3.8.2.1 Most of a cell’s DNA is not translated

What are totipotent cells capable of?

• Maturing into only muscle cells

• Maturing into any type of body cell

• Maturing into only nerve cells

• Maturing into only blood cells

Answer explanation

Totipotent cells can differentiate into any type of body cell, including muscle, nerve, and blood cells. This ability makes them unique compared to other cell types that are limited to specific lineages.

During development, what happens to totipotent cells?

• They translate all of their DNA

• They translate only part of their DNA

• They do not translate any DNA

• They lose their DNA

Answer explanation

Totipotent cells have the ability to differentiate into any cell type. During development, they translate only part of their DNA, activating specific genes necessary for their current function while keeping others inactive.

For how long do totipotent cells occur in mammalian embryos?

• Throughout the entire life of the organism

• Only for a limited time

• Only during adulthood

• Only during old age

Answer explanation

Totipotent cells are present only during the early stages of embryonic development, specifically in the zygote and the first few divisions. They can differentiate into any cell type but are not maintained throughout the organism's life.

Which type of stem cells can divide in unlimited numbers?

• Unipotent stem cells

• Pluripotent stem cells

• Totipotent stem cells

• Multipotent stem cells

Answer explanation

Pluripotent stem cells can divide indefinitely and differentiate into almost any cell type, making them unique among stem cells. In contrast, unipotent, multipotent, and totipotent stem cells have more limited division and differentiation capabilities.

What is an example of unipotent cells?

• Neurons

• Cardiomyocytes

• Skin cells

• Blood cells

Answer explanation

Cardiomyocytes are unipotent cells, meaning they can only differentiate into one cell type, which is heart muscle cells. In contrast, neurons, skin cells, and blood cells have more diverse differentiation potential.

What can induced pluripotent stem cells (iPS cells) be produced from?

• Totipotent cells

• Pluripotent cells

• Unipotent cells

• Multipotent cells

Answer explanation

Induced pluripotent stem cells (iPS cells) can be produced from unipotent cells, which have the ability to differentiate into a single cell type. This process reprograms them to a pluripotent state, allowing them to become any cell type.

What is required to produce iPS cells from unipotent cells?

• DNA replication

• Protein transcription factors

• RNA interference

• Gene deletion

Answer explanation

To produce iPS cells from unipotent cells, specific protein transcription factors are required to reprogram the cells. These factors activate genes that induce pluripotency, allowing the cells to revert to a stem cell-like state.

Which type of cells are found in mature mammals and can form a limited number of different cell types?

• Totipotent cells

• Pluripotent cells

• Multipotent cells

• Unipotent cells

Answer explanation

Multipotent cells are found in mature mammals and can differentiate into a limited range of cell types, unlike totipotent and pluripotent cells, which can form more diverse cell types.

What is the primary use of pluripotent stem cells in medicine?

• Treating human disorders

• Enhancing athletic performance

• Increasing lifespan

• Improving memory

Answer explanation

Pluripotent stem cells can differentiate into any cell type, making them crucial for treating human disorders by regenerating damaged tissues and organs, unlike the other options which are not primary medical uses.

Which of the following is NOT a characteristic of pluripotent stem cells?

• Can divide in unlimited numbers

• Can mature into any type of body cell

• Can only form one type of cell

• Can be used in treating human disorders

Answer explanation

Pluripotent stem cells can differentiate into nearly any cell type, not just one. Therefore, the statement "Can only form one type of cell" is incorrect and does not describe a characteristic of pluripotent stem cells.