Q: An artificial pacemaker is a device that regulates the beat of the heart by an electrical stimulus. Some early pacemakers were powered by batteries and were worn externally with wires passing through the skin to the surface of the heart. Modern pacemakers are now much smaller and are implanted surgically. Which most likely has increased the lifespan and effectiveness of artificial pacemakers?

OPTIONS:
- the development of thinner wires
- the invention of lithium batteries
- mass production of pacemaker parts
- reducing the cost of producing pacemakers
A: the invention of lithium batteries
Q: Which disease is correctly paired with the cause of the disease?

OPTIONS:
- athlete's foot - fungi
- malaria - viruses
- influenza - bacteria
- pneumonia - protists
A: athlete's foot - fungi
Q: A cell that is unable to import substances required to process chemical energy is most likely a result of a malfunctioning

OPTIONS:
- cell membrane.
- endoplasmic reticulum.
- Golgi body.
- nuclear envelope.
A: cell membrane.
Q: Over a long period of time, a rocky volcanic island that previously did not support any form of life got transformed into a dense forested region. Which of these species is most likely to have been the pioneer species that initiated this transformation?

OPTIONS:
- ferns
- grasses
- lichens
- mushrooms
A:
lichens