There should be options for this question. I manged to find them elsewhere. They are:
A) the period during which tremendous growth occurs and the organs continue to develop and become functional
B) the period during which the umbilical cord develops
C) the period during which the major organs and structures of the organism first develop
D) the period during which the zygote moves down to the uterus and begins to implant in the lining
The correct answer is C. The embryonic period is the period during which the major organs and structures of the organism first develop. The embryonic period lasts from implantation of the egg in the uterus until about 8 weeks from the time of conception. It is the second major stage of prenatal development, prior to embryonic is the germinal stage and lastly is the fetal stage.
Hello. This question is incomplete. The full question is:
"You determine that you have only 3 copies left of an important DNA fragment, so you decide to amplify it. Using flanking primers, how many PCR cycles would you have to run to generate over one billion (10^9) copies of the fragment?
"
Answer:
Approximately 29 cycles of PCR would be required.
Explanation:
As you may already know, PCR is a technique used in molecular biology that allows part of a DNA molecule to be recycled into millions of copies.
PCR allows this replication to be done through cycles. Each PCR cycle lasts about 2 minutes and allows the DNA molecule to undergo the separation of the strands, the binding of the primers and the synthesis of new DNA strands through DNA polymerase. This cycle is usually repeated 32 times, but this number may change depending on the number of copies the researcher thinks is necessary.
In this case, if a researcher wants 10 ^ 9 copies of DNA, he must do the following calculation to find the number of PCR cycles needed:
32 ^ x = 10 ^ 9
x = 28.3 = approximately 29 cycles.
Answer - B
Fish and reptiles both are ectothermic but fish have gills and reptiles have lungs. Ectothermic organisms do not have an internal mechanism of regulating their body temperature and are dependent on their atmosphere for temperature regulation. Fish, reptiles and invertebrates are examples of ectothermic organisms.
·meiosis ensures that the gametes formed are haploid from 2n to n
.ref to reduction division occurring in meiosis 2
.zygote becomes diploid due to the 2 sets of chromosomes from sperm and ovum
.can survive without the reproductive system
.reasons can be due to infection such as cancer of prostate in men or removal of uterus
.discuss the social implications that occur with the procedure that is in contrast with religion
Hello there,
The answer to your question is <span>mast
Hope this helps :))
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