D. Polarity and size.
<span>The size, polarity, and charge of a substance will determine whether or not the substance can cross the cell membrane by diffusion. The cholesterol was an example of a lipid, and is highly soluble in the nonpolar environment of the lipid bilayer. You saw, in the animation above, the cholesterol freely passing into the hydrophobic environment of the membrane. Cholesterol distributes freely in the membrane and then some fraction will dissolve in the aqueous environment of the cytoplasm. Water, on the other hand, while polar, is small enough to cross the membrane at a slow rate. Note that specialized transport proteins in certain cell membranes can provide a channel for the water, greatly increasing its rate of crossing the membrane. The lipid bilayer is much less permeable to the ion, because of its charge and larger size. As a general rule, charged molecules are much less permeable to the lipid bilayer.</span>
Answer:
Distinct mechanisms are used by bacteria in order to transfer the gene from one bacteria to another. These are transformation, transduction, and conjugation. Transformation refers to the process of uptaking extracellular DNA by the recipient of the other bacterial cell.
In the process of transduction, the donor DNA gets packed within the bacteriophage and infects the recipient bacteria. In the process of conjugation, the genetic substance is transferred by the donor bacteria to the recipient via the process of mating.
a. Of all these three mechanisms, transformation is the process that exhibits a broad range and can be easily performed in the lab. As in the process, there is a slight chance of rejection or failure due to direct compatibility between the bacteria.
b. While the narrowest broad range is found in the process of conjugation, as in order to transfer the genetic substance between the two bacterial species, there should be a similarity between the two species so that they can mate and exchange the genetic substance in between them.
1. Answer;
It facilitates the movement of the fetus towards the pelvic girdle thus the child is born headfirst.
Explanation:
- During labor the pelvic floor facilitates movement of the fetus towards the pelvic girdle by resisting the descent of the presenting part. This makes the fetus to rotate forwards and therefore results in majority of the fetus being born headfirst.
2. Answer;
Purple pushing lead to development of pelvic floor problems.
Explanation
;
- Purple pushing involves the midwife instructing a woman to hold her breath for ten seconds while forcefully pushing down during a contraction.
- in the second stage instead of waiting for the mother to feel the instant urge of pushing which lead to development of pelvic floor problems.
3. Answer;
Exercise can help to strengthen the abdominal muscles and reduce the appearance of diastasis recti.
Explanation;
- By contracting transversal abs muscles they strengthen and pull the muscles inwards.
- The diastasis recti reduce with time due since the rectus muscles come close to each other enabling a human being to live a normal life because flexion, bending and stability becomes easy.
4. <u>Answer</u>
- Pelvic floor muscles
- Stomach muscles
- Abdominal muscles
- Perineal muscles
- Uterine muscles
<u>Explanation</u>
- Abdominal muscles are stretched to their limit by term. They greatly decrease the ability to perform strong contraction.
- Pelvic floor is vulnerable to muscular and neurological injury during labor and delivery.
- Perineal muscle tightening strengthens the pubococcygeus muscle and increases its tone.
5. Answer and explanation;
- Sports that can lead to falling down e.g. skating
- Sports that may involve altitude change
- Exercises that involve lying flat on your back
- Exercises that involve holding o breath
- Motionless standing
6. Answer
Yes
Explanation
;
- Exercise maintains physical fitness, health and wellness aiding growth to the unborn since the mother gains enough strength and energy and there is proper blood flow.
- Many pregnant women tend to gain weight which may lead to health difficulties for example struggling to breath. The pregnant lady is able to cope with labor and she is able to get back in shape after the baby is born.
7. <u>Answer</u>;
One is supposed to get up slowly and gradually to avoid dizziness.
<u>Explanation;</u>
- Dizziness happens after a tiresome activity done continuously for a period of time thus one should get up slowly and gradually to avoid other injuries like falling endangering the life of the unborn child.
