There are specific checkpoints in the cell cycle that ensure the cell is ready to proceed to the next stage. A cell has just finished replicating its DNA. A protein called p53 checks the DNA for damage before allowing the cell to enter mitosis. At which checkpoint is this check most likely to occur?

In the electron transport chain of cellular respiration, electrons are passed from molecule to molecule. When the molecule NADH gives up its electrons and becomes NAD+, what has happened to NADH?

Carbon-14 is a radioactive isotope of carbon used in carbon dating. The number 14 refers to the total number of protons and neutrons in the atom’s nucleus. Given that the atomic number of carbon is 6, how many neutrons does carbon-14 have?

In a healthy cell, the cell cycle is regulated by checkpoints that prevent the cell from dividing if there is DNA damage. In a cancerous cell, this regulation is often lost. What is a key difference in the way a cancerous cell divides compared to a healthy cell?

In a eukaryotic cell, the process of cellular respiration begins with glycolysis, which takes place in the cytoplasm. What is the next stage and where does it take place?

A pedigree chart shows a genetic disorder that is X-linked recessive. The mother is a carrier, and the father is not affected. What is the probability that their son will be affected with the disorder?

The element sodium (Na) has an atomic number of 11. How many protons are in a neutral atom of sodium?

A scientist is studying a virus and a bacterium. The bacterium is able to maintain a stable internal environment and uses energy from its surroundings to grow. The virus, on the other hand, cannot maintain its own internal environment and can only reproduce by hijacking a host cell. Based on these observations, which of the following is true?

In a healthy cell, tumor suppressor genes, like p53, are responsible for stopping cell division when there is DNA damage. However, in some cancer cells, these genes are silenced. What epigenetic modification can lead to the silencing of tumor suppressor genes?

A bacterial cell is performing cellular respiration to produce energy. Where do the processes of glycolysis and the citric acid cycle occur in this cell?