What is the primary reason for the different structures and functions of cells in an organism, despite all cells containing the same genetic material?

• Cells randomly develop different structures.

• Genes are selectively turned on or turned off in different cell types.

• Cells lose genetic material as they specialize.

• Environmental factors alone determine cell type.

What is the term for a single fertilized egg cell before it begins to divide?

• Embryo

• Blastocyst

• Zygote

• Gamete

Which characteristic best describes embryonic stem cells?

• They are specialized cells found in adult tissues.

• They are undifferentiated cells capable of becoming any cell type.

• They are only found in plants.

• They are responsible for repairing damaged organs in adults.

At what stage of human development does the process of cell differentiation typically begin?

• At birth.

• When the organism is a single-celled zygote.

• When the embryo consists of approximately eight cells.

• During adolescence.

What molecular process is primarily responsible for cell differentiation?

• Changes in the DNA sequence

• Selective activation and deactivation of genes in different cells

• Loss of chromosomes in specialized cells during development

• Random protein synthesis

How do adult stem cells differ from embryonic stem cells in terms of their differentiation potential?

• Adult stem cells can form any cell type, while embryonic stem cells are limited in what they become.

• Embryonic stem cells can form any cell type, while adult stem cells can only form a few cell types.

• Both adult and embryonic stem cells have the same unlimited differentiation potential.

• Adult stem cells are only found in adults, whereas embryonic stem cells are found in infants.

Which type of cells are continuously produced by adult stem cells found in bone marrow?

• Nerve cells.

• Muscle cells.

• Blood cells.

• Skin cells.

What is the main role of differentiation in adult humans?

• To create entirely new organs.

• To initiate the development of a new organism.

• To repair and replace damaged or old tissues and organs.

• To change the genetic code of existing cells.

Where are meristems, the regions containing plant stem cells, primarily located?

• In the leaves of the plant.

• In the tips of growing roots and shoots.

• Throughout the entire plant stem.

• Only in the flowers of the plant.

What agricultural technique utilizes plant stem cells from meristem tissues to grow entire new plants?

• Genetic modification

• Cross-pollination

• Tissue culture

• Selective breeding