Apatient visits your clinic often with recurrent respiratory infections. based upon their medical history, it appears they have been an active smoker for over 40 years. select the statement that most accurately reflects how this information may reveal why the patient is highly susceptible to respiratory pathogens:

1. smoking decreases the formation and effectiveness of complement proteins.
2. smoking can paralyze the ciliary escalator.
3. smoking directly inhibits b- and t-cell action.
4. smoking decreases the activity of neutrophils.

Smoking can paralyze the ciliary escalator.

Explanation:

Respiratory infections affects the sinuses, lungs, chest and nose. Chronic infections occurs repeatedly over time. Bacteria and virus may also acts as pathogen for the respiratory infections.

The main reason of the respiratory infection is the presence of harmful chemical in smoking. The motile cilia connects the ciliary escalator with the trachea and respiratory system. The harmful toxins and chemicals in smoke can paralyze the ciliary escalator.

Thus, the correct answer is option (2).

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation: