Answer:
The options are
A.Independent assortment
B. Mutation
C. Crossing over
D. Non disjunction
The answer is A.Independent assortment
Explanation:
Independent assortment of genes involves the separation of genes during the formation and development of reproductive cells.
A boy has XY chromosome and a lady has XX chromosomes. This explains why Sue inherited the mother's copy of chromosome 13 but their father's copy of chromosome 14 while her brother Billy inherited their father's copy of both chromosomes 13 and 14. He inherited both due to the presence of XY chromosomes.
Two scientists testing different hypotheses about the same question
Answer:
I found this from someone else. This is not my work, Also if this does not answer the question ask the question on here and you can see more answers. hope this helps.!
Explanation:
According to National Geographic, ostriches are a part of a very small group of birds that cannot fly because unlike most birds, their small wings are not strong enough to carry their body for flight and their breastbone isn't balanced enough for flying. Birds that are unable to fly are called ratites.
A number of scientists namely Thomas Huxley, Richard Owen, and others have tried to show that these ratites are actually related to each other and eventually, it was discovered that they all had one thing in common, the way the bones at the roof of the mouth were arranged was similar to that of reptiles rather than other birds.
Richard Owen found and assembled the remains of an extinct ostrich skeleton which was an extinct moa and contrary to already held opinion, one ratite known as tinamous did not really fit with the profile of a ratite because it could fly, even though almost grudgingly and they possessed keeled sternum which suggests that they evolved from flying birds.
DNA tests showed that tinamous evolved within ratites and not necessarily as a separate entity. The tests also showed that moas and tinamous are related.
It was also speculated that the division of the supercontinent Pangaea southern side led to the separation of flightless ratite ancestors, causing each landlocked group to evolve and become the flightless birds we know today such as the ostrich, rheas, etc.