Heredity and Evolution
- Only variations that confer an advantage to an individual organism will survive in a population. We agree with the statement that Only variations that confer an advantage to an individual organism will survive in a population. All the va... 2
- How is the equal genetic contribution of male and female parents ensured in the progeny? In human beings, equal genetic contribution of male and female parents is ensured in the progeny through inheritance of equal number of chro... 1
- Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. Sexual reproduction causes more viable variations due to the following reasons: Error in copying of DNA, which are not highly significant. R... 1
- What evidence do we have for the origin of life from inanimate matter? The evidence for the origin of life from inanimate matter, was provided through an experiment, conducted in 1953, by Stanley L. Miller and H... 1
- Explain the importance of fossils in deciding evolutionary relationships. Fossil provide us evidence about The organisms that lived long ago such as the time period during which they lived, their structure etc. Evo... 1
- Outline a project which aims to find the dominant coat colour in dogs. Dogs have a variety of genes that govern coat colour. There are at least eleven identified gene series (A, B, C, D, E, F, G, M, P, S, T) tha... 1
- Explain the terms analogous and homologous organs with examples. Homologus organs are those organs which have the same basic structural design and origin but have different functions. For Example: The fore... 1
- How are the areas of study - evolution and classification - interlinked? Classification involves grouping of organism into a formal system based on similarities in internal and external structure or evolutionary h... 1
- A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. This information is not sufficient. For considering a trait as dominant or recessive, we need data of at least three generations. This data... 1
- In evolutionary terms, we have more in common with (a) a Chinese school-boy. (b) a chimpanzee. (c) a spider. a) a Chinese school-boy. 2
- An example of homologous organs is (a) our arm and a dog's fore-leg. (b) our teeth and an elephant's tusks. Answer: (d) all of the above Homologous organs have the same basic structure and origin but may perform different functions. Our arm and a d... 1
- A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white Correct option is c) TtWW 2
- In evolutionary terms, can we say which among bacteria, spiders, fish and chimpanzees have a 'better' body Evolution cannot always be equated with progress or better body designs. Evolution simply creates more complex body designs. However, this d... 1
- Why are human beings who look so different from each other in terms of size, colour and looks said to belong to the same A species is a group of organisms that are capable of interbreeding to produce a fertile offspring. Skin colour, looks, and size are all var... 1
- What are fossils? What do they tell us about the process of evolution? Fossils are the remains of organisms that once existed on earth. They tell us about the development of the structures from simple structured... 1
- Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not? The wing of a butterfly and the wing of a bat are similar in function. They help the butterfly and the bat in flying. Since they perform sim... 1
- Give an example of characteristics being used to determine how close two species are in evolutionary terms. Feathers in some ancient reptiles like dinosaurs, as fossils indicate, evolved to provide insulation in cold weather. However, they cannot f... 1
- Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not No, because geographical isolation does not affect much in asexually reproducing organisms. Asexually reproducing organisms pass on the pare... 1
- Will geographical isolation be a major factor in the speciation of a self-pollinating plant species? Why or why not? Geographical isolation can prevent the transfer of pollens among different plants. However, since the plants are self-pollinating, which mea... 2
- What factors could lead to the rise of a new species? Natural selection, genetic drift and acquisition of traits during the life time of an individual can give rise to new species. 2
- Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics? The small number of members in a population of tigers do not allow large number of variation to occur which are essential to survival of the... 1
- Why are traits acquired during the life-time of an individual not inherited? This happens because an acquired trait involves change in non-reproductive tissues which cannot be passed on to germ cells or the progeny. T... 1
- What are the different ways in which individuals with a particular trait may increase in a population? Individuals with a particular trait may increase in a population as a result of the following: Natural selection: When that trait offers som... 2
- How is the sex of the child determined in human beings? In human beings, the females have two X chromosomes and the males have one X and one Y chromosome. Therefore, the females are XX and the mal... 1