Answer:
<em>This is an example of natural selection (adaptation).</em>
Explanation:
Natural selection tends to favor those organisms which are better adapted to live in an environment.
As tortoises having flat shell and long neck were better adapted to live in barren area, hence through natural selection those organisms were favored in such an ecosystem.
As tortoises that lived on the vegetative lands were more adapted to live in such an ecosystem, hence through natural ecosystem these organisms were favored and increased in numbers.
A demarc is where one network ends and another begins. Demarc stands for demarcation point. It is the physical point at which the public network of a telecommunications company ends and the private network of a customer begins.
However, the distinction between where one category of network begins and another ends is sometimes blurry.
Answer:
Sexual reproduction involves two parents and the joining of male and female gametes during fertilisation. The offspring inherit a mixture of genes from both parents, so are different to each other and their parents. In asexual reproduction there is only one parent. The offspring are clones of the parent and each other.
Explanation:
B) protein channel
Lipids are composed of fatty acids which form the hydrobic tail and glycerol which forms the hydrophilic head; glycerol is a 3-Carbon alcohol which is water soluble, while the fatty acid tail is a long chain hydrocarbon (hydrogens attached to a carbon backone) with up to 36 carbons.
Their polarity or arrangement can give these non-polar macromolecules hydrophilic and hydrophobic properties. Via <em>diffusion,</em> small water molecules can move across the phospholipid bilayer acts as a semi-permeable membrane into the extracellular fluid or the cytoplasm which are both hydrophilic and contain large concentrations of polar water molecules or other water-soluble compounds. The hydrophilic heads of the bilayer are attracted to water while their water-repellent hydrophobic tails face towards each other- allowing molecules of water to diffuse across the membrane along the concentration gradient.
Transmembrane proteins are embedded within the membrane from the extracellular fluid to the cytoplasm, and are sometimes attached to glycoproteins (proteins attached to carbohydrates) which function as cell surface markers. Carrier proteins and channel proteins are the two major classes of membrane transport proteins.
- Carrier proteins (also called carriers, permeases, or transporters) bind the specific solute to be transported and undergo a series of conformational changes to transfer the bound solute across the membrane. Transport proteins spanning the plasma membrane facilitate the movement of ions and other complex, polar molecules which are typically prevented from moving across the membrane.
- Channel proteins which are pores filled with water versus enabling charged molecules to diffuse across the membrane, from regions of high concentration to regions of lower concentration. This is a passive part of facilitated diffusion
Learn more about membrane components at brainly.com/question/1971706
Learn more about plasma membrane transport at brainly.com/question/11410881
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Answer:
The correct answer is "5-1-3-2-4".
Explanation:
Internalization of LDL particles into cells, is needed to form the intracellular vesicles known as endosomes. The order of events that allow for this process are:
5) LDL receptors migrate to the cell surface and cluster in clathrin-coated pits. Clathrin acts directing the receptors to the cell membrane region where endosomes are formed.
1) A combination of cholesterol and apolipoprotein binds to LDL receptors and becomes internalized as endocytotic vesicles. Once the receptors are in the proper cell membrane region, cholesterol and apolipoprotein are bound and internalized.
3) Several endocytotic vesicles fuse to form an endosome.
2) The environment of the endosome becomes acidic, which causes the LDL to dissociate from its receptor; additionally, the endosome fuses with a lysosome. LDL should be dissociated from its receptor since it is going to be degraded in the following step.
4) The LDL particle is degraded by the lysosome. This takes place after endocytosis, when LDL particles are transported into lysosomes once they are fused, cleaving the cholesterol esters into cholesterol and fatty acids.
