Having a controlled group is very important.
Reason: If scientists did not have a controlled group then, they would have data for the test but they might know if the results changed or not. Scientists need a controlled group because the controlled group is like the original. They need the original group to help them know what improved or did not improve.
For example, if you were testing whether or not different types of music helps with studying, then you will need a group that does not listen to music so you can know if different types of music actually improve or just make studying worse.
Having a controlled group helps you know the difference between observations in a easier way. The controlled group is not something people should ignore. It might seem useless at first but, when a person starts to finish up their project or test then, they will understand why a controlled group is important. By the time they do, it might be too late so make sure you people use a controlled group(Especially in the Science Projects).
(Hope this helps : ) )
Answer:
a. The spindle apparatus is present in cells undergoing <u>mitosis and meiosis. </u><u> </u>the spindle is crucial for chromosome sorting.
b. Chromosome replication occurs just prior to <u>mitosis and meiosis I. </u> DNA needs to be copied during S fase to have enough DNA and transfer it to the daughter cells.
c. The cells resulting from <u>mitosis </u>in a haploid cell have a ploidy of n.
Mitosis produces identical cells.
d. The cells resulting from <u>meiosis II </u>in a diploid cell have a ploidy of n. meiosis is the only process that causes chromosome reduction (assuming no errors).
(e). Homologous chromosome pairing regularly occurs during <u>meiosis I.</u> Each daughter cell needs 1 chromosome of each kind
(f). Non-homologous chromosome pairing regularly occurs during <u>none</u>. This is kind of an error.
(g). Physical recombination leading to the production of recombinant progeny classes occurs during <u>Meiosis I </u>
(h). Centromere división occurs during meiosis II and mitosis
(i) Non-sister chromatids are found in the same cell during <u>meiosis II</u>
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Both viral vectors and bacterial plasmids can be used to transfer genes into an organism. An invitro fertilisation could maybe be helpful, but not with engineered genes, but existing genes.
A) viral vectors is the best answer is viruses can be used to infect plants and change their DNA- bacteria aren't as good, as they can mostly be used to modify other bacteria only
Answer:
The sentence that says: Blood PO2 affects respiration only indirectly, IT IS FALSE, since the partial pressure of oxygen gas together with carbon dioxide are factors that DIRECTLY affect respiration.
The sentence that says: Unselected changes in arterial pH as a result of CO2 retention or metabolic factors act through peripheral chemoreceptors. It is FALSE, since the central chemoreceptors together with the peripheral ones can detect the metabolic acidosis generated by the CO2 retention, this is how the CNS receptors capture the CO2 that crosses the blood-brain barrier and stimulates hyperventilation to compensate for this phenomenon and increase the plasma concentrations of partial oxygen pressures.
The sentence that says: in selecting When arterial PO2 falls below 60 mm Hg, it becomes the main stimulus for breathing, IT IS FALSE, since it not only encourages ventilation to promote oxygenation but also activates the renin-angiotensin-aldosterone in order to recover blood volume and thus achieve adequate blood pressure.
In addition, hypovolemia triggers tachycardia and weakening symptoms, which is why the drop in blood pressure is not the main stimulus for breathing.
Explanation:
Breathing is promoted by muscle contraction, medium and high temperatures (that is, in hot or hot climates), partial concentrations of oxygen and carbon dioxide both in the atmosphere and in our blood, and in situations of systemic imbalances such as metabolic acidosis or alkalosis.
