PART 1
1. The answer is low frequency electromagnetic waves are able to go around obstacles due to their larger wavelengths. This characteristic of lower frequency waves is due to their ability to diffract around obstacles such as buildings and hills. Therefore, they transmit over long distances unlike high frequency electromagnetic waves.
2. One disadvantage is interference. Electromagnetic waves of the same frequency transmitted at the same time will interfere with one other and therefore the signal will be lost or scrambled. Other electromagnetic waves such as microwaves are affected (interfered with) by weather elements.
3. Analogue signals are continuous signals with wave-like properties while digital signals are discrete signals or pulse (ons (1s) and offs (0s) that represent bits). Analogue signal is represented by a sine-wave while digital signal is represented by discrete squares waves.
4. Digital signals are less immune to eavesdropping unlike analogue signals. Analogue signal is also more prone to distortion unlike digital signal. Digital signals transmit more data than analogue signals. Digital signal draw less energy to transmit compared to analogue signal.
5. Broadcasting of TV is nowadays using digital signals due to the high number of available channels. Computers and the interne utilize digital signaling to transmit data. Controls systems such as radar system also use aspects of analogue waves. Sensors also utilize analogue waves especially transducers such as seismology equipment.
PART 2
1. One way is by sending radio waves to probes sent out in space to give them commands during exploration. Radio telescopes also pick up naturally-occurring radio waves from space and analyze the data to make conclusions about space and the astronomical objects.
2. Radio waves are used in communication by transmitting data over long distances. One example is its use TV transmission. Another is through military defense of airspace. The radio waves are used to detect enemy intrusion into restricted airspaces using radar.
3. It is common that signal from the environment will be in analogue signal format. The conversion to digital signals allows for the digital equipment in the telescope to interpret and analyze the data. Telescopes prefer digital equipment because they consume less power, handle more data, and are less prone to intrusion, and distortion, hence more secure to analogue equipment.
Answer:
The grazing food chain
Explanation:
There are two kinds of food chains one starting with autotrophs, the grazing food chain, and the other starting with dead organic matter, the detrital food chain.
Bioaccumulation is the process by which chemicals are stored in the tissues of living organisms. It is the accumulation of chemicals in the tissue of organisms through any route including, respiration, ingestion or direct contact with contaminated water, sediment and pore water in the sediment. These chemical substances include, pesticides or other chemicals.
Answer:
Option A.
Explanation:
Air pressure decreases with increasing altitude.
Answer: Flower color is an inherited trait, and the F1 and F2 phenotypes of the flowers arising from the pink and white cross can best be explained by another gene product that influences the
phenotypic expression.
Explanation: