¶2Appellant, Edward Moore, was convicted by a jury of involuntary manslaughter and was sentenced to a term of two and one-half to five years imprisonment. Appellant filed a direct appeal. Counsel failed to file a brief and the appeal was dismissed. Thereafter, appellant filed a petition under the Post Conviction Relief Act, 42 Pa.C.S. § 9541 et seq., and his appellate rights were reinstated nunc pro tunc. This direct appeal followed. We affirm.
¶3On appeal, appellant claims that trial counsel was ineffective for: (1) failing to preserve his claim that the evidence is insufficient to sustain his conviction; (2) failing to preserve his claim that the verdict of guilt is against the weight of the evidence; (3) failing to object to the prejudicial remarks made by the Assistant District Attorney during his summation to the jury; and (4) failing to request that the jury be instructed regarding appellant’s failure to testify at trial.
¶4On November 28, 1991, Dennis Williams, the decedent, exited Smith’s Bar in Philadelphia. Appellant approached the decedent, struck him from behind, and the decedent fell to the ground. The decedent tried to get up, but appellant kicked him in the face. The decedent fell back again, hitting his head on the concrete sidewalk. The decedent died as a result of these injuries.
¶5In general, trial counsel is presumed to be effective and appellant has the burden of proving otherwise. Commonwealth v. Williams, 524 Pa. 218, 570 A.2d 75 (1990). In reviewing ineffectiveness claims, we must first determine whether the issue underlying the charge of ineffectiveness is of arguable merit. Commonwealth v. Sherard, 483 Pa. 183, 394 A.2d 971 (1978). If not, we need look no further since counsel will not be deemed ineffective for failing to pursue a meritless issue. Commonwealth v. Lennox, 250 Pa.Super. 80, 378 A.2d 462 (1977). If there is arguable merit to the claim, we will then look to see whether the course chosen by counsel had some reasonable basis aimed at promoting his client’s interests. Commonwealth v. Evans, 489 Pa. 85, 413 A.2d 1025*501(1980). Further, there must be a showing that counsel’s ineffectiveness prejudiced appellant’s case. Commonwealth v. Pierce, 515 Pa. 153, 527 A.2d 973 (1987).
¶6Appellant first claims that the evidence is insufficient to support his conviction. He contends that trial counsel was ineffective for failing to preserve this issue for appellate review.
¶7In reviewing a sufficiency of the evidence claim, we view the evidence, together with all reasonable inferences therefrom, in the light most favorable to the Commonwealth. Commonwealth v. Rose, 463 Pa. 264, 344 A.2d 824 (1975). A mere conflict in the testimony does not render the evidence insufficient, Commonwealth v. Verdekal, 351 Pa.Super. 412, 506 A.2d 415 (1986), because it is within the province of the fact finder to determine the weight to be given to the testimony and to believe all, part, or none of the evidence. Commonwealth v. Whitfield, 475 Pa. 297, 380 A.2d 362 (1977).
¶8Involuntary manslaughter is defined as follows:
(a) General rule. — A person is guilty of involuntary manslaughter when as a direct result of the doing of an unlawful act in a reckless or grossly negligent manner, or the doing of a lawful act in a reckless or grossly negligent manner, he causes the death of another person.
¶918 Pa.C.S. § 2504(a).
¶10Thus, the crucial element necessary for a finding of involuntary manslaughter is conduct that is reckless or grossly negligent. Commonwealth v. Stehley, 350 Pa.Super. 311, 504 A.2d 854 (1986).
¶11Viewing the evidence in a light most favorable to the Commonwealth, there is sufficient evidence to sustain appellant’s conviction. Appellant approached the decedent from behind and struck him, causing him to fall to the ground. As the decedent tried to get up, appellant kicked him in the face causing him to fall back again with his head striking the concrete sidewalk. This evidence is sufficient to sustain appellant’s conviction. See, Commonwealth v. Stehley, 504 A.2d at *502860, 504 A.2d 854 (Grabbing, pushing or shoving a 62-year-old man over a porch railing so that he hits the ground four feet below head first, is sufficient to support a finding of recklessness or gross negligence).
¶12At trial, defense witness, Leroy Lawton, stated that the decedent pushed appellant and took a swing at him. Appellant punched the decedent once and he fell back hitting his head on the sidewalk.
¶13On appeal, appellant argues that the Commonwealth failed to disprove self-defense beyond a reasonable doubt. This claim necessarily requires a finding that appellant’s version of the events in question is more credible than the testimony presented by the Commonwealth at trial. Commonwealth v. Gonzales, 415 Pa.Super. 564, 609 A.2d 1368 (1992). However, the credibility of the self-defense testimony was for the jury which could believe all, some or none of it. Commonwealth v. Ignatavich, 333 Pa.Super. 617, 482 A.2d 1044 (1984); Commonwealth v. London, 461 Pa. 566, 337 A.2d 549 (1975). The jury was properly instructed on the elements of self-defense and the Commonwealth’s burden of proof. We will not disturb the jury’s determination in this regard. Id.Because this claim is meritless, trial counsel was not ineffective for failing to preserve it. Commonwealth v. Cook, 383 Pa.Super. 615, 557 A.2d 421 (1989).
¶14Appellant next claims that the verdict of guilt is against the weight of the evidence. He again contends that trial counsel was ineffective for failing to preserve this issue for appellate review.
¶15When reviewing a weight of the evidence claim, we look at all of the evidence. Commonwealth v. Sullivan, 372 Pa.Super. 88, 538 A.2d 1363 (1988). In reviewing such a claim, a new trial will not be warranted unless the verdict was so contrary to the evidence as to shock one’s sense of justice. Id.Only in this situation is the award of a new trial imperative, so that right may be given an opportunity to prevail. Id.; Commonwealth v. Taylor, 324 Pa.Super. 420, 471 A.2d 1228 (1984); Commonwealth v. Gonce, 320 Pa.Super. 19, 466 A.2d *5031039 (1983). However, it is not the function of this court to substitute its judgment for that of the jury on the issues of credibility and weight of the evidence. The weight to be accorded conflicting evidence is exclusively for the fact finder and such determinations will not be disturbed if they are supported by the record. Commonwealth v. Hamilton, 376 Pa.Super. 404, 546 A.2d 90 (1988). Only if the evidence is so unreliable or contradictory as to make any verdict based thereon pure conjecture is appellant entitled to a new trial on this basis. Commonwealth v. Maute, 336 Pa.Super. 394, 485 A.2d 1138 (1984).
¶16Appellant contends the verdicts are against the weight of the evidence because of inconsistencies between the evidence presented at trial by the defense and the Commonwealth. Appellant argues that the evidence presented by the defense relating to the facts surrounding the killing was more credible than that presented by the Commonwealth. We are unable to find that the inconsistencies pointed out by appellant create such contradictions as to make the verdicts mere surmise or conjecture. Commonwealth v. Maute, supra.Where evidence is conflicting, the credibility of witnesses is for the fact finder and we will not disturb this determination on appeal. Commonwealth v. Hamilton, supra.Because this claim is meritless, trial counsel was not ineffective for failing to preserve it. Commonwealth v. Cook, supra.
¶17Appellant next claims that trial counsel was ineffective for failing to object to the prejudicial remarks made by the Assistant District Attorney during his summation to the jury. Every objectionable remark does not automatically result in a new trial. Commonwealth v. Jones, 391 Pa.Super. 292, 570 A.2d 1338 (1990). In order to constitute reversible error, the unavoidable effect of the prosecutor’s comments must be to prejudice the jury in such a way that a fixed bias and hostility exist toward the defendant, and therefore the jury is not capable of weighing the evidence and rendering a true verdict. Commonwealth v. Simon, 432 Pa. 386, 248 A.2d *504289 (1968); Commonwealth v. Brawner, 381 Pa.Super. 265, 553 A.2d 458 (1989).
¶18Presently, the complete quote is as follows:
¶19“People talk alot about the system, the system — what is the system; the system does not work; the system does not protect the little man; the system does everything to protect the guilty.
¶20Well today the system is you. Mr. Dennis is a little man. I would ask you to make the system work for him.
¶21When you walked in here a couple days ago and took a look at Edward Moore, you may have looked at him and said, I wonder what he did. Well, you have heard the evidence. You know what he did. The only question left is what are you going to do about it.”
¶22Tr. 6/12/92, pp. 336-337.
¶23We have reviewed the prosecutor’s entire closing statement and are unable to find that the unavoidable effect prejudiced the jury or caused a fixed bias or hostility towards appellant. Commonwealth v. D'Amato, 514 Pa. 471, 526 A.2d 300 (1987). When taken in the proper context and after review of all the evidence, we cannot hold that the prosecutor’s remarks were unfair or prejudicial. Commonwealth v. Johnson, 527 Pa. 118, 588 A.2d 1303 (1991); Commonwealth v. Ferrari, 406 Pa.Super. 12, 593 A.2d 846 (1991). It is clear that the prosecutor was summarizing the evidence and the role of the jury in the proceedings with the oratorical flair permitted during argument. Commonwealth v. Chester, 526 Pa. 578, 587 A.2d 1367 (1991); Commonwealth v. Hamm, 325 Pa.Super. 401, 473 A.2d 128 (1984). Trial counsel is not ineffective for failing to assert meritless claims. Commonwealth v. Smith, 490 Pa. 380, 416 A.2d 986 (1980).
¶24Finally, appellant claims that trial counsel was ineffective for failing to request that the jury be instructed that no inference of guilt could be drawn from his failure to testify at trial. Under the Fifth Amendment to the United States Constitution and Article 1, Section 9 of the Pennsylvania Constitution, a criminal defendant is entitled to receive a *505specific “no adverse inference” jury instruction when a timely request is made to the trial court. Commonwealth v. Lewis, 528 Pa. 440, 598 A.2d 975 (1991); Commonwealth v. Howard, -Pa.-, 645 A.2d 1300 (1994). The explicit “no adverse inference” instruction may not be replaced by general preliminary instructions informing the jury that the defendant has no duty to testify. Id.
¶25In the instant case, it is clear that appellant was entitled to have the jury receive a “no adverse inference” instruction. Although the jury was told that appellant had no obligation to testify in the preliminary instructions, trial counsel never requested that the jury receive a “no adverse inference” instruction before retiring to deliberate. Therefore, we find that there is arguable merit to appellant’s claim regarding trial counsel’s ineffective assistance. Id.However, even if we assume that counsel had no reasonable basis for failing to request this instruction, appellant is precluded from obtaining relief because he has failed to state how he was prejudiced by counsel’s omission. Id.; Commonwealth v. Pierce, supra.As a result, this claim of ineffective assistance must fail as well. Commonwealth v. Howard, supra.
¶26Judgment of sentence affirmed.