Which option correctly describes the structure of cell walls? A)Cell walls are rigid. They block the movement of all molecules. B)Cell walls are flexible. They block the movement of all molecules. C)Cell walls are rigid. Small molecules like water or oxygen can pass through them. D)Cell walls are flexible. Small molecules like water or oxygen can pass through them.

If the sperm gamete that fertilizes an egg has a(n) _____ chromosome, it will form female offspring.

The function f(t) = 4t2 - 8t + 6 shows the height from the ground f(t), in meters, of a roller coaster car at different times t. Write f(t) in the vertex form a(x - h)2 + k, where a, h, and k are integers, and interpret the vertex of f(t). A. f(t) = 4(t - 1)2 + 3; the minimum height of the roller coaster is 3 meters from the ground

B. f(t) = 4(t - 1)2 + 3; the minimum height of the roller coaster is 1 meter from the ground

C. f(t) = 4(t - 1)2 + 2; the minimum height of the roller coaster is 2 meters from the ground

D. f(t) = 4(t - 1)2 + 2; the minimum height of the roller coaster is 1 meter from the ground

What is biodiversity an indicator of? A. ecosystem health B. ecosystem growth C. ecosystem decline D. ecosystem location

Bio homework help :)?Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees. (use to answer Q 1.) 1.What keeps the two populations separate? behavioral reproductive isolation temporal reproductive isolation lack of hybrid viability spatial reproductive isolation They are already separate species. 2. Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact? a postzygotic isolating mechanism b prezygotic isolating mechanism c gametic reproductive isolating mechanism d behavioral reproductive isolating mechanism e two of the above 3. The peppered moth provides a well-known example of natural selection. The light-colored form of the moth was predominant in England before the industrial revolution. In the mid-nineteenth century, a dark-colored form appeared. The difference is produced by a dominant allele of one gene. By about 1900, approximately 90% of the moths around industrial areas were dark colored, whereas light-colored moths were still abundant elsewhere. Apparently, birds could readily find the light moths against the soot-darkened background in industrial areas and therefore were eating more light moths. Recently, use of cleaner fuels has greatly reduced soot in the landscape, and the dark-colored moths have been disappearing. Should the two forms of moths be considered separate species?
a. Yes, because natural selection has affected the frequency of the two different forms.
b. Yes, because they have completely different coloration.
c. Yes, because they are reproductively isolated based on habitat.
d. Yes, because they have completely different coloration and natural selection has affected the frequency of the two different forms. e. No.

_____ phase is the period during the life of a cell when it has finished mitotic division.

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