Cyclic phosphorylation is a kind of phosphorylation in which ATP is formed from an ADP when phosphate group is attached to it during light reaction of photosynthesis.
Answer:
The correct answer is option c. "frameshift mutations".
Explanation:
The reading frame of a gene is based on base-pair triplets, starting from the start codon until the ribosome encounters with the end codon. Base-pair additions and deletions are collectively referred to as frameshift mutations because they alter the reading frame of the gene. Base-pair additions and deletions break down the original sequence of the gene triplets, which alters the open reading frame and usually results in the production of non active proteins.
<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.
<span>Lamarck proposed that by selective use or disuse of organs, organisms acquired or lost certain traits during their lifetime. Then passed onto offspring-leading to change in species.</span>
Mechanical stress occurs in the form of weight bearing movement and exercise, and it is required for normal bone remodeling. Stress is detected by osteocytes and communicated to osteoblast. These cells then increase synthesis of esteoid, and this is followed by deposition of mineral salts. Bone strength increases over a period of time in response to mechanical stress.
