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:
muscular
Explanation:
Skeletal muscles are attached to bones through the tendons. Tendons are inelastic connective tissue fibres. Muscles that bring about movement at a joint are in pairs of antagonist muscles. A muscle is attached at two points, the origin and insertion where it affects the movement across a joint. Movement is caused by the contraction of a muscle which exerts considerable force.
stem cutting
► planting a portion of an immature cane's stem as a seed into the roots.
Answer:
Breathing is the process of exchange of carbon dioxide and oxygen between the body and the environment. The exchange of gases depends upon the partial pressure of oxygen.
When the individual hold its breath, the amount of oxygen level in the body gets decreased. This increases the carbon dioxide level in the body. The increase in the carbon dioxide level reduces pH and increase the hydrogen ions in the body. The biocarbonate levels in the body also increases.
Explanation:
5 factors are:
1). habitat change, 4 native species, (can not survive or reproduce 2 repopulate the area).
2).physical modifications of h20, or rivers.( dam's, rivers, changing h2o flow. critical 4 native fish, water fowl, microbes that eat harmful bacteria.
3).species that are not born 2 the area
4). pollution, due 2 human modification..
5). climate change, because of human modification..
hope this helps..
