Whales, humans, lizards, and birds each have forelimbs that are adapted for different functions, including swimming, using tools
, walking, and flying. While different in function, these forelimbs share a similar skeletal structure of the humerus, radius, and ulna. How does a comparison of the forelimbs of these organisms provide evidence for evolution? A. These homologous structures indicate that these four organisms all share a common ancestor.
B. These analogous structures indicate that whales are descended from organisms that lived on land.
C. These analogous structures indicate that these four organisms all experienced convergent evolution.
D. These homologous structures indicate that humans, whales, and birds all evolved from a lineage of lizards.
A. These homologous structures indicate that these four organisms all share a common ancestor.
Explanation:
Homologous structures mean the organs will have similar structure, but not necessarily function (human arm vs whale's flipper). While analogous structures are similar in function but not structure (wings of an airplane vs wings of a bird). Since the question states that they are similar in skeletal structure, we know they must be homologous structures, thereby eliminating B and C. D is not a choice because the question does not provide anything about the order of evolution. Therefore the answer is A. These homologous structures indicate that these four organisms all share a common ancestor.
This supports Darwin's theory of evolution, which states that simple life forms gradually evolved into more complex ones. Evidence for early forms of life comes from fossils. By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.
Even with treatment, up to 1 in 3 people with necrotizing fasciitis die from the infection. Six out of every 10 people who get both necrotizing fasciitis and streptococcal toxic shock syndrome at the same time die from their infection
There is little to no sunlight in the aphotic zone.
Explanation:
The aphotic zone is the deepest part of a lake/ocean, so no light is able to penetrate into those depths. Without light, photosynthetic organisms will not be able to undergo photosynthesis and will therefore not be able to survive.
This is because they lost nearly 30 to 50 ml of blood every month during menstruation and some even 80 ml. And also the metabolism of females is lower than males due to low rbc count in hormones.
