there's lot of debate, as there are thousands of sightings, but not conclusive proof that it actually exists, thus it falls into the category of mythological creatures for the time being. This creature has been described by thousands of people that claim to have seen it or hear it, and the descriptions are pretty much the same, very tall, hominid-like, bipedal, dark fur, very quick, and terrifying. Something else that is a specific feature of the creature is the sounds its make, as everyone has said that it produces incredibly powerful unnatural sounding scream. People have said that they have frozen from fear after hearing those sounds, and that whenever that sound occurs all other animals run away frightened in the opposite direction.
The answer is uterus, well that's what I got
