Trisomy 21 look like in a karyotype as B. extra chromosome 21
In the first part of the twentieth century, there was much speculation of the cause of Down syndrome. In 1959 Jerome Lejeune and Patricia Jacobs, who working independently, first determined the cause to be trisomy (triplication) of the 21st chromosome. Down syndrome (DS / DNS), also known as trisomy 21 is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. Trisomy 21 is the most frequent viable chromosome disease. In Down syndrome, 95% of all cases are caused by the condition in which one cell has two 21st chromosomes instead of one, so the resulting fertilized egg has three 21st chromosomes. Hence it named as the scientific name trisomy 21.
Three to four percent of all cases of trisomy 21 are due to Robertsonian Translocation in which two breaks occur in separate chromosomes, usually the 14th and 21st chromosomes. There is rearrangement of the genetic material so that some of the 14th chromosome is replaced by extra 21st chromosome. Picture below showed the the karyotype of a male with trisomy 21.
Grade: 9
Subject: Biology
Chapter: Karyotypes
Keywords: Karyotypes
Exploding
Freezing
Burning
The answer is A for edgenutiy
C. DNA translation is producing messenger RNA.
D. DNA translation is producing ribosomal RNA.
DNA transcription is making is producing messenger RNA. Therefore, option "A" is correct. The procedure by which a cell copies a piece of DNA into RNA. The genetic information a cell needs to make proteins is carried by this copy of RNA, which is called messenger RNA (mRNA).
It moves information from the DNA in the cell's nucleus to the cytoplasm, where proteins are made, via this pathway. DNA transcription can be broken down into three main stages: initiation, elongation, and termination. These means are likewise engaged with DNA replication.
Learn more about transcription, here:
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Minerals must have a definite chemical composition which may differ within specified limits. According to geologists minerals must be:
>naturally occurring-meaning, people did not make it.
Answer: Minerals must be homogenous.
TrueFalse
During exhalation, your respiratory muscles contract to push air out of your lungs.
Your respiratory muscles contract each time you exhale.
When you exhale, the primary muscle responsible for this action is the diaphragm, which contracts and moves upwards, reducing the volume of the lungs and forcing air out. Additionally, the intercostal muscles, located between the ribs, also contract and help in the process of exhalation.
In summary, your respiratory muscles contract during exhalation to push air out of your lungs.
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