Tag: botany

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Questions Related to botany

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

A student wants to study the metaphasic behaviour of chromosomes in a living cell. The technique most suitable is

  1. Phase-contrast microscope.

  2. X-ray microscope.

  3. Cell fractionation.

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

Phase contrast microscopy is a type of microscopic technique which converts phase shifts in light passing through a transparent specimen to brightness changes in the image. This technique made possible to study living cells without staining.

Hence A is the correct option. 

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

High wavelength UV rays are used in

  1. Fluorescent microscope.

  2. Polarising microscope.

  3. Ultraviolet microscope.

  4. Phase-contrast microscope.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fluorescent microscope is a modification of ultraviolet microscope, which was made by Coons. The instrument uses long wave ultra violet rays for illumination. The microscope is useful in detecting those components which show autofluorescence, e.g., chlorophyll, collagen fibrils, vitamin A.

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

The types of lenses in a compound microscope are

  1. $3$.
  2. $4$.
  3. $2$.
  4. $1$.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
There are three main types of optical telescopes; refractive, reflective, and catadioptric. Refractive telescopes, such as the one invented by Galileo, use an objective lens and an eyepiece.
So the correct option is A. 
Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

A living cell is to be studied without staining. A microcsope that can be used for this is

  1. Phase contrast microscope

  2. TEM

  3. SEM

  4. Fluorescent microscope
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Option $ -(A) $ Phase contrast microscope
It is an optical microscopy technique that converts phase shifts in light passing through a transparent specimen to brightness changes in the images.
Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Distribution of two or more specific molecules within a cell is studied by _______________.

  1. Fluorescent microscope.

  2. Dark field microscope.

  3. Bright field microscope.

  4. Phase contrast microscope.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The fluorescence microscope can localize and quantify specific molecules in the cells. It is the most versatile and powerful technique for localizing proteins within a cell by light microscopy, is fluorescent staining of cells and the observation in the fluorescence microscope.
Thus, the correct answer is option A. 
Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

A chemical substance irradiated with ultraviolet rays emits visible light. What is it called?

  1. Luminescent

  2. Bioluminescent

  3. Fluorochrome

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

A fluorochrome is a chemical compound that can re-emit light upon light excitation, a process known as fluorescence. This is the fundamental principle used in fluorescence microscopy.

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

A major breakthrough in the studies of cells came with the development of electron microscope. This is because

  1. Electron microscope is more powerful than the light microscope as it uses a beam of electrons which has wavelength much longer than that of photons.

  2. Resolution power of electron microscope is much higher than that of light microscope.
  3. Resolution power of electron microscope is $200-350$nm as compared to $0.1-02$nm for the light microscope.

  4. Electron beam can pass through thick materials whereas light microscopy requires thin sections.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The electron microscope provides much higher resolution than a light microscope because electrons have a much shorter wavelength than visible light photons, allowing for the visualization of much smaller structures.

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.