Answer:
double helix
Explanation:
Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix
Transport of a substance from the lumen (cavity) of an organ into one side of a cell and out the other side of the cell into the extracellular fluid is called <u>transcellular transport</u>.
The two routes of transport of substances across the epithelium of the gut are by transcellular method and paracellular method.
Transcellular transport refers to the transport of solutes across a epithelial cell layer through the cells. The best example is the movement of glucose from the intestinal lumen to the extracellular fluid by the epithelial cells. The epithelial cells use the active transport to generate the transcellular transport. Active transport refers to the transport of substances from a region of its lower concentration to a region of its higher concentration against the concentration gradient using cellular energy.
Galapagos islands are groups of island in the pacific ocean that are known to have a wide range of native animals such as giant tortoise that found no where else on earth. These native animals helped Darwin in the development of the theory of natural significance which attributes to the biological significance of the Galapagos islands. Human species is a threat to the natural wildlife on these islands mainly due to poaching and destruction of natural forests that destroys habitat and also impacts negatively on biological diversity of living organisms.
"<span>Female cones produce pollen that is trapped by the male cones’ scales" is the one among the following choices given in the question that is true of conifers. The correct option among all the options that are given in the question is the fourth option or the last option. I hope the answer helps you.</span>
Surface area is an important factor in limiting cell growth because
a. the cell can burst if the membrane becomes too large.
b. materials cannot enter the cell if the surface is too large.
c. the cell may become too large to take in enough food and to remove enough wastes.
d. waste products cannot leave the cell if the cell is too small.
Answer:
c. the cell may become too large to take in enough food and to remove enough wastes.
Explanation:
The exchange of substances with surroundings is done by cells by the process of diffusion. The rate of diffusion of substances requires the presence of a higher surface area than volume. As the cells become larger, their surface area is reduced with respect to the volume. Therefore, larger cells can not support the diffusion of substances in and out as required for its proper functioning. If cells are allowed to grow continuously, they will not be able to intake the requires materials such as food and to release the waste outside.
