Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.
Answer:
Both ferns and flowering plants produce spores at some point in their life cycles. True
Only ferns have a gametophyte as part of their life cycle. False.
Only flowering plants produce pollen grains. true
Both a tree and a large fern plant are diploid sporophytes. True
Explanation:
Yes, both ferns and flowering plants produce spores in their life cycles. In fern plant, it produce spores on the underside of the leaves whereas in flowering plant, there are two types of spores such as microspores and megaspores. Both ferns and flowering plants have gametophyte as part of their life cycle. Flowering plants produce pollen grains whereas non-flowering plants produce spores to continue their generation. Both tree and large fern plants having diploid sporophytes which is a necessary part of their life cycle.
Populations
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ecosystem
biosphere
Chloroplasts are small, disc-like, and green.
