Answer:
c. inner cell mass
Explanation:
The inner cell mass of the blastocyst forms the embryo while the outer layer, the trophoblast forms the placenta.
Answer:
The a.nswer is smooth endoplasmic reticulum
Explanation:
The smooth endoplasmic reticulum is responsible for the synthesis of lipids (including phospholipids, cholesterol required for many hormones, ceramides, lipoproteins), calcium storage, and cell detoxification (in liver cells).
Answer: 15
Explanation: since it affects only 1 out of 20, you can divide 300 by 20 which equals 15
Introduction :-)
The <em>amniotic fluid</em> is the protective liquid contained by the <em>amniotic sac</em> of a <em>gravid amniote</em>. This <em>fluid</em> serves as a cushion for the growing <em>fetus</em>, but also serves to facilitate the exchange of nutrients, water, and biochemical products between <em>mother</em> and <em>fetus</em>.
Importance :-)
- <em>It helps to protect the fetus from trauma to the maternal abdomen.</em>
- <em>It cushions the umbilical cord from compression between the fetus and uterus.</em>
- <em>It has antibacterial properties that provide some protection from infection.</em>
- <em>It serves as a reservoir of fluid and nutrients for the fetus.</em>
<em></em>
Formation :-)
<em>Amniotic fluid </em>is present from the formation of the <em>gestational sac.</em> <em>Amniotic fluid </em>is in the <em>amniotic sac.</em> It is generated from <em>maternal plasma</em>, and passes through the <em>fetal membranes</em> by <em>osmotic</em> and <em>hydrostatic forces</em>. When <em>fetal kidneys</em> begin to function around week 16, <em>fetal urine</em> also contributes to the <em>fluid.</em> In earlier times, it was believed that the <em>amniotic fluid</em> was composed entirely of <em>fetal urine</em>.
The <em>fluid</em> is absorbed through the <em>fetal tissue</em> and <em>skin</em>. After <em>22 to 25 week </em>of<em> pregnancy</em>, <em>fraternization</em> of an <em>embryo's skin</em> occurs. When this process completes around the <em>25th week</em>, the<em> fluid</em> is primarily absorbed by the <em>fetal gut</em> for the remainder of <em>gestation</em>.
<em>Contents :-)</em>
At first, <em>amniotic fluid</em> is mainly water with <em>electrolytes</em>, but by about the <em>12-14th week</em> the <em>liquid</em> also contains <em>proteins, carbohydrates, lipids and phospholipids, and urea</em>, all of which <em>aid</em> in the growth of the <em>fetus</em>.
Hope its helpful :-)
If so, please mark me as brainlist :-)
Answer:
Okay
Explanation:
Human topoisomerase I plays an important role in removing positive DNA supercoils that accumulate ahead of replication forks. It also is the target for camptothecin-based anticancer drugs that act by increasing levels of topoisomerase I-mediated DNA scission. Evidence suggests that cleavage events most likely to generate permanent genomic damage are those that occur ahead of DNA tracking systems. Therefore, it is important to characterize the ability of topoisomerase I to cleave positively supercoiled DNA. Results confirm that the human enzyme maintains higher levels of cleavage with positively as opposed to negatively supercoiled substrates in the absence or presence of anticancer drugs. Enhanced drug efficacy on positively supercoiled DNA is due primarily to an increase in baseline levels of cleavage. Sites of topoisomerase I-mediated DNA cleavage do not appear to be affected by supercoil geometry. However, rates of ligation are slower with positively supercoiled substrates. Finally, intercalators enhance topoisomerase I-mediated cleavage of negatively supercoiled substrates but not positively supercoiled or linear DNA. We suggest that these compounds act by altering the perceived topological state of the double helix, making underwound DNA appear to be overwound to the enzyme, and propose that these compounds be referred to as ‘topological poisons of topoisomerase I’
