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.
There are options for this question they are:
a) neutral stimulus; conditioned stimulus
b) conditioned stimulus; neutral stimulus
c) unconditioned stimulus; conditioned stimulus
d) neutral stimulus; unconditioned stimulus
e) unconditioned stimulus; neutral stimulus
The correct answers are - In this example, the buzzer begins as the neutral stimulus and eventually becomes the conditioned stimulus. The buzzer initially is a neutral stimulus because it have no role to play in the blinking response. Eventually though through learned association the buzzer becomes a conditioned stimulus because you now associate it with a puff of air to the eye which in turn causes you to blink.
It is true they do have internal fertilization. This is also one of the reason why it is easy to differentiate between a male or a female shark on birth due ot internal fertilization. <span />
"Mechanical" would be the kind of reproductive isolation among the choices given in the question that has been observed in these two species. The correct option among all the options that are given in the question is the first option or option "A". I hope that the answer has come to your help.
