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

The subunits of a prokaryotic ribosome are

  1. 60S and 40S

  2. 50S and 30S

  3. 60S and 50S

  4. 20S and 15S
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The subunits of a prokaryotic ribosome are 50S and 30S. The 70S ribosomes of prokaryotes have in the larger 50S subunit, 23S and 5S types of rRNA and 34 different proteins. The 30S subunit contains a molecule of 16S rRNA and 21 different proteins.

Multiple choice

Movement of cytoplasm is termed as

  1. Brownian movement

  2. Endocytosis

  3. Cyclosis

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

 This option is correct because the movement of cytoplasm is termed as cyclosis or cytoplasmic streaming.

Multiple choice

Which of the following options is the smallest basic unit of life in living organisms?

  1. Compound

  2. Cell

  3. Nucleus

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

The smallest basic unit of life in living organisms is the one, which is able to perform all the functions of life independently, i.e. the cell. Nucleus and mitochondria are cell organelles which cannot independently carry the functions of life. Compound is a substance made by chemical combination of the atoms. 

Multiple choice

Which instrument is used to see cells?

  1. Telescope

  2. Microscope

  3. Endoscope

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

Microscope is the instrument used to see larger view of the small sized structures. Endoscope is the instrument with a light attached to see inside the body cavity. Telescope is the instrument used to see remote objects. Stethoscope is the instrument used by doctors to check a person’s heartbeat.

Multiple choice

Prokaryotic ribosomes are

  1. 70 S

  2. 80 S

  3. 55 S

  4. 40 S
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The ribosomes of prokaryotic cells are smaller than eukaryotic ribosomes. Prokaryotic ribosomes measure 70 S units.

Multiple choice

Peroxisomes are involved in

  1. DNA replication

  2. translation of m-RNA

  3. photorespiration

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

 Peroxisomes contain enzymes for photorespiration which occur when carbon-dioxide level is low and RUBP is oxygenated to form phosphoglycolate and 3-phosphoglycerate.

Multiple choice

Calvin cycle takes place in the

  1. stroma of chloroplasts

  2. cristae of mitochondria

  3. nuclear membrane

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

Calvin cycle of photosynthesis occurs in the stroma of chloroplasts to produce glyceraldehyde-3-phosphate.