Answer:
The correct answer is option C. "2+".
Explanation:
A common procedure to test for the presence of antigens is to perform an agglutination reaction by performing an antibody screen. In an agglutination reaction that is graded 2+ the red blood cells start to be broken and medium-sized agglutinates are formed. In this reaction no red blood cells are free, only agglutinates are seen at the bottom of the microtubes. The characteristics of the reaction herein described concur with an agglutination reaction that is graded 2+.
<span>An important prelude to a greeting or opening line is often eye contact.</span>
Complete question:
Prophase of meiosis I has some important differences from prophase of mitosis. These differences include: ___________BLANK pair, and _________BLANK occurs.
A: chromatids; condensation
B.,chromosomes; separation
C. homologous chromosomes; crossing over
D. homologous chromatids; separation
Answer:
C. homologous chromosomes; crossing over
Explanation:
Prophase I of meiosis and prophase of mitosis are quite distinct with respect to the events occurring in the cells. Prophase-I of meiosis is a relatively long stage. The Zygotene stage of prophase-I includes the pairing of homologous chromosomes. This pairing is mediated by synaptonemal complex and the process is called synapsis. The paired chromosomes undergo the process of crossing over during the pachytene stage of prophase-I. In crossing over, the non-sister chromatids of the bivalents exchange some genetic material between them. The events of synapsis and crossing over do not occur during prophase of mitosis.
Answer:
C
Explanation:
If the population is in equilibrium, the allele frequencies will be constant.
There is nothing about the heritability of dominant or recessive alleles that make dominant ones any more likely by nature. This rules out choices A and B.
Genetic drift mentioned in D refers to alleles leaving a population. Nothing like this was mentioned in the question, so count that answer out.
C is the only remaining answer by process of elimination. It is also the most logical choice. Directional selection refers to a process of natural selection wherein extreme phenotypes (notched leaves, or non-notched leaves) are favored. In this case, there may be some external pressure causing notched leaf plants to be more evolutionarily fit, meaning that they survive long enough to reproduce more and increase allele frequency of the dominant allele.
As temperature increases, the rate of transpiration rises as there is more evaporation.
As precipitation in the atmosphere rises, the rate of transpiration falls. Since precipitation means there is more water in the atmosphere as compared to inside the plant, less water is lost through osmosis.
