Answer:
Molecules which move against the concentration gradient across the cell membrane employ the mechanism of active transportation.
Explanation:
Normally, permitted molecules moves across the cell membrane of the cell by the process of diffusion and osmosis. This is used when molecules move from hypertonic region to hypotonic region (if ions) and hypotonic to hypertonic (if water). This is a passive transportation which do not require the expense of energy from the cell.
In contrast, when molecules move in or out of the cell against their concentration gradient, that is ions moving from hypotonic region to hypertonic region, they implore the expense of energy in form of adenosine triphosphate (ATP), and the involvement of the membrane carrier proteins. This is called active transport.
Explanation:
Genetic variation in offspring during sexual reproduction is caused by
- crossing over
- independent assortment
- randomized fertilization
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. To produce daughter cells during cell division, the chromosomes (total number of chromosomes (2n)) are copied before the cell splits into two daughter cells. This process is known as mitosis, and occurs in cell division and growth processes. Two new nuclei are formed, along with identical cells. These are the same as the parent cell and the chromosome number (2n) is maintained.
Conversely in meiosis, the number of chromosomes (2n) is halved through meiotic divisions, producing 4 (n) germ cells (sperm or eggs), each containing half the number of chromosomes as its parent cell.
- crossing over: the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.
- independent assortment in metaphase I of meiosis: chromosomes align independently and genes segregate independently into new combinations ...in humans 2n, n = 23, 8 million combinations of chromosomes possible
- randomized fertilization: sperm cells fertilize an ovum to form a zygote. This occurs randomly by chance, to result in a complete set of chromosomes 2n, that is a novel combination of half each parent's number of chromosomes
Learn more about mitosis at brainly.com/question/4303192
Learn more about transcription at brainly.com/question/11339456
Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316
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Out of the following given choices;
a.phenothiazines and butyrophenones<span>
b. tricyclics and MAOIs
c. nitrates and glucocorticoids
d. benzodiazepines and antihistamines</span>
The answer is a. butyrophenones work by inhibiting dopamine-mediated
neuro-transmitters hence altering the normal thought pattern of its patients.
They are more anti-dopamine (and less
anti-adrenergic, anti-histaminic and anti-cholinergic) than phenothiazine but work in the same pharmacological
way.
