Biology · Science General

Cell Biology and Structure

3,062 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

Organelles are membrane-enclosed structures that are found within the cells and each with a particular function. Some organelles possess their own genes. Which of the following organelles have their own DNA?

a. Lysosomes b. Mitochondria c. Plastids d. Cytoplasms

  1. a, b, c and d

  2. a, b and c

  3. a, b and d

  4. a and d

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

This is the correct answer. Mitochondria possess their own DNA and carry out some of their own protein synthesis. Chloroplasts are organelles that are found within the cells of plants and algae. Chloroplasts contain the pigment chlorophyll and are responsible for carrying out photosynthesis and contain their own DNA.

Multiple choice

Which of the following statements are correct about the cell theory as presented by Schleiden and Schwann?

a. All plants and animals are composed of cells. b. A cell is the basic unit of life. c. All cells arise from pre-existing cells. Many cells group together in a single body and assume different functions in it to form various body parts.

  1. a and b

  2. a, b and c

  3. a, b, c and d

  4. b, c and d

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

This is the correct answer as the cell theory as presented by Schleiden and Schwann points out that all plants and animals are composed of cells and that cell is the basic unit of life.

Multiple choice

A nucleolus originates from a:

  1. Lysosome

  2. Golgi complex

  3. Endoplasmic reticulum

  4. Chromosome

  5. Mitochondria
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Nucleolus originates from chromosome. It contains all the dna of the cell. It is used as instructions to create the building blocks of the cell(proteins). It is often refered to as the brain of the cell as it controlls what goes on. 

Multiple choice

The cells helping an individual to detect surface like rough vs. smooth are

  1. Schwann cells

  2. Pacinian corpuscles

  3. Kulchitsky cells

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

These are mechanoreceptor. They are nerve endings present in the skin which are responsible for perception to vibration and pressure. Vibrational role is used by an individual to detect surface like rough vs. smooth.

Multiple choice

The cells responsible for maintaining the blood brain barrier, forming a 3 D' framework for the central nervous system and including the repair work in damaged neural tissue is

  1. oligodendrocytes

  2. astrocytes

  3. ependymal cells

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

Astrocytes have many cytoplasmic processes terminating on blood vessels. These cells are engaged in all essential CNS functions, including blood flow regulation, maintaining the blood brain barrier, energy metabolism, ion and water homeostasis, immune defence of the body.

Multiple choice

The cells responsible for removing cell debris, wastes, and pathogens are

  1. microglia

  2. astrocytes

  3. oligodendrocytes

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

Microglia are regarded as the immune cells of the brain. After an injury, these cells undergo rapid change, altering their appearance, migrating to the site of the damage to help clear away and clean up dead, dying cells and cell debris.

Multiple choice

Which of the following features do not apply to a tissue?

  1. Tissues are absent in unicellular organisms.

  2. All the cells of a tissue are similar in structure.

  3. Tissues are present in animals only.

  4. Tissues are made up of cells specialized in one function.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

By definition, tissue is a group of cells, which have a similar structure and perform a common specific function. The tissues are present in both plants and hence, (3) is incorrect.