How does an Amoeba Obtain its Food?

Anjali Mishra logo

Anjali Mishra Content Writer-SME

Content Writer-SME

Amoeba has temporary arm-like projections that help in capturing food, changing shape and size, and acting as locomotion organs. An amoeba obtain its food through a process called endocytosis. There are two types of endocytosis- phagocytosis and pinocytosis.

Phagocytosis is a biological process through which a living cell engulfs or eats foreign particles. It is used by various cells as an important defense mechanism. The intake of fluids and small molecules by the cell through invagination of the cell membrane is called pinocytosis.

Thus, amoeba obtains its food through the process of endocytosis in which the amoeba engulfs its prey with the help of pseudopodia (false foot) and food vacuole. The food vacuole then fuses with lysosomes (organelles containing digestive enzymes) to break down the food and provide nutrients to the cell.

The process of endocytosis in amoeba is completed in five major steps- Ingestion, digestion, absorption, assimilation, and egestion.

  • Ingestion: The first step through which the amoeba obtains its food is ingestion. The amoeba engulfs the food through its pseudopodia and by forming a food vacuole.
  • Digestion: The breakdown of complex food particles into small digestible particles is done in this step. The step is catalysed by digestive enzymes present in amoeba. 
  • Absorption: The digested food is absorbed completely in this step. 
  • Assimilation: Like animals, amoeba also require energy to perform various specific functions like growth, movement and reproduction. For this they use the energy obtained from digested food.
  • Egestion: The final stage of nutrition in amoeba is excretion through which undigested foods are excreted by breaking the cell membrane.

Digestion in amoeba


Important Facts about Amoeba

Amoeba is an example of unicellular organism which belongs to the kingdom Protista. It is characterized by its ability to change its shape and move by extending and retracting pseudopodia, or temporary projections of cytoplasm

  • Some species of amoeba are pathogenic and can cause diseases in humans and other animals.
  • It is common in freshwater, soil, and aquatic environments and is an important component of many foods.
  • Pseudopodia in amoeba help it to perform specialized functions like movement and food intake.
  • It obtains their food through the holozoic mode of nutrition in amoeba.

Check out:

CBSE CLASS XII Related Questions

  • 1.
    Enlist three advantages of genetically modified plants.


      • 2.

        Given below are the diagrammatic representations of the replicating fork of DNA in E. coli. Study the diagrams and answer the questions that follow.

        (a) Which one of the three diagrams (i), (ii) or (iii) is the correct representation of the replicating fork of DNA replication? Explain your answer.
        (b) Name the enzyme used in E. coli to join the newly synthesised fragments of DNA.


          • 3.
            Given below are few statements with reference to the uterus in the female reproductive system:

              • The myometrium exhibits strong contractions during the delivery of the baby.
              • The uterus opens into the cervix through a narrow opening called vagina.
              • The cavity of the cervix and the vagina forms the birth canal.
              • The outermost layer of uterus is a thin membranous perimetrium.

            • 4.

              The following question is based on pollination. Study the figures carefully and answer the questions that follow.

              • Give the scientific terms for the processes taking place in Figures A and B respectively.
              • Mention two conditions necessary for the process occurring in Figure B.
              •  
                • [(i)] State one advantage and one disadvantage of the process occurring in Figure B. 
                  OR
                • [(ii)] Name one plant where, in some flowers only, the process in Figure B takes place and give the reason responsible for it.


                • 5.
                  Describe the structure and working of a sparged stirred-tank bioreactor.


                    • 6.

                      Study the given molecular structure of double-stranded polynucleotide chain of DNA and answer the questions that follow.

                      (a) How many phosphodiester bonds are present in the given double-stranded polynucleotide chain? 
                      (b) How many base pairs are there in each helical turn of double helix structure of DNA? Also write the distance between a base pair in a helix. 
                      (c) In addition to H-bonds, what confers additional stability to the helical structure of DNA?

                        Comments


                        No Comments To Show