Answer the following question given this paragraph: The Promoter and the Transcription Machinery Genes are organized to make the control of gene expression easier. The promoter region is immediately upstream of the coding sequence. This region can be short (only a few nucleotides in length) or quite long (hundreds of nucleotides long). The longer the promoter, the more available space for proteins to bind. This also adds more control to the transcription process. The length of the promoter is gene-specific and can differ dramatically between genes. Consequently, the level of control of gene expression can also differ quite dramatically between genes. The purpose of the promoter is to bind transcription factors that control the initiation of transcription. Within the promoter region, just upstream of the transcriptional start site, resides the TATA box. This box is simply a repeat of thymine and adenine dinucleotides (literally, TATA repeats). RNA polymerase binds to the transcription initiation complex, allowing transcription to occur. To initiate transcription, a transcription factor (TFIID) is the first to bind to the TATA box. Binding of TFIID recruits other transcription factors, including TFIIB, TFIIE, TFIIF, and TFIIH to the TATA box. Once this complex is assembled, RNA polymerase can bind to its upstream sequence. When bound along with the transcription factors, RNA polymerase is phosphorylated. This releases part of the protein from the DNA to activate the transcription initiation complex and places RNA polymerase in the correct orientation to begin transcription; DNA-bending protein brings the enhancer, which can be quite a distance from the gene, in contact with transcription factors and mediator proteins (Figure 16.9). Q: Genes are organized to make the control of gene expression easier. the promoter region is immediately upstream of this? Choices: - propagate sequence - organic sequence - signalling sequence - coding sequence A:
coding sequence
Answer the following question given this paragraph: would not be surprised if the surviving populations experienced serious bottlenecks. The subsequent diversification of the surviving organisms, such as the Dinosauria (which includes the extinct dinosaurs and modern birds) and the Cynodontia, which includes the ancestors of modern mammals, including us, could be due in part to these bottleneck-associated effects, for example, through the removal of competing species or predators. An astreroid impact, known as the Cretaceous-Tertiary event, occurred ~65 million years ago; it contributed to the extinction of the dinosaurs and led to the diversification of mammals (which had first appeared in the fossil record ~160 million years ago). While surviving an asteroid impact (or other dramatic changes in climate) may be random, in other cases who survives a bottleneck is not. Consider the effects of a severe drought or highly virulent bacterial or viral infection; the organisms that survive may have specific phenotypes (and associated genotypes) that significantly influence their chance of survival. In such a case, the effect of the bottleneck event would produce non-random changes in the distribution of genotypes (and alleles) in the post-bottleneck population these selective effects could continue to influence the population in various ways. For example, a trait associated with pathogen resistance may also have negative phenotypic effects. After the pathogen-driven bottleneck, mutations that mitigate the resistance trait's negative effects (and may have their own effects) can be selected. The end result is that traits that would not be selected in the absence of the pathogen, are selected. In addition, the very occurrence of a rapid and extreme reduction in population size has its own effects. For example, it would be expected to increase the effects of genetic drift (see below) and could make finding a mate more difficult. We can identify extreme population reduction events, such as founder effects and bottlenecks, by looking at the variation in genotypes (that... Q: The rate of the accumulation of neutral what serves as a type of population-based biological clock? Choices: - prokaryotic - enzymes - eukaryotes - polymorphisms A:
polymorphisms
Q: Answer the following question given this paragraph: Q: What evolutionary concept characterizes a species by body shape and other structural features? Choices: - geologic species concept - spontaneous evolution theory - primary speciation - morphological species concept A:
A: morphological species concept
Question: Answer the following question given this paragraph: The lungs release carbon dioxide into the air. Carbon dioxide is a gaseous waste product of the cells. Wastes are excreted from the body by the excretory system. Therefore, the lungs are organs of the excretory system as well as the respiratory system. Q: Are the lungs organs of the excretory system, the respiratory system, or both? Choices: - excretory - respiratory - neither - both A:
Answer: both
*Question*
Answer the following question given this paragraph: Laurentbonneau. The holes in bread are created by yeast fermentation . CC-BY 3.0. Q: What causes holes in bread? Choices: - heat - alcohol fermentation - moisture - yeast fermentation A:
**Answer**
yeast fermentation
*Question*
Answer the following question given this paragraph: A compound is a substance that consists of two or more elements. A compound has a unique composition that is always the same. The smallest particle of a compound is called a molecule. Q: What is the smallest part of a compound? Choices: - electron - dna - nucleus - molecule A:
**Answer**
molecule