Answer:
Mule is produced from a hybrid cross.
Explanation:
A mule is the offspring which is produced by crossing or mating of male donkey with female horse.
Where the male donkey is called Jack and female horse is called mare.
The offspring produced as a result is Mule.
The gender of Mules may be male or female but consists of 63 chromosomes.
But such produced Mules are sterile.
False it affects everyone and anything. Global warming for example my friend :/
Answer:
Nervous stimulus action for muscle contraction
Explanation:
Nerve stimulation is sent to the sarcolemma, which are motor nerves at the neuromuscular junction (junction between the terminal part of a motor axon with a motor plate), after which nerve endings implant in the sarcolemma and form plaque on the surface of muscle fibers, which in turn transmit stimulus to the musculature.
Then, an electrical current (from the stimuli) is generated, it propagates through the muscle cell membrane, reaches the cytoplasm and triggers the muscle contraction mechanism.
<u>Answer:</u>
During Meiosis I the cell transform from diploid cell to haploid and ends after Telephase I.
<u>Explanation:</u>
The one and only purpose of Meiosis is to produce gametes-sex cells or sperm and eggs in the human body. The objective is to make daughter cells with precisely half the same number of chromosomes as the starting cell. In humans, meiosis is a cycle of division that .allows cell transformation from a diploid cell (one with two sets of chromosomes) to haploid cells (one with one set of chromosomes).
Their is a two-step division cycle in meiosis. During the first round of cell division, homologue pairs divide, called meiosis I. During a second round, sister chromatids split, called meiosis II. As the cell division during meiosis occurs twice, one starting cell can produce four gametes (eggs or sperm). Cells pass through 4 stages in each round of division like prophase, metaphase, anaphase, and telophase. The cycle can be understood as follows:
<u>Meiosis I: </u> Before entering meiosis I, a cell must under go an interphase. The meiosis-I involve prophase-I , metaphase-I , anaphase-I and telophase-I. The starting cell is diploid (2n=4)
- during prophase-I homologous chromosomes pair-up and exchange fragments called as "crossing over".
- during metaphase-I homologue pairs line up at the metaphase plate.
- during anaphase-I homologues separate to opposite ends of the cells and then sister chromatids stay together.
- during telophase-I the chromosomes reach at opposite poles of the cell and result each chromosome has two sister chromatides, non identical in nature.
- Finally the newly forming cells are "haploid" i.e n=2.
