The correct answer is (a.) Its spindle-shaped cells allow it to do smooth muscles. The structure of the cardiac muscles which is spindle-shaped is very important for the heart to withstand the stretching of the muscles during the contractions. Also for its smooth surface which is very important to prevent any possible blood clot during circulation.
B. atmosphere since the atmosphere is made up of o2, co2 (a greenhouse gas) and nitrogen. those are the primary elements
I think it’s
C, decreased sources diversity
From the
books of Geography Seattle is well known for its rain and dark, gloomy skies, but
it may surprise many how pleasant the weather can be, particularly during the
summer months. Using data from meteorological services for the past 50 years,
we can conclude that November through March brings cool temperatures, heavy
cloud cover and rain falling on most days. The coldest month is January with
average lows in the mid to upper 30s F (about 3°C). Weather is pleasant from
April through October, with the best weather in July and August when highs
average in the 70s and rain is uncommon. Skies are mostly clear and smog-free,
though mornings can produce an on-shore flow resulting in low clouds and fog
which typically burns off by mid-day.
Answer:
c. a high percentage of very long chain saturated fatty acids
Explanation:
Saturated fatty acids do not have double bonds (they are saturated with hydrogens), so their tails are relatively straight. Unsaturated fatty acids, on the other hand, contain one or more double bonds, which often produces an elbow or bend. (You can see an example of an unsaturated bent tail in the phospholipid structure diagram that appears at the beginning of this article.) Saturated and unsaturated phospholipid fatty acid tails behave differently when the temperature drops:
- At colder temperatures, the straight tails of saturated fatty acids can be tightly bound, producing a dense and quite rigid membrane.
- Phospholipids with unsaturated fatty acid tails cannot bind so closely due to the bent structure of their tails. For this reason, an unsaturated phospholipid membrane remains fluid at lower temperatures than a saturated phospholipid membrane.
Most cell membranes contain a mixture of phospholipids, some with two saturated (straight) tails and others with a saturated tail and an unsaturated (folded) tail. <u>Many organisms — fish, for example — can adapt physiologically to cold environments by changing the proportion of unsaturated fatty acids in their membranes, that is, increasing the proportion of saturated long-chain fatty acids.</u>
In addition to phospholipids, animals have an additional component in their membrane that helps them maintain fluidity. Cholesterol, another type of lipid that is embedded between the membrane phospholipids, helps decrease the effects of temperature on fluidity.
