The Fundamental Unit of Life 6 long answers Flashcards
What are plastids ?
Plastids are present only in plant cells. There are two types of plastids – chromoplasts (coloured plastids) and leucoplasts (white or colorless plastids).
Chromoplasts containing the pigment chlorophyll are known as chloroplasts.
Chloroplasts are important for photosynthesis in plants. Chloroplasts also contain yellow or orange pigments in addition to chlorophyll.
Leucoplasts are primarily organelles in which materials such as starch and protein granules are stored.
The internal organization of the Chloroplast consists of numerous membrane layers embedded in a material called the stroma.
Like the mitochondria, plastids also have their own DNA and ribosomes.
What are Vacuoles ?
Vacuoles are storage sacs for solid or liquid contents.
Vacuoles are small sized in animal cells while plant cells have very large vacuoles. The central vacuole of some plant cells may occupy 50-90% of the cell volume.
In plant cells vacuoles are full of cell sap and provide strength and rigidity to the cell.
Many substances are stored in vacuoles. These include amino acids, sugars and some proteins.
In single-celled organisms like Amoeba, the food vacuole contains the food items that the Amoeba has consumed.
