Tag: cell and its discovery

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Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

In light microscope which lens does not take part in image formation?

  1. Objective$(5X)$
  2. Objective$(45X)$

  3. Condenser(D)

  4. Ocular
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a standard light microscope, the condenser is used to focus light onto the specimen, but it does not contribute to the magnification or the formation of the final image seen by the eye, unlike the objective and ocular lenses.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Robert Hooke used the ................... to look at the cells for the first time.

  1. Light microscope

  2. Dark field microscope

  3. Transmission electron microscope

  4. Scanning electron microscope
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Robert Hooke famously used a primitive compound light microscope to observe thin slices of cork, where he first identified and named the structures as cells.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

The conjugation of antibodies with which of the following is useful in fluorescence microscopy?

  1. Metal ions

  2. Dyes

  3. Carbohydrates

  4. Lipids
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In immunofluorescence, antibodies are conjugated with fluorescent dyes (fluorophores) to detect specific antigens within a sample under a fluorescence microscope.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Dry weight of macromolecules like RNA, proteins and DNA can be known through which method?

  1. Fluorescent microscopy

  2. Dark field microscopy

  3. Phase contrast microscopy

  4. Differential interference contrast microscopy.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Differential interference contrast (DIC) microscopy is often used to study the physical properties of biological samples, including mass and density, which can relate to the dry weight of cellular components.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Which of the following statements is not true?

  1. Fluorescent microscopy uses normal light to view molecules.

  2. Immersion oil increases refractive index.

  3. Electron microscope uses electromagnetic lenses.

  4. Scanning tunneling microscope is used for scanning computer chips for defects.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fluorescence microscopy does not use normal (white) light to view molecules; it uses specific excitation wavelengths (often UV or blue) to trigger fluorescence emission, making option A the false statement.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

The resolving power of a compound microscope will enhance with

  1. Increase in both wavelength of light and numerical aperture.

  2. Decrease in both wavelenth of light and numerical aperture.

  3. Decrease in wavelength of light and increase in numerical aperture.

  4. Increase in wavelength of light and decrease in numerical aperture.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The resolving power of a compound microscope can be defined as the ability of the microscope to form separate images of two objects placed very close to each other.
The resolving power of the compound microscope will increase with a decrease in wavelength of light and an increase in the numerical aperture.
So, the correct answer is 'Decrease in wavelength of light and an increase in the numerical aperture'.
Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Magnifying glasses were used for studying living beings for the first time by _________________.

  1. Galileo Galilei.

  2. Gesner.

  3. Faber.

  4. Leeuwenhoek.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Galileo Galilei is widely recognized for improving and using magnifying lenses (telescopes and microscopes) to study biological and astronomical objects in the early 17th century.