Q. Which of the following is true about the cells in a multicellular organism?
- The cells contain different genes and therefore express different genes.
- The cells contain different genes, so they express only the genes they have in common.
- The cells contain the same genes but do not express the same genes.
- The cells contain the same genes and express the same genes.
Answer: The cells contain the same genes but do not express the same genes.
Multicellular organisms are organisms that consist of more than one cell, in contrast to unicellular organisms.
All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus Dictyostelium.
An animal or plant starts its life as a single cell—a fertilized egg. During development, this cell divides repeatedly to produce many different cells in a final pattern of spectacular complexity and precision. Ultimately, the genome determines the pattern, and the puzzle of developmental biology is to understand how it does so.
The genome is normally identical in every cell; the cells differ not because they contain different genetic information, but because they express different sets of genes. This selective gene expression controls the four essential processes by which the embryo is constructed:
Multicellular organisms are organisms that consist of more than one cell, in contrast to unicellular organisms.
All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus Dictyostelium.
An animal or plant starts its life as a single cell—a fertilized egg. During development, this cell divides repeatedly to produce many different cells in a final pattern of spectacular complexity and precision. Ultimately, the genome determines the pattern, and the puzzle of developmental biology is to understand how it does so.
The genome is normally identical in every cell; the cells differ not because they contain different genetic information, but because they express different sets of genes. This selective gene expression controls the four essential processes by which the embryo is constructed:
(1) cell proliferation, producing many cells from one,
(2) cell specialization, creating cells with different characteristics at different positions,
(3) cell interactions, coordinating the behavior of one cell with that of its neighbors, and
(4) cell movement, rearranging the cells to form structured tissues and organs
In a multicellular organism, the cells contain the same genes but do not express the same genes.
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