7. Answer the following questions.
a. How are the hereditary changes responsible for evolution?
b. Explain the process of formation of complex proteins.
c. Explain the theory of evolution and mention the proof supporting it.
d. Explain with suitable examples importance of anatomical evidences in evolution.
e. Define fossil. Explain importance of fossils as proof of evolution.
f. Write evolutionary history of modern man.
and give me answers in point vise
Answers
Explanation:
Evolution is the gradual change occurring in the living organisms over a long duration. New species are formed due to changes in the specific characters of several generation and are selected by the nature to survive. Thus hereditary changes are responsible for the evolution.
Answer:
a) ans :-- Heredity is the passage of traits from parents to their offspring derived from sexual or asexual reproduction.
b) ans:-A protein is a Quaternary structure. It is made up of two or more polypeptide chains. Complex proteins are made up of various protein molecules which are linked by non-covalent bonds. Amino acids are the basic units of the proteins. They link together to form a primary structure, polypeptide chain. Secondary structure is made up of beta sheets or alpha helices. This structure then folds into a three-dimensional structure called as tertiary structure. The protein structure binds with a non-protein moiety to form a Quaternary structure called as complex protein.
c) ans:-Studies show that if two or more species have a large number of similarities, then they somehow tend to live near to each other.
Fossils are the naturally preserved body parts or remains or impressions of the body.
d) ans:-The study of comparative anatomy predates the modern study of evolution.
Organisms with similar structures must have acquired these traits from a common ancestor. It can serve as the first line of reasoning in determining the relatedness of species. It's important examples are :
Homologous organs - All mammals share the same pattern of forelimbs. Though they perform different functions, they are anatomically similar. This is called divergent evolution and the structures are called homologous structures (common ancestors).
Analogous organs - The pair of organs is not anatomically similar, but performs the same function (e.g., the wings of butterflies and birds). This is called convergent evolution.
e) ans:-i. Fossils are remnants and impressions of organisms that remain preserved underground. <br> ii. Carbon consumption of animals and plants stops after death and only the decaying processes of C-14 takes place continously. <br> iii. The ratio of C-14 to C-12 changes constantly with time as C-12 is non radioactive in dead plants and animals. <br> iv. The time passed since the death of a plant or animal can be calculated by carbon dating i.e. by measuring the radioactivity of C-14 and ratio of C-14 to C-12 present in the remains of the dead organism. <br> v. The oldest fossils are buried deep in the Earth's crust, while the younger ones occupy the upper surfaces. Hence, fossils of invertebrates are found buried deep as they are very old and belong to the Palaeozoic era. The fossils of Pisces, Ambhibians and Reptiles were obtained in the consecutive layers. The Mesozoic era was dominated by reptiles, while the Cenozoic era showed presence of mammals and brids. <br> vi. Thus, study of fossils is an important aspect of evolution since it can be used in the paleotology and anthropology for determining age of the fossils and deducing information about their ancestors.
f) ans:-Modern man (homo sapiens ) have evolved from ancestors which were common to both apes and humans.
Dryopithecus is considered to be the common ancestor of apes and man.
dryopithecus evolved to Ramapithecus.
then a series of ancestors were present.. like
australopithecus, homo habilis, homo erectus java man, Peking man, Heidelberg man, Neanderthal man and lastly cro-magnon man.
crop magnon man was then evolved to become the modern man.
In evolution we can observe that the main difference in the cranial capacity. the cranial capacity increased with evolution of man.
we can also observe the development of culture, hunting habits, and tool making skills.