(a) Precambrian era
(b) Paleozoic era
(c) Mesozoic era
(d) Cenozoic era

Ernst Von Haeckel propounded the "biogenetic law or theory of recapitulation" which states that the life history of an individual (ontogeny) briefly repeats or recapitulates the evolutionary history of the race (phylogeny). In other words "Ontogeny recapitulates Phylogeny".

(i) Darwin failed to explain the mechanism of variation.
(ii) Darwinism explains the survival of the fittest but not the arrival of the fittest.
(iii) He focused on small fluctuating variations that are mostly non-heritable.
(iv) He did not distinguish between somatic and germinal variations.
(v) He could not explain the occurrence of vestigial organs, over specialization of some organs like large tusks in extinct mammoths, oversized antlers in the extinct Irish deer, etc.,

Methane, carbondioxide, ammonia and water vapour.

(i) Urey and Miller (1953), paved way for understanding the possible synthesis of organic compounds that led to the appearance of living organisms.

(ii) In their experiment, a mixture of gases was allowed to circulate over electric discharge from a tungsten electrode.
(iii) A small flask was kept boiling and the steam emanating from it was made to mix with the mixture of gases (ammonia, methane, and hydrogen) in the large chamber that was connected to the boiling water. The steam condensed to form water which ran down the 'U' tube.
(iv) The experiment was conducted continuously for a week and the liquid was analyzed. Glycine, alanine, beta-alanine, and aspartic A acid were identified. Thus Miller's experiments highlighted the possibility of abiogenetic synthesis of a large amount of variety of organic compounds in nature from a mixture of sample gases in which the only source of carbon was methane. Later in similar experiments, formation of all types of amino acids, and nitrogen bases were noticed.

Similarities found in Neanderthal man and Homo sapiens.
(i) They knew to protect their bodies. Neanderthal man used animal hides to protect their bodies.
(ii) They knew the use of fire.
(iii) They buried their dead.

Fossilization is the process by which plant and animal remains are preserved in sedimentary rocks. They fall under three main categories.
(i) Actual remains
The original hard parts such as bones, teeth or shells are preserved as such in the earth's atmosphere, which is not the common method of fozzilization.
2. When marine animals die, their hard parts such as bones, shells etc. are covered with sediments and are protected from further deterioration.
3. Such parts get preserved in vast ocean, the salinity in them prevents decay.
4. The sediments become hardened to form definite layers (or) strata.
5. For example wooly mammoth that lived 22 thousand years ago were preserved in the frozen coast of Siberia as such, several human beings and animals living in the animals living in the ancient city of pompeii were preserved infact by volcanic ash which gushed out from Mount Vesuvivs.
(ii) Petrifaction
1. After death of animals their original portion of their body may be replaced molecule for molecule by minerals and the original substance being lost through disintegration.
2. This method of fozzilation is called pertifaction.
3. The principle minerals involved in this type fozzilation are iron, pyrites, silica, calcium, carbonate, and bicarbonates of calcium and magnesium.
(iii) Natural moulds and casts
1. Even after disintegration, the body of an animal might leave indelible impression on the soft mud which later becomes hardened into stones. Such impressions are called moulds.
2. The cavities of the moulds may get filled up by hard minerals and get fozzillized, which are called casts.
3. Hardened faecal. matter termed as coprolites occur as tiny pellets.
4. Analysis of the coprolites enable us to understand the nature of diet, the pre historic animals thrived on.

(i) Microevolution refers to the changes in allele frequencies within a population.
(ii) Allele frequencies in a population may change due to four fundamental forces of evolution such as natural selection, genetic drift, mutation and gene flow.

The term evolution is used to describe heritable changes in one or more characteristics of a population of species from one generation to the other.

(i) The earliest fossils of the prehistoric man like Ramapithecus lived some 14mya. They were hairy and walked like gorillas and chimpanzees.
(ii) They had a brain capacity of 1300cc.
(iii) They lived on tough food consisting of seeds and savannah grasses and had well developed grains and heavy molars.
(iv) Australopithecus had a brain capacity of 461cc, teeth consisted of small canines and large molars. Good are softer foods consisting of grass, leaves and fruits.

Ramapithecus\(\rightarrow \) Austrolopithecus \(\rightarrow \) Homo habilis \(\rightarrow \)  Homo sapiens

Lamarcks 'theory of acquired character's was disproved by August Weismann who conducted experiments on mice for twenty generations by cutting their tails and Weismann proved that change in the somatoplasm will not be transferred to the next generation but changes in the germplasm will be inherited.

1. Hardy -Weinberg principle states that the  allele frequencies in a population are stable  and remain constant from generation to  generation it is called genetic equilibrium.
2. The sum total of all the allele frequencies is one and is represented by the equation.
p² + 2pq + q² = 1
Any change of frequency of alleles in a population in interpreted as resulting in evolution.
The factors that affect the genetic equilibrium are
1. Gene flow/migration
2. Genetic drift
3. Mutation
4. Genetic recombination

(d) Both A & B are false

(c) A is correct R is false

(c) Use and disuse
Reason: It is linked to Lamarckism whereas the others are linked to Darwinism.

(d) Oenothera
Reason: It is not linked to adaptive radiation whereas the others show adaptive radiation.