Evolution | Unit Test - 4 Sets of PDF QPs in one page with answer key I Class 12

➡️ Unit Test - 4 Sets of PDF QPs Download

Set A - Max. score: 15

1. Name the theory which says units of life (spores) were transferred to different planets including earth. (1)
2. De Vries conducted experiments in the plant called ………………. (1)
3. Distinguish between Homologous organs and analogous organs. (2)
4. Mention any 4 factors that affect Hardy-Weinberg equilibrium. (2)
5. Distinguish between Darwinian variation & mutation. (2)
6. How do Paleontological (Fossil) studies provide evidence in favor of evolution? (2)
7. Briefly explain Miller experiment. (2)
8. Observe the figure given below. .

   

   1. Identify the birds.
   2. What phenomenon in evolution is represented in the picture?
   3. Explain the phenomenon with the help of an additional example. (3)

Set A - ANSWER KEY

1. Theory of Panspermia (Cosmic theory)
2. Evening primrose.
3. Homologous organs are the organs having fundamentally similar structure and origin but different functions.
   Analogous organs are the organs having similar function but different structure & origin.
4. Gene migration, Genetic drift, Mutation, Genetic recombination and Natural selection.
5. Darwinian variation is minor, slow and directional. It results in gradual evolution.
   Mutational variation is sudden, random & directionless. Here, speciation is by saltation (single step, large mutation)
6. Analysis of fossils in sedimentary rock layers showed that life forms varied over time and certain life forms are restricted to certain geological time spans. It indicates evolution.
7. Miller created a condition like that of primitive earth (i.e., high temperature, volcanic storms, reducing atmosphere with CH4, NH3, H2O, H2 etc). He made electric discharge in a closed flask containing CH4, NH3, H2 and water vapour at 800o C. As a result, some amino acids were formed.
8. 1. Darwin’s finches.
   2. Adaptive radiation.
   3. Adaptive radiation is the evolution of different species from an ancestor in a geographical area starting from a point and radiating to other areas of geography (habitats). E.g.
      • Australian marsupials (Marsupial radiation).
      • Placental mammals in Australia.

Set B - Max. score: 15

1. 2 mya: Homo habilis      1.5 mya: ………………. (1)
2. Which theory says that life came out of decaying and rotting matter like straw, mud etc.? (1)
3. Distinguish Divergent evolution and convergent evolution. (2)
4. What is adaptive radiation? Give an example. (2)
5. Briefly explain the Theory of Inheritance of Acquired characters with suitable example. (2)
6. Arrange in correct sequence of evolution:
   Homo erectus, Ramapithecus, Australopithecus, Homo sapiens, Neanderthal man. (2)
7. 1. Identify the types of natural selection A and B. (2)

   

   2. What is meant by Founder effect?
8. p2 + 2pq + q2 = 1 is an equation regarding a principle.
   1. Name and define the principle.
   2. What do p2, 2pq and q2 indicate?
   3. What is the significance of disturbances occurring in the genetic equilibrium? (3)

Set B – Answer key

1. Homo erectus
2. Theory of spontaneous generation (Abiogenesis)
3. Divergent evolution: The evolution by which related species become less similar to survive and adapt in different environmental condition.
   Convergent evolution: The evolution by which unrelated species become more similar to survive and adapt in similar environmental condition.
4. Adaptive radiation is the evolution of different species from an ancestor in a geographical area starting from a point and radiating to other areas of geography. E.g. Australian marsupials (Marsupial radiation), Placental mammals in Australia.
5. It states that evolution of life forms occurred by the inheritance of acquired characters developed by use & disuse of organs.
   E.g. Long neck of giraffe is due to continuous elongation to forage leaves on trees. This acquired character inherited to succeeding generations.
6. Ramapithecus → Australopithecus → Homo erectus → Neanderthal man → Homo sapiens
7. 1. A= Directional selection      B= Disruptive selection.
   2. Sometimes, the change in frequency due to genetic drift is so different in the new sample of population that they become a different species. The original drifted population becomes founders and the effect is called founder effect.
8. 1. Hardy-Weinberg Principle. It states that allele frequencies in a population are stable and is constant from generation to generation in the absence of disturbing factors.
   2. p2= Frequency of homozygous dominant individuals.
      2pq= Frequency of heterozygous individuals.
      q2= Frequency of homozygous recessive individuals.
   3. Change of frequency of alleles in a population disturbs Hardy-Weinberg equilibrium. This change is due to evolution.

Set C - Max. score: 15

1. Theory of Chemical evolution was proposed by ……… (1)
2. Natural selection: Charles Darwin
   Inheritance of acquired characters: ………………. (1)
3. Distinguish between gene migration & genetic drift. (2)
4. 1. Mention the two key concepts of Darwinian theory.
   2. What is the drawback of Darwinism? (2)
5. Fossil studies provide evidence in favor of evolution. Justify. (2)
6. Complete the boxes with suitable words given: (2)
   [Analogous, Homologous, Convergent evolution, Divergent evolution]



7. Now- a- days many antibiotics are not found to be so effective to control the bacterial infection. Give a scientific explanation for this phenomenon based on evolution. (2)
8. Mention the features of the following human species. (Any 2 features for each). (3)
   1. Homo habilis
   2. Homo erectus
   3. Neanderthal man

Set C – Answer key

1. Oparin and Haldane.
2. Lamarck.
3. Gene migration: Gene flow from one population to another. Here gene frequencies change in both populations.
   Genetic drift: The gene flow by chance causing change in frequency.
4. 1. Branching descent and Natural selection.
   2. Darwin ignored about origin of variation and mechanism of evolution or speciation.
5. Analysis of fossils in sedimentary rock layers showed that life forms varied over time and certain life forms are restricted to certain geological time spans. It indicates evolution.
6. A= Homologous, B= Divergent evolution, C= Analogous, D= Convergent evolution
7. The reduced effectiveness of the antibiotic is due to the evolution of antibiotic resistance in the bacteria. i.e., natural selection by anthropogenic action.
   Over time, bacteria that can survive the antibiotic treatment reproduce and pass on their resistant traits. As they become more common, the antibiotic loses its effectiveness.
8. 1. Homo habilis: First human-like being (hominid). Brain capacity: 650-800 cc. Did not eat meat.
   2. Homo erectus: Large brain (900 cc). Ate meat.
   3. Neanderthal man: Brain capacity: 1400 cc. Used hides to protect their body. Buried their dead.

Set D - Max. score: 15

1. Homo habilis: 900 cc      Neanderthal: …………. (1)
2. Chemical evolution theory was experimentally proved by ………………. (1)
3. Suggest any two examples supporting evolution by natural selection by anthropogenic action. (2)
4. Give two examples each for homologous and analogous organs. (2)
5. Distinguish between Biogenesis and Panspermia. (2)
6. 1. Mention the equation regarding Hardy-Weinberg principle.
   2. What is meant by Genetic equilibrium? (2)
7. Identify and explain the phenomenon given below. (2)



8. Briefly explain how natural selection leads to the evolution of new species according to Darwin. (3)

Set D- Answer key

1. 1400 cc
2. S.L Miller.
3. Industrial melanism: Dark-coloured peppered moths became more common in industrial areas.
   Antibiotic resistance: Bacteria develop resistance to antibiotics due to their overuse.
   Pesticide resistance: Insects develop resistance to pesticides due to their overuse.
4. Homologous organs: Forelimbs of humans and whales; forelimbs of bats and cheetahs.
   Analogous organs: Wings of butterflies and birds; flippers of penguins and dolphins.
5. Biogenesis states that life originates from pre-existing life.
   Panspermia states that life originated outside Earth and reached Earth in the form of spores.
6. 1. p2 + 2pq + q2 = 1
   2. The gene pool (total genes and their alleles in a population) remains a constant. This is called genetic equilibrium (Hardy-Weinberg equilibrium).
7. Adaptive radiation/ Marsupial radiation.
   Adaptive radiation (evolution by adaptation) is the evolution of different species from an ancestor in a geographical area starting from a point and radiating to other areas of geography (habitats).
   Different types of marsupials were evolved from an ancestor but all within the Australian island continent.
8. Natural selection is based on the facts such as heritable minor variations within populations, limited natural resources, stable population size etc.
   Theoretically, population size grows exponentially due to maximum reproduction (E.g. bacterial population).
   But due to limited natural resources, competition occurs among organisms for resources. So population size is limited. Only some organisms survive and reproduce. It leads to a change in population characteristics and new forms appear.