Possibly a Great White or a DaggerNose
Answer:
Crossing over and random alignment are the events of meiosis-I that add new gene combinations to the gametes. Random fusion of male and female gametes is called random fertilization.
Explanation:
During the pachytene stage of meiosis-I, part of the chromatids of each of the homologous chromosomes of a bivalent is broken apart and exchanged. This exchange of the genetic material between the members of a bivalent is called crossing over. The recombinant chromatids formed by crossing over have new allele combinations that were otherwise not present in the parental chromatids.
During metaphase I, the homologous pairs are aligned at the cell's equator in a random manner. This means that either the paternal or maternal chromosome of a pair may face one or the other pole of the cell. The arrangement of chromosomes during metaphase-I determines whether the paternal or maternal chromosome of each pair would be distributed to one or the other pole of the cell. This random segregation creates new gene combinations in gametes.
All the gametes have equal chances of getting fused with a gamete from the opposite gender. This is called random fertilization and further adds variations.
Answer:
Climate change has the effect of determining migration of people.
Explanation:
A hazardous environment eg. changes in rainfall patterns, increase in temperature, sea level rise, cyclone frequency has the effect of people migrating to cooler places whereas a conducive environment has the effect of attracting more people to settle there.
Answer: Option A ,Band C.
Explanation:
Sympatric speciation is the evolution or isolation of new species from the original populations of species occupying in the same geographical area. Sympatric speciation commonly occur due to sexual selection of mates can cause reproductive barriers or isolation which keep gene pools separate. A plant with extra set of homologous chromosomes is an example of sympatric speciation.
The fertilizers used by farmers can have negative effects on aquatic ecosystems because there is every possibility that the runoffs from the fields can create an algal bloom in the nearby water body. This algal bloom can have a very negative effect on the living organisms of the aquatic body. I hope it helps.
