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.
I believe the name for OH- ions is hydroxide.
Answers
1. True, trees shed their leaves during winter to survive the harsh winter.
2. True, some trees have leaves that are pointed needles to survive the cold.
Explanation
Trees lose their leaves during winter , during this period, the ground freezes making the soil to be dry as in desert, hence to reduce loss of moisture through transpiration that occurs via the leaves, the trees shed all leaves until warmer springs start. For example deciduous trees in temperate forest shed leaves every winter.
Needle like leaves can survive ice and snow during cold. Insects will not be able to feed on such leaves because of their toughness. In addition to that, needle shaped leaves have lower wind resistance thus can not easily make a tree fall over during big storms.
For the answer to the question above, I think the answer to this question is to <span>warn your family that fecal coliform bacteria is an indication of harmful microorganisms in the water</span>.
This may cause you or your family some serious health problems.
