The answer would be -2 and positive 6 because -2*6=-12 and -2+6=4
nothing else exept water and animals that can be used for food or entertainment like the zoo
Ans.
Different barriers present in the body prevent entry of disease causing agents or pathogens from entering into body and provide protection against them. These barriers include various physical, chemical, and biological barriers.
Physical barrier include skin and coughing and sneezing. Skin provides first line of defense by preventing entry of pathogens, and coughing and sneezing that expels harmful agents out of the body.
Chemical barriers include lysozyme, acids, and oil secretion. Lysozyme is an enzyme that kills bacteria by targeting their cell wall, while oil and acid prevent microbial growth by providing non-favorable environment for them.
Biological barriers include phagocytes and Langerhans cells. Phagocytes are immune cells that engulf and destroy pathogens and Langerhans cells are antigen-presenting cells that help in elimination of pathogens.
Answer:
Please find the detailed explanation/description on how to use the light microscope to view a wet mount of a protist. The 9 structures mentioned in the question are in CAPS.
Explanation:
- Firstly, the slide containing the wet mount of the protist is prepared and placed at the centre of a lowered STAGE. The STAGE CLIPS over the sides of the slide are used to hold it in place.
- The revolving turret or nosepiece is turned so that the LOWEST POWER OBJECTIVE LENS is in position i.e. directly above the sample/slide. The SCANNING OBJECTIVE LENS, the lowest objective lens with power of 4x is used initially.
- The slide is viewed through the EYEPIECE, and the image is brought into focus using the STAGE KNOBS.
- The COARSE FOCUS KNOB is turned until the protist on the slide is brought into broad focus. The FINE FOCUS KNOB is then used to bring the image on the slide into sharp focus.
N.B: The OBJECTIVE LENS should not touch the cover slip on the slide during this process.
- When the protist on the slide is clear using lowest power objective lens, the revolver turret can be rotated to allow HIGHER POWER OBJECTIVE LENS.
- Due to higher magnification of the HIGH POWER OBJECTIVE LENS, the protist might need to be refocused using the FOCUS KNOBS.
