Answer: e. 2.5 ml
Explanation:
According to the dilution law,
where,
= concentration of stock solution = 20X
= volume of stock solution = ?
= concentration of required solution= 1X
= volume of required solution= 50 ml
Thus 2.5 ml much of a 20X tricaine stock solution is needed to dilute in order to make your solution.
Answer:
Restoration of the diploid condition and the determination of gender.
Explanation
Conception occurs when the male gamete fertilizes the egg and an embryo is formed.
This is event significance in biological developmental science because at this point is when the diploid condition is restored.
When the sperm containing half the number of chromosomes of the father fuses with the egg that contains half the number of chromosomes from the mother to form a diploid embryo.
Secondly, depending on the sperm that fertilized the egg, gender is determined.
Answer:
Non-coding DNA regions play important roles in regulating transcriptional activity by encoding different types of non-coding RNAs (ncRNAs), acting as scaffold attachment regions, acting as enhancer specific regions, etc.
Explanation:
Historically, it had been believed that non-coding DNA sequences were 'junk DNA' since they don't encode for proteins (beyond the sequences that are transcribed into functional non-coding RNAs, i.e., transfer RNA and ribosomal RNA). However, in the last years, it has been shown that non-coding DNA sequences play critical roles in regulating gene expression and genome function. For example, evolutionary conserved non-coding RNAs (ncRNAs) with regulatory roles on gene expression such as, for example, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been mapped in non-coding DNA sequences, thereby evidencing the functional significance of these regions. In consequence, the conservative nature of certain non-coding DNA sequences evidence that mutations in such regions may have significant deleterious effects, and thereby they could have a negative impact on the fitness of the individual.
Answer:
Explanation:
In 1869, Friedrich Miescher isolated "nuclein," DNA with associated proteins, from cell nuclei. He was the first to identify DNA as a distinct molecule. Phoebus Levene was an organic chemist in the early 1900's. He is perhaps best known for his incorrect tetranucleotide hypothesis of DNA.
