Heredity and evolution Worksheet-15

Heredity and evolution Worksheet-15


  1. What is Mendel's genetics?


  1. What is inherited trait?


  1. Do offsprings and their parents have the same traits?


  1. What type of reproduction give rise to more number of successful variation?


  1. What is the basis of evolution?


  1. What is gene flow?


  1. Define hierarchy.


  1. Define characteristic of organisms.


  1. What is classification?


  1. What are the various kinds of fossils?


  1. What is adaptation?


  1. What is phylogeny?


  1. What is environmental selection?


  1. What is acquired trait?


  1. Define speciation.


  1. What is artificial selection?


  1. What is the main reason for evolution according to Darwin?


  1. What gave rise to life originally?


  1. What is the basic unit of life?


  1. What is the basic characteristic difference of cell design?


  1. 'Older fossils are found closer to the surface' - True or false.


  1. What is the sex chromosome pair of male?


  1. What is the sex chromosome pair of female?


  1. What will be the sex of a child who inherits X chromosome from his/her father?


  1. What will be the sex of a child who inherit Y chromosome from his/her father?


  1. State which of the following are homologous and which are analogous -

(a) Wings of bird and an insect

(b) Forelimbs of frog, a reptile, a bird and a human.

(c) Flippers of whale and fins of fish

(d) Tail of chameleon and hand of man

(e) Flippers of whale and wings of bat.


  1. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?


  1. A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits - blood group A or O - is dominant? Why or why not?



  1. Mendel’s genetics deals with the genes passing on to generations.


  1. Inherited traits is the transmission of particular characteristics from parents to their offsprings, generation to generation, which bear all basic features with great deal of variation. Inherited trait is therefore, a particular genetically determined characteristics that distinguishes a person.


  1. Yes.


  1. Sexual reproduction.


  1. Selection of variants by environmental factors forms the basis of evolution.


  1. Gene flow is the exchange of genetic material by interbreeding between populations of the same species or between individuals within a population. Gene flow increases the variation in the genetic composition of a population.


  1. Hierarchy is a type of social organisation in which individuals are ranked according to their status or dominance relative to other group members. Higher up in the hierarchy the similarities between members of a group become fewer.


  1. Characteristic is the detailed appearance or behaviour of a particular form or a particular function. For example, the four limbs of human beings is a characteristic and that plants can perform photosynthesis is also a characteristic.


  1. Classification is the arrangement of organisms into a series of groups based on physiological, biochemical, anatomical or other relationships.


  1. Kinds of Fossils fossils are of various kinds depending upon their differences in appearances and degrees of detail and preservation. They are - Fossil tree trunk, Fossil invertebrate (Ammonite), Fossil invertebrate (Trilobite) Fossil fish (Knightia) and Fossil dinosaur skull (Rajasaurus).


  1. Adaptation is any change in the structure or functioning of an organism that makes it better suited to its environment.


  1. Phylogeny is the evolutionary history of an organism or group of related organisms.


  1. Environmental selection is the selection within a population resulting from the influence exerted by the environment. It leads to a change in the composition of genes within a population.


  1. Acquired Trait is a particular characteristic that is developed during the lifetime of an individual. Such characteristics are not genetically controlled and cannot be passed on to the next generation.


  1. Speciation is the evolution of reproductive isolation among once - interbreeding populations, i.e., the development of one or more species from an existing species.


  1. Artificial selection is the modification of species by selective breeding. Animals or plants with desirable characteristics or traits are interbred with the aim to produce new strain of organisms for a specific purpose.


  1. According to Darwin evolution took place due to natural selection.


  1. Life must have developed from the simple inorganic molecules which were present on earth after it was formed.


  1. Cell is the basic unit of life in all organisms.


  1. The basic characteristic of cell design that differs among different organisms is whether the cell has a nucleus. Bacterial cells do not, while the cells of most other organisms do.


  1. False.


  1. The sex chromosome pair of male has one X chromosome and one Y chromosome i.e., half of the male gametes or sperms will have X chromosome and the other half will have Y chromosome.


  1. The sex chromosome pair of female has two X chromosome i.e., all the female gametes or ova will have only X chromosomes.


  1. The sex of the child will be a boy.


  1. (a) Analogous, (b) Homologous, (c) Analogous, (d) Analogous, (e) Homologous.



  1. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, trait B is likely to have arisen earlier.


  1. Why are traits acquired during the life-time of an individual not inherited?