Answer:
Failure of chromosome to separate
Explanation:
The main essence of meiotic division is to form daughter cells with a reduced number of chromosomes that will maintain the correct chromosomal number in an organism. This is achieved when chromosomes separate during gamete formation (meiosis) to produce haploid (n) gametes.
However, a case may arise whereby chromosomes fail to separate during the anaphase stage of meiosis. This case is referred to as MEIOTIC NON-DISJUNCTION. As meiosis occurs in two stages i.e. meiosis I and II, so does meiotic nondisjunction. It can occur in meiosis I, where homologous chromosomes fail to separate or meiosis II, where sister chromatids fail to separate.
If it occurs in meiosis I, Two gametes will have a n-1 chromosome number i.e. one chromosome is missing while Two other gametes will have n+1 chromosome number i.e. one extra chromosome is added.
If it occurs in meiosis II, two normal haploid gametes (n) will be produced while the other two will have a n+1 and n-1 chromosome number respectively.
When these abnormal gametes (n+1, n-1) fuses with a normal gamete (n), the resulting organisms possess a chromosomal anomaly called ANEUPLOIDY i.e. a disorder in chromosomal number. The organisms will have 47 and 45 chromosomes depending on whether n+1 or n-1 gametes is involved respectively.
Your elbow is a hinge joint (think like a hinge on a door) and your shoulder is a ball and socket joint. Your elbow can only move two directions, but your shoulders can move anyway they want (omni-directional). Hope this helped!
C. The shape of a protein allows it to perform several different jobs.
Answer:
B. Electrophoresis separates molecules based on charge differences, thereby making it possible to separate molecules that are similar in size, shape, and density.
Explanation:
Chromatography is a process that is used for the separation of complex mixtures of molecules by many repeated partitioning between a flowing (mobile) phase and a stationary phase. The process exploits the properties of the molecules such as charge, size, binding affinity, etc.
However, gel electrophoresis is the technique that separates the molecules based on their charge or mass. It can separate a mixture of molecules with a similar charge based on their mass. Likewise, if all the molecules of a mixture have the same mass but differ in charge, gel electrophoresis can be used to separate them based on their different charges.
For example, a mixture of proteins is allowed to run through the gel of cross-linked polymer polyacrylamide under electrical potential towards the positive or negative electrode. The polyacrylamide gel serves as a sieve and allows the proteins to migrate in proportion to the charge to mass ratio. If all the proteins are of the same mass, gel electrophoresis would separate them based on their charge.
