Answer:
transcription initiation
Explanation:
Transcription is a process by which genetic information from DNA is used to synthesize an RNA molecule, usually, a messenger RNA (mRNA), which is subsequently utilized to synthesize a protein by a process called translation. Transcription in prokaryotes has three steps:
1-Initiation: the RNA polymerase is a multisubunit enzyme (holoenzyme) composed of two α, one β, one β’ and one ω and σ subunits (α2ββ’ωσ). This holoenzyme binds to the promoter region of the template DNA strand.
2-Elongation. The sigma σ factor of the holoenzyme is released and the complex and the core enzyme (α2 ββω) moves along the template strand, thereby producing an mRNA sequence
3-Termination. This step can be Rho-dependent, where a protein named "Rho" recognizes the termination site and stop transcription, and Rho-independent (transcription continues until the termination sequence is reached).
In consequence, Rifamycin is likely to block the initiation of transcription because the core RNA enzyme needs to bind the sigma factor (σ) for initiation of transcription in bacteria.
Answer:
Protein benefit animals because they need this to form new skin cells. They also use protein to grow hair, build muscle tissue etc. Protein also helps the animals to create chemicals like hormones and enzymes that are needed for their normal function.
Explanation:
A macrophage may engulf a pathogen by endocytosis, which involves the reorganization of actin microfilaments in the membrane and microtubules in the cytoskeleton.
<h3>What is endocytosis?</h3>
Endocytosis is a cellular process by which a cell can absorb materials from the surrounding medium, such as viruses and bacteria in the case of macrophages.
Microfilaments and microtubules are proteins that form part of the cytoskeleton and dynamic conformational changes of them are associated with the cytoskeletal rearregement during the phagocytic process.
The actin microfilaments in the membrane and microtubules in the cytoskeleton form part of the process of endocytosis because they need to reorganize during cell movement.
In conclusion, a macrophage may engulf a pathogen by endocytosis, which involves the reorganization of actin microfilaments in the membrane and microtubules in the cytoskeleton.
Learn more about actin filaments here:
brainly.com/question/13777481
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Answer:
1 . The stage on the first meiotic division when the homologous chromosomes move to opposite poles but the sister chromatids remain together
: b. Anaphase I
2 . The stage in the second meiotic division where sister chromatids migrate to opposite poles
: c. Anaphase II
3 . A structure on the chromosome that holds a pair of chromatids together during replication
: f. centromere
4 . A double-stranded chromosome following replication attached by a centromere
: d. chromatid
5 . A condition where non-sister chromatid of homologous chromosomes exchange genes
: e. crossing over
6 . The stage in the first meiotic division where the homologous chromosomes line up as a pair
: a. Metaphase I
7 . The stage in the second meiotic division where the chromatid pair lines up at the equator of the cell: g. Metaphase II
Explanation:
DNA replication occurs during the S phase of the interphase of the cell cycle. The replicated DNA molecules are accommodated in two sister chromatids of a chromosome that are held together by a centromere.
During prophase I, the chromatids of a homologous chromosome pair exchange a genetic segment. This process is called crossing over. It generates recombinant chromatids with new combinations of genes.
Metaphase I of meiosis I includes the alignment of homologous pairs of chromosomes at the cell's equator. This is followed by separation and movement of homologous chromosomes to the opposite poles of the cell during anaphase I.
Metaphase II of meiosis II includes the alignment of individual chromosomes, each with two sister chromatids, on the cell's equator. During anaphase II, splitting centromere separates the sister chromatids which then move to the opposite poles of the cell.
A convergent boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other causing a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Benioff Zone.
