Correct answer: A). Earth’s average temperature will increase.
Green house gases are those gases, which are present in the air that have the ability to trap heat of the earth's surface. Gases like carbon dioxide and methane are known to be found naturally play an important role in earth's climate. If they are not found the earth' s climate would be too cold creating problem for survival of life on the earth.
They absorb and emit the radiation in the thermal infrared range. These gases act like a blanket and save earth surface from infrared radiation by absorbing them and prevent them from escaping out of the earth surface.
But due to increased in the concentration of green house gases like carbon dioxide and methane in the environment due to pollution and deforestation is causing a great problem, which result in a global warming, which is a great concern for all the people on the planet. It will increase the annual global temperature which will result in the melting of glaciers. So, the issue of global warming should be taken seriously and adequate measure should be taken to control it.
Answer:
B. The mutations were beneficial for each new environment.
Explanation:
Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
