<span>Light rays passing through glass is a process called radiation. This is a term used in physics meaning the transmission or emission of energy via particles or waves through a medium or through space. In this scenario the light rays are the energy traveling through the glass, a medium.</span>
During telophase II, the fourth step of meiosis II, the chromosomes reach opposite poles, cytokinesis occurs, the two cells produced by meiosis I divide to form four haploid daughter cells, and nuclear envelopes (white in the diagram at right) form.
Answer:
Cytotoxic T cells
Explanation:
Perforin is the cytosolic protein and upon degranulation forms pores in the target cell. Perforin protein helps in the transport of water and ions.
Perforin is present in the granules of cytotoxic T cells. These cells have the ability to kill virus infected cells and cancer cells. Cytotoxic T cells bind with the class 1 MHC molecules. These cells are also known as CD8+ T cells.
Thus, the correct answer is option (A).
Answer:
DNA contains the sugar deoxyribose, while RNA contains the sugar ribose. ... DNA is a double-stranded molecule, while RNA is a single-stranded molecule. DNA is stable under alkaline conditions, while RNA is not stable. DNA and RNA perform different functions in humans
Answer:
The correct answer in discriminating between a viable and non-viable early intrauterine pregnancy is B: "<em>Mean gestational sac diameter of > 25 mm and no embryo".</em>
Explanation:
There are <u><em>different criteria</em></u> used to discriminate between a viable and a non-viable early intrauterine pregnancy. The most often used to diagnose pregnancy failure are:
- <em>Crown-rump length criterion</em>: This is the absence of cardiac activity by the time the embryo has reached crown-rump length. <em>A crown-rump length of </em><u><em>7 mm or more</em></u><em> with no cardiac activity</em><em> has been suggested</em> by the latest studies <em>to diagnose a non-viable pregnancy</em>. There is a substantial likelihood that <em>a crown-rump length</em><u><em> </em></u><u><em>< 7 mm</em></u> can result in a <em>false-positive diagnosis of pregnancy failure.</em>
- <em>Mean sac diameter criterion</em>: This is the absence of embryo by the time the gestational sac has grown to a certain size. The gestational sac increases as the pregnancy progress. It has been suggested by the latest studies to use a <em>mean sac diameter of </em><u><em>25 mm or more</em></u><em>, and no visible embryo</em> to diagnose failed pregnancy. A mean sac diameter of <u>16 to 24 mm</u> and <u>no embryo</u> <u>is </u><em><u>suspicious</u></em> for failed pregnancy, but shouldn’t be used to diagnose it.
- <em>Time-based criteria</em>: This is the absence of an embryo by a certain point in time. If an initial sonogram shows that there is a <em>gestational sac and a yolk sac, but about </em><u><em>11 days later</em></u><em> there isn’t any embryo with cardiac activity</em>, then a <em><u>failed pregnancy</u></em> can be established. The <em><u>timing event</u></em> in early pregnancy is precise and reproducible to perform a correct diagnosis.
There are also <em>suspicious findings</em> that may help to identify a non-viable pregnancy. These are<u><em> not certain</em></u> and have not been extensively studied yet, so they <em><u>cannot be used to reliably diagnose</u></em> a pregnancy failure. A few of these findings are an empty amnion, a small gestational sac size, and the yolk sac size.
- <em>Yolk sac</em>: An e<em>nlarged yolk sac</em> sized <em>over 7 mm</em> is <em><u>suspicious</u></em> for a failed pregnancy.