Dolphins are extremely sociable creatures. Massive interaction with wild dolphins can put a strain on their relationship because they might grow distant or become neglected due to human interaction.
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.
Answer:
D) Na+ is used to repolarize the membrane.
Explanation:
Option D is wrong choice because it is K+ which is used to repolarize the membrane not Na+.
As soon as membrane gets depolarized because of influx of Na+ due to opening of voltage gated Na+ channels simultaneous opening of voltage gated K+ channels and closing of Na+ voltage gated channels takes place. As a result of which K+ moves out of the cell leading to drawing of electrochemical gradient out of the cell.
In order to achieve resting membrane potential, more Na+ must be out of the cell and more K+ must be inside the cell. There are many leaky channels on neurons from which Na+ has tendency to leak into the cell while K+ has the tendency to leak outside of the cell. So Na+/K+ pump which is located on the membrane of neuron keeps pushing Na+ outside of the cell and K+ inside the cell so as to maintain resting membrane potential which is -70 mV.
Thymine, is the answer you’re looking for.
