The study of artificial selection by Darwin helped him to establish his theory of evolution via natural selection. One of the animals Darwin examined in detail was the domestic rock pigeon. In the 1850s breeding of pigeons was an ancient past time, thus, Darwin decided to keep and breed the pigeons by himself.
While studying pigeons, Darwin established scrupulous determinations of their skeletons and wondered at the breeds' distinct colors, behaviors, and proportions. He also observed the patterns of inheritance of various features, and he demonstrated that birds of very distinct breeds can, however, generate fertile offspring. Thus, supporting the theory that they all originated from a single species.
Answer:
The correct answer is - XDXd and XD Y
Explanation:
Sex-linked disorders are the disorders that are expressed only when there is two copy of the mutated allele or have not masked by the dominant allele of the gene. In DMD, the dominant allele is XD and the mutated allele is Xd. To express it there are the following genotype possible-
in women XdXd, and in men XdY, so these two genotypes are not possible for the parents in this case. If a mutated allele is present with the dominant allele it will be considered as carrier women but diseased will not be found in them.
So the correct genotype would be
mother: XDXd ( a carrier woman)
father : XDY (normal man)
The correct answers are:
Trematodes are acoelomates that have effective defenses against attack by their hosts' immune system.
Trematodes are flatworms, internal parasites known as flukes. Their life cycle is complex: they sexually reproduce in vertebrates and asexual reproduce in mollusks (mostly snail). The body of flukes is covered with tough tegument that defends them form digestive enzymes of host’s intestine.
Cnidarians are diploblasts that produce complex, capsule-like organelles.
Cnidaria are water organisms with simple structure: two layers of epithelium and a jelly substance between them. The cells of Cnidaria-cnidocytes contain capsule with venom substance in it with protective role.
It measures the oceans depth!
