First, you introduce to the parents the importance of karyotype test, by describing its ability to detect two broad categories of abnormalities in chromosomes, (1) and (2). You provide a few examples of genetic disorders that can be caused by chromosomal abnormalities, such as (3) and (4). Some parents would like to know what is the main cause of these genetic disorders. Without going into too much detail, you explain to them that chromosomal abnormalities are usually caused by (5) in meiosis I and meiosis II, when the homologous chromosomes or sister chromatids fail to separate during meiotic cell division.

Abnormalities in Chromosomes

1. Numerical

2. Structural

3. Down Syndrome

4. Turner Syndrome

5. Disorder or Error

Explanation:

Numerical chromosome abnormalities occur due to extra or missing chromosomes.  Structural chromosome abnormalities occur due to the irregular formation or rearrangement of the chromosomal DNA, normally called translocation.  Down syndrome occurs with extra chromosomes, more than 46. Turnover syndrome results from partial or missing X chromosomes, less than 46.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.