Homologous organs have

Homologous organs are those organs that have the same fundamental structures but are different in functions. These organs follow the same basic plan of organization during their development. But in adult condition, these organs are modified to perform different functions as an adaptation to different environments. These structures are a result of divergent evolution. These structures are a result of divergent evolution. Homology indicates common ancestry. Examples of homologous structures are: (i) forelimbs of man, horse, whale and bat

Denise DeCooman Denise DeCooman was a teaching assistant for the General Zoology course at California University of Pennsylvania while she earned her Master's of Science in Clinical Mental Health Counseling from fall semester of 2015 and spring of 2017. She also has a Bachelor's of Science in Biological Sciences from California University. She has been writing instructional content for an educational consultant based out of the greater Pittsburgh area since January 2020. • Instructor The term, 'homologous' is from Greek origin and can be broken down into the root words of 'homo-', which means 'the same' and '-logous' which can be translated as 'proportion' or 'ratio'. When asking the question, 'what are homologous structures or traits?', know that what is being referred to are certain physical characteristics that are shared by different species. Homologous structures in different species may have slightly or very different functions. In order to be considered homologous, anatomical structures must develop from the same embryonic tissue. Homologous vs. Analogous Let's take a look at the world, specifically the mammals, around us. Look closely. What similarities do you see? Well, the first one that strikes me is we all have a similar shape. We all have a head, a body and some form of arms and legs, right? In some cases, those parts are similar in structure, function or both. For example, the bones in the legs of a horse and donkey are similar in both structure and function....

Organs, which have a common fundamental anatomical plan and similar embroyonic origin whatever varied functions they may perform are regarded as homologous organs. For instances the flippers of a whale, a bats wing, fore-limb of a horse, a birds wing and forelimbs of human are structurally as well as functionally different . Whale’ this flippers help in swimming, wings of birds and bat are used in flying, horse’ this forelimb help in running and human’s hand is meant for grasping. They are structurally modified accordingly. However, anatomically they have similar bones, humerus in the upper arm, radius ulna in the forearm, carpals and metacarpals in the wrist and hand. Presence of homologous organs in different groups of animals indicates their common origin or ancestry and degree of closeness to difference among various groups.

Homology of the male and female genitalia Author: Lorenzo Crumbie MBBS, BSc • Reviewer: Latitia Kench Last reviewed: March 09, 2023 Reading time: 12 minutes There are often many phenotypical differences between males and females of a particular species. These include differences in height, body mass, muscle tone, hair length, and in non-human species, skin or feather pigmentation. The most emphasized difference between the two members of the species is the capability (or lack thereof) to bear offspring. This difference would subsequently suggest that there would also be a difference between the structure of the male and As a result, embryological origins, as well as internal and external structures, along with some clinically relevant points, will be explored. Embryological homology Primitive sex cords Although the genotypic sex of the individual is determined at the time of fertilization (46 XX or XY), phenotypic expression of sexual dimorphism in humans is subject to a myriad of genetic pathways. Furthermore, even though the end results appear structurally different, there are a lot of similarities between males and females embryologically. Both genital ridge, is infiltrated by primordial germ cells around the sixth gestational week. The arrival of these cells has been credited with the induction of gonadal differentiation. Additionally, as the primordial germ cells enter the gonadal ridge, the mesenchyme deep to the ridge is penetrated by the ridge’s proliferating primi...

\( \newcommand\) • • • Learning Objectives • Distinguish homologs, orthologs and paralogs Homology forms the basis of organization for comparative biology. A homologous trait is often called a homolog (also spelled homologue). In genetics, the term “homolog” is used both to refer to a homologous protein and to the gene ( DNA sequence) encoding it. As with anatomical structures, homology between protein or DNA sequences is defined in terms of shared ancestry. Two segments of DNA can have shared ancestry because of either a speciation event (orthologs) or a duplication event (paralogs). Homology among proteins or DNA is often incorrectly concluded on the basis of sequence similarity. The terms “percent homology” and “sequence similarity” are often used interchangeably. As with anatomical structures, high sequence similarity might occur because of convergent evolution, or, as with shorter sequences, because of chance. Such sequences are similar, but not homologous. Sequence regions that are homologous are also called conserved. This is not to be confused with conservation in amino acid sequences in which the amino acid at a specific position has been substituted with a different one with functionally equivalent physicochemical properties. One can, however, refer to partial homology where a fraction of the sequences compared (are presumed to) share descent, while the rest does not. For example, partial homology may result from a gene fusion event. Figure: Example of Homologou...

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Medical News Todayonly shows you brands and products that we stand behind. Our team thoroughly researches and evaluates the recommendations we make on our site. To establish that the product manufacturers addressed safety and efficacy standards, we: • Evaluate ingredients and composition:Do they have the potential to cause harm? • Fact-check all health claims:Do they align with the current body of scientific evidence? • Assess the brand:Does it operate with integrity and adhere to industry best practices? We do the research so you can find trusted products for your health and wellness. Share on Pinterest How much do you know about the clitoris? The clitoris has long been misrepresented and misunderstood, and even now, it still holds some riddles that science is yet to solve. All female mammals — and some female birds and reptiles — have a clitoris ( However, it is not clear if or how many of them also orgasm thanks to this organ. In humans, the clitoris has been firmly tied to sexual pleasure, though whether it plays any other role is still a matter for debate. Despite approximately half the world’s population being born with a clitoris, this sexual organ is not talked about very much, and, until very recently, even the information that we might have found about it in textbooks was incorrect or misleading. So, what is there to know about this elusive organ, and why are we still struggling to understand it? Read on to find out. Share on Pinterest This is a 3-D printed model...

Hint:Evolution is unrolling or unfolding of nature that brings about an orderly change from one form or condition to another, resulting in descendants becoming different from ancestors. Evidence supporting evolution are - homologous organs, analogous organs, vestigial organs, and paleontological evidence. Complete answer: >Option A: Homology is the similarity between organs of different animals based on common ancestry or common embryonic origin. Therefore, this is the correct option. Example – forelimbs of birds, bats, house, frog and human have the same basic anatomy but they all perform different functions according to their needs. The hopping legs of the frog contain the same bones as our legs, but frog legs are modified for hopping. >Option B: Organs with different origins but same function are known as analogous organs and not homologous organs. Therefore, this is the incorrect option. >Option C and D: These options are irrelevant, therefore, this is the incorrect option. Thus, the correct answer is option (A) Same origin, different function. Note: Homology provides evidence for evolution as it indicates common ancestry and divergent evolution. In developmental biology, organs are developed in the embryo in the same manner. Other examples of homologous organs are – >Tailbones of human beings and the tail of a monkey. >Pelvis of a dog, of a cat and of a human and of a snake are homologous structures. >Forelimbs of frog, bird, rabbit and lizard look very different as t...