Answer:
B) Two different species of bacteria can share DNA, including antibiotic-resistance genes, during conjugation.
Explanation:
Conjugation is a process by which bacteria can exchange their genetic material between them. So through conjugation, the antibiotic-resistant gene coded by plasmid can be transferred through sex pilus to another bacteria.
So due to conjugation two different species of bacteria can share DNA which can include antibiotic-resistant genes. Therefore, through conjugation genetic variation and evolution are favored in bacteria. So due to this reason conjugation is a very important process in bacteria to spread antibiotic-resistant genes.
The answers to these questions are the following:
1. uses memory cells to fight off an infection from a pathogen: it is a specific response
2. evident by a sneeze, cough, fever, or other physical symptom: it is a non-specific response
3. recognizes antigens present on pathogens and attacks the pathogen with antibodies: it is a specific response
4. builds immunity to specific diseases that had previously entered the body: it is a specific response
5. does not target specific pathogens: it is a non-specific response
Explanation:
Structures that have lost their use through evolution are called vestigial structures. They provide evidence for evolution because they suggest that an organism changed from using the structure to not using the structure, or using it for a different purpose..
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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.
