Answer:
a. The polarity of membrane phospholipids.
Explanation:
Phospholipids are the amphipathic lipids with polar heads and non-polar tails. The non-polar tails of two lipid layers form the core of the membrane while their heads are oriented towards both of the faces of the membrane. The polarity of the phospholipids does not affect the transport of substances. If a membrane has more of the saturated phospholipid tails in its core, the tight packing of the tails makes the membrane less permeable for large and polar substances.
On the other hand, a membrane with a greater proportion of unsaturated hydrocarbon tails in its core is more permeable. Cholesterol is also an amphipathic sterol and moderates the fluidity of membrane and thereby affects its permeability. A more fluid membrane is more permeable than a more solid membrane. Temperature affects the membrane polarity by affecting the membrane fluidity.
Answer:
Because DNA molecules are extremely long.
Explanation:
DNA molecule is made up of only four types of nucleotides that are adenine, guanine, cytosine, and thymine. These four types of nucleotide encode all the information necessary for the formation and working of the entire organism because each DNA strand is as long as 2 meter which contains millions of base pairs.
The four nucleotides are arranged in the DNA strand with many different combinations which results in the formation of codons sequence that contains all the information about the cell. This long DNA is compressed several times to fit in the nucleus.
The answer is Temperate Coniferous Forest. Hope this helps!
b, f, h.
The bacteria that you would not use a Gram stain on are Escherichia coli, Pseudomonas spp. and Clostridium spp, and Neisseria meningitidis.
<h3>
What are Gram stain negative bacteria?</h3>
Gram-negative bacteria have cell walls with thin layers of peptidoglycan and high lipid content.
This causes them to appear red to pink under a Gram stain.
<h3>Examples of Gram - negative bacteria</h3>
Gram-negative bacteria include:
- Pseudomonas,
- Klebsiella,
- Proteus,
- Salmonella,
- Providencia,
- Escherichia,
- Morganella,
- Aeromonas
- Citrobacter
- Neisseria meningitides
Thus, the bacteria that you would not use a Gram stain on are Escherichia coli, Pseudomonas spp. and Clostridium spp, and Neisseria meningitidis.
Learn more about gram negative bacteria here: brainly.com/question/1194544
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