Hemophilia is caused by a defect in the genes responsible for the formation of blood clotting factors viii and ix. These genes are located on the X chromosome. A female has two X chromosomes and a male has an X chromosome and a Y chromosome. Therefore, all the daughters of a hemophiliac father will be the carriers of this disease, and half of his sons acquiring the X chromosome from the father will have the disease.
Peyer's patches are located in the mucosa and extend into the submucosa of the small intestine, especially the ileum.
Observations
The first observation is overproduction. This means all species produce more offspring than will survive to become adults. Think of all the thousands of fish eggs produced each year. This means populations of species should be getting larger all the time, but they aren't, because there are mechanisms in place to curb population explosions, such as competition for food, predation, and disease. From this, Darwin was able to make a deduction: there is a struggle for existence. Many of those fish eggs are food for predators, who would not survive without them.
Darwin's second observation was variation. This means members of the same species show variation in characteristics. For example, zebras show variation in pattern and color of their stripes. Goldfish have gold scales, orange scales, or brown scales, or a mixture of all three.
Variation applies to all traits, even those essential for the survival of the individual organism. An eagle depends on excellent eyesight to locate prey, but it can still be born shortsighted. This means that variations are random and are not specific to any favorable adaptation.
The next observation, selection , means organisms that survive are more likely to reproduce and pass on favorable adaptations to their offspring than those with unfavorable adaptations. For example, height is an inheritable characteristic, and for the giraffe, having long necks (which added to their height) was reproductively advantageous. The taller giraffes were able to reach leaves in tall trees, which kept them alive longer, and able to reproduce, making them more reproductively fit than shorter giraffes who couldn't reach those leaves and died without reproducing.
The last observation Darwin made wasadaptation . This means that some traits are passed on to new generations and become common within the population, like the long neck of the giraffe. This doesn't happen overnight, it takes time for these traits to spread throughout a population.
So, what does this mean for natural selection and genetic diversity? Let's find out.
Answer:
Bulk flow
Explanation:
Generally when there is mass movements of molecules of the fluids from a high pressure gradients to low pressure gradients; that is down the concentration gradients, the process is called Bulk flow. In relation to cells, it is the exchange of material between cells through the pores of the adjoining cells. In xylem , water and minerals flow from high pressure roots to the leaves, and phloem transport food substances from the leaves the sources at high pressure to other parts of the plants.
The capillary transport mechanisms involves the movements of fluids, ions across the fenestration of the capillaries due to the hydostatic pressure of the fluid from the high pressure to the low pressure cellular environments.This is common in the glomerulus of the kidney, intestine, and some endocrine glands.
The single wall endothelial lining of capillaries forms continuous wall which allows passage of ions and fluids while restricting movements of large molecules. Generally the high pressure from the hydrostatic pressure forces these materials across the walls.
Simple diffusion which follows concentration gradient across membranes ensures distribution of substances across the walls for fast uptake by the cells.
The movement of Macromolecules across capillary wall is called vesicular transport.
Thus Bulk flow is odd.
<span>Because the atmosphere is thinner, there would be less pressure keeping the heart at its current size and it would expand and become too large to work properly</span>
