单项选择题
TIRAP is an adapter molecule associated with toll-like receptors (TLRs) of the immune system, which identify pathogen-associated molecular patterns. This protein is involved in the TLR4 intracellular signaling pathway. It activates NFkB, MAPK1, MAPK3 and JNK, which then result in cytokine secretion and the inflammatory response. 附件tirap.fasta是人Homo sapiens、猕猴Macaca fascicularis、大象Loxodonta africana、马Equus caballus、鸡Gallus gallus、袋獾Sarcophilus harrisii、爪蟾Xenopus tropicalis、河豚Takifugu rubripes、剑尾鱼Xiphophorus maculatus、斑马鱼Danio rerio十个物种的TIRAP蛋白质序列。请用MEGA7为这些序列构建一株NJ树。MEGA7用ClustalW方法做出的多序列比对结果截图（1分）。参数设置页面截图：步长检验（BOOTSTRAP）取值100，其他参数默认（1分）。构建出来的Original Tree截图（1分）。构建出来的Bootstrap consensus tree截图（1分）。说出Original Tree和Bootstrap consensus tree树枝的长短有什么区别（1分）。
A.fasta是人Homo
