Final answer:
Null mutations in crucial "genes" involved in regulating cell survival or apoptosis can be fatal during embryonic development, leading to the death of the organism. Mutations such as those in the p53 gene might lead to cancer or, in other instances, can cause dominant lethal inheritance patterns that significantly affect an organism's lifespan.
Step-by-step explanation:
Null mutations in genes that regulate cell survival or apoptosis can lead to the death of cells that should normally survive. This is crucial during embryonic development, where cells undergo apoptosis to shape structures such as fingers and toes. The death of developing organisms can result from mutations in essential genes, where a delicate balance is required to maintain the right amount of cell growth and death.
For instance, the p53 gene is vital for monitoring DNA damage and can initiate cell repair or cell death if necessary. A mutation in p53 can prevent it from functioning properly, leading to uncontrolled cell division, or cancer, due to the accumulation of further mutations. However, in some instances, such as with p53 in elephants, multiple copies of the gene can provide a safeguard against these detrimental mutations.
Dominant lethal inheritance patterns show that certain mutations can cause such severe consequences that the organism does not survive past embryonic development or has a greatly shortened lifespan. A prime example is Huntington's disease, which is caused by a dominant lethal allele and results in the degeneration of nerve cells. While mutations can have drastic effects on survival and development, they can occasionally lead to beneficial adaptations that aid an organism's survival in a given habitat.