The correct answer is option B. Genotype AA, phenotype-Unaffected.
The cystic fibrosis is a condition caused by the inheritance of the two recessive allele, It is an autosomal recessive disease.
In the given case, the parents are carriers, and the carriers are always heterozygotes. Hence, the phenotype of the both parent should be Aa. A possible cross of the parents is shown in the figure below.
In case, the progeny have a single dominant trait, the child would not be affected, but will be a carrier and can pass the disease to offspring. In case, the child inherit both the dominant allele (homozygous dominant) from the parents, then he/she would be unaffected. In case, the phenotype of the child is homozygous recessive then it would be affected.
Two systems most directly interact in the fuzzy millipede's defense against ants are :
<u>muscular and integumentary</u>
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Explanation:
- The fuzzy millipede, Polyxenus fasciculatus, is found in Texas and is preyed upon by most species of ants.
- Most millipedes defend themselves with a variety of chemicals secreted from pores along the body, although the tiny bristle millipedes are covered with tufts of detachable bristles.
- Due to their lack of speed and their inability to bite or sting, millipedes' primary defence mechanism is to curl into a tight coil – protecting their delicate legs inside an armoured exoskeleton.
- Reproduction in most species is carried out by modified male legs called gonopods, which transfer packets of sperm to females.
- Millipedes overwinter, so they may hide in cracks or crevices throughout the whole winter and emerge in the spring.
- These insects live in dark, damp places and feed on decaying plant life, sometimes damaging crops. But they can serve a good purpose too.
- To protect itself against the ants, it ejects fibers from a tuft located at the tail end of its body. When an ant attacks, the millipede flexes its back end toward the ant and wipes the tufts against it.
