Biology · Science General

Cell Biology and Structure

3,221 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

Multiple choice

Which of the following is the preparation method particularly useful for examining lipid membranes and their incorporated proteins in Electron Microscopy?

  1. Cryofixation

  2. Chemical fixation

  3. Conductive coating

  4. Embedding

  5. Freeze-etch
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Freeze-fracture or freeze-etch – a preparation method particularly useful for examining lipid membranes and their incorporated proteins in face on view. The fresh tissue or cell suspension is frozen rapidly (cryofixation), then fractured by simply breaking or by using a microtome while maintained at liquid nitrogen temperature. The cold fractured surface (sometimes etched by increasing the temperature to about −100 °C for several minutes to let some ice sublime) is then shadowed with evaporated platinum, or gold at an average angle of 45° in a high vacuum evaporator

Multiple choice

Which of the following is used to study the movement of cell constituents during cell division, cell migration and movement of other cell structure within the cell?

  1. Photobleaching and video recording

  2. Micromanipulator and video recording

  3. Microcinematograpghy and video recording

  4. Graticule and video recording

  5. Ultramicrotome and video recording
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Microcinematography (time-lapse motion pictures) and video recording used to study of movement of cell constituents during cell division, cell migration and movement of other cell structure within the cell.

Multiple choice

Cell wall is made of cellulose. Which of the following is/are the function(s) of a cell wall?

a. It carries out metabolism. b. It protects the plant cell. c. It gives the plant cell a fixed shape. d. It makes the plant cell rigid. e. It holds air, water and particles of food.

  1. Only b, c and d

  2. Only e

  3. Only a and b

  4. Only a, b and e

  5. Only c, d and e
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. The cell wall protects the plant cell, gives the plant cell a fixed shape and makes the plant cell rigid.

Multiple choice

Which of the following statements is/are false?

a. Scleiden, in 1665, used a microscope to investigate the structure of a thin slice of cork. b. Cell theory states that the basic unit of structure and function of all living organisms is the cell. c. Cells obtain their energy in a process called respiration by burning food like glucose.

  1. Only b

  2. Only a

  3. Only a and b

  4. Only c

  5. Only b and c
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct option as this statement is false. Robert Hooke, in 1665, used a microscope to investigate the structure of a thin slice of cork. Scleiden, in 1838, suggested that all plants are made up of cells.

Multiple choice

Chemoautotrophs are those organisms which

  1. Use inorganic chemicals to manufacture nutrient molecules

  2. Use organic chemicals like glucose to manufacture nutrient molecules

  3. Obtain and utilize geothermal energy

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The residents of deep-sea hydrothermal vents obtain energy from inorganic chemicals surrounding them. Bacteria, for example, extract energy from the chemical bonds of hydrogen sulphide (H2S) and then add the freed hydrogens to carbon dioxide to synthesize organic nutrient compounds. Organisms like these, which use inorganic chemicals to manufacture nutrient molecules, are called chemoautotrophs.

Multiple choice

Which of the following statements is not true about human skin?

  1. The epidermal layer of skin contains many cells and blood vessels.

  2. Dermis layer is made up of connective tissue.

  3. Dermis contains apocrine,sebaceous,sweat glands and blood vessels

  4. Fibroblasts and adipocytes are found in the hypodermis of skin.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 The epidermis does not contain blood vessels