non-disjunction is a pathological event that occurs during the second anaphase in meiosis when sister chromatids are not separated. As a result one of the resulting cells will have 1 extra chromosome and the other will be 1 short. An example of a non-disjunction that can occur in humans is Down syndrome that has a frequency of about 1/1000 people. It is caused by the non-disjunction of the 21st pair of chromosomes.
Answer:
Bullock cart
Explanation:
Bullock cart is an ancient means of transport which is still used in many places of world. Bullock cart is a two wheeled or four wheeled vehicle that is pulled by oxen.
Oxen are also used for ploughing. they carry plough in their back and the person directs the plough in the right direction.
Hence, the correct answer is "Bullock cart".
The change in weather pattern caused forest to become sparse and hot weather caused the reduction of apes as they had less food and difficulty in surviving the climate.
Explanation:
In Miocene epoch volcanic mountain chains were created in Central Africa which abruptly changed the local weather.
The sea-level got drop due to global cooling of that time.
This resulted in continental drift making land connection of Africa with Eurasia.
The primates started migrating through this route.
The African forest become dry causing selective pressures in primates.
The cooler climate in Eurasia caused extinction and migration of primates to Africa in late Miocene epoch.
The hot and humid climate and less woodland caused a reduction in number of apes which were replaced by modern world monkeys.