b. The placenta passes oxygen, nutrients, and other useful substances from the mother to the fetus.
c. The placenta mixes blood from the mother and fetus together.
d. The placenta protects the mother from being attacked by the fetal immune system.
Answer:
The correct answer would be - Hydrangea plants depend on the concentration of some element which is affected by the acidic or basic nature of the soil.
Explanation:
Hydrangeas plants produce two different type of flowers blue and pink. The color of the plant depends on the pH of the soil or the acidic or basic nature of the soil. If the pH of the soil is acidic which means 5.5 or less the color of the flower would be blue and if it is near or above the 6.5 flowers would be pink.
So, it is clear that the concentration of any element that affected by the pH of the soil is responsible for the color of the flowers, in this case, it is found that the concentration of aluminum ions (Al+++) in the soil. When the soil is alkaline less concentration aluminum available for the plant and more available to the plant when the soil is acidic.
The color of hydrangea flowers is influenced by soil pH, with acidic soil producing blue flowers, and neutral to basic soil producing pink ones.
The information given about hydrangea plants and the color of their flowers is an example of how environmental factors can affect biological characteristics. Their flower color is determined by the soil pH. Acidic soil with a pH of 5.5 or less triggers the hydrangea plants to produce blue flowers, while soil with a neutral to basic pH of 6.5 and up causes the flowers to be pink.
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B. genes.
C. cells.
D. plasmids.
Answer:
Only about 1%
Explanation:
According to the given condition, the earth is comprised of nearly 75% of water and only 25% of land.
Out of this total amount of water on earth, the water in the oceans and seas makes up 97% of it that are saline and not good for drinking purpose. The remaining 3% of water includes the fresh water such as the glaciers and ice caps on earth, groundwater and others.
Out of this total fresh water, only about 1% of water is available for drinking, which covers significantly very less amount of water on the entire earth.