Amniocentesis or amniotic fluid test or AFT refers to the prenatal diagnosis of chromosomal abnormalities and fetal infections. It is performed after 16 weeks of pregnancy. The fetal DNA from a small amount of cells from the amniotic fluid of the amniotic sac is sampled for genetic abnormalities by inserting a needle and extracting it. The fluid contains cells that are sloughed off by the fetus. They are separated from the amniotic fluid, grown in a culture and then microscopically examined for genetic and chromosomal abnormalities. The test is a reliable indicator of chromosomal abnormalities such as Down’s syndrome, spina bifida, muscular dystrophy, rh diseasetrisomy 13, trisomy 18, fragile X, Tay-Sachs disease, Hunter's syndrome and other metabolic disorders.
Answer:
The correct answer would be meiosis.
In diploid organisms, meiosis is the process that results in the formation of four haploid daughter cells from single diploid parent cell. Each of the daughter cell contains half the number of chromosomes present in parent cell.
It results in the formation of haploid gametes (sperm in males and eggs in females) which is essential in the process of sexual reproduction.
The fusion of gametes results in the formation of diploid zygote that is, maintains the diploid nature of the organism.
Hence, in absence of meiotic division the chromosomal number would keep on doubling after each generation.
In addition, crossing over (exchange of genetic material between non-sister chromatids) also takes in the prophase-I of meiosis I. It increases the genetic variation within organisms of the species. It may add survival adaptations to the population.
D. living things in the biosphere.
The atmosphere contains all the air that plants and animals both use to survive so if there was a change within it, it would affect all living creatures in the biosphere.
Pure breeding means the same as selective breeding since you take two animals and combine their traits for certain reasons
