Answer:
Pili
Explanation:
The sex of bacteria is determined by a structure called Pilli. Pilli is not present in all species of bacteria, but within species that have this structure, such as Escherichia coli, pilli is considered an appendage present in male bacteria.
Pilli presents itself as a long hair and can also be called F factor or fertility factor and has a reproductive function, as it allows the conjunction between two bacteria (one with pili and the other without), where the male bacteria transmit genetic resources to within the body of the female bacteria , which will combine these resources with its own resources and will give rise to another bacteria.
Answer:
When a single amino acid is encoded by more than one codon.
Explanation:
Degeneracy is when a single amino acid is encoded by more than one codon. This pehonomenon was first described by Lagerkvist where there are more codons than amino acids that could be encoded.
The best and most correct answer among the choices provided by your question is the fourth choice or letter D. Reptiles are the most critically endangered animal group. Their population is threatened due to illegal activities done by man like poaching.
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Answer:
Both cones and rods participate in dark adaptation, slowly increasing their sensitivity to light in a dim environment. Cones adapt faster, so the first few minutes of adaptation reflect cone-mediated vision.
1. Interphase is an important and the longest phase of the cell cycle during which the cell prepares for division by coping its DNA. It is metabolic phase of the cell, in which the cell grows, obtains nutrients and metabolizes them. There are three stages of interphase: G1 (the cell growth), S (replication of DNA, chromosomes are copied) and G2 (preparation for division). Without this phase, genetic material wouldn’t be ready for the process of meiosis and haploid gametes couldn’t be created.
2. Homologous chromosomes are the similar but not totally identical chromosome pairs that an organism receives from its two parents. During the prophase I of meiosis they pair up: each chromosome aligns with its homologue partner via link-chiasmata ( the two match up at corresponding positions). Those homologue pairs separate during a first stage of cell division (meiosis I-reduction of chromosomes number, from diploid to haploid), while sister chromatids separate during a second stage (meiosis II).
3. Crossing over is a process in which homologous chromosomes trade their parts. Crossing over is process of genetic recombination where DNA is cut and then repaired. Cut and repair of homologous chromosomes allow them to exchange some of their genetic information. As a consequence of crossing over, new arrangement of maternal and paternal alleles on the same chromosome is achieved. It is the way to create varations.
4. During the metaphase I, homologue pairs are lined up comparing to metaphase II where individual chromosomes are lined up. It is because during the meiosis I homologue pairs separate and chromosome number reduce from diploid to haploid. On the other hand, during the meiosis II, sister chromatids separate.
5. Nondisjunction is the consequence of cell division, where there is no properly separation. There are different forms of nondisjunction:
• failure of a pair of homologous chromosomes to separate in meiosis I,
• failure of sister chromatids to separate during meiosis II.
After nondisjunction, resulting daughter cells are with abnormal chromosome numbers -aneuploidy.
