Answer: Option B. -> Both A and R are correct and R does not explain A
:
B
The earliest primates are assumed to have evolved from the then common mammals like shrews. Some of the early primates evolved into monkeys. Some of these monkeys, further, became the common modern monkeys, while the relatives of monkeys which diverged from the common ancestor, evolved into primitive apes. A group of apes split into two groups - one evolved into the modern gorillas, and the other into chimpanzee - human ancestor. Then from this group, modern chimpanzees and humans parted ways and evolved into their modern forms. During the course of all this evolution, the forelimbs of apes got modified, resulting in bipedalism, which freed the forelimbs for more actions. However, this is not the reason for the evolution of apes into humans.

Answer: Option C. -> Mesozoic
:
C
The total span of Earth’s evolution or geological time is basically divided into six eras -Azoic, archaeozoic, proterozoic, palaeozoic, mesozoic and cenozoic.Mesozoic era is known as "the golden age of reptiles" as it was marked with the emergence and evolution of a variety of reptilian species. This era witnessed the dominance of dinosaurs and toothed birds like Archaeopteryx, evolution of marsupials from prototheria etc. Cenozoic era is the era in which we are currently living, and it is called the "age of mammals".

Answer: Option C. -> Forelimbs of man and wings of bat
:
C
The forelimbs of man and bat are anatomically similar in that they have similar bones including the humerus, radius, ulna, carpals, metacarpals and phalanges. However, these structures have been collectively modified into forelimbs in man and wings in bat, performing different functions. The human forelimbs are meant to perform different kinds of physical activities, while the bat wings are used for flight. The human eye and squid eye, the gills of fish and lungs of man, and the stings of bee and scorpion are all examples of analogous organs, which are structurally different and functionally similar.

Answer: Option C. -> p-i, q-iii, r-iv, s-ii
:
C
The major forces that control the process of evolution are gene flow, genetic drift, mutation pressure and natural selection.
Gene flow is the transfer of alleles or genes from one population to another.
Genetic drift refers to a change in the frequency of alleles or genes in a population, due tochance events. Bottleneck effect and founder effect are two phenomena that increase the impact of genetic drift.
Bottleneck effect is the phenomenon by which natural disasters bring about a sharp lowering of a population’s gene pool.
Founder effect is a phenomenon by which a few members of the original population colonise a new location away from the old.

Answer: Option A. -> Methane : Ammonia : Hydrogen
:
A
Miller introduced methane, ammonia and hydrogen in the ratio 2:1:2 in the high energy chambers of his experimental setup. With this ratio of gases, he was able to synthesise innumerous organic molecules including amino acids.

Answer: Option B. -> i - 0.4, ii - 0. 16, iii - 0.48
:
B
According to Hardy-Weinberg equation,
$p^2+2pq+q^2=1andp+q=1$
Assuming that ‘p’ is the frequency of occurrence of the dominant allele ‘A’ and ‘q’ is the frequency of occurrence of the recessive allele ‘a’, we could say that the frequency of occurrence of the genotype aa=36%
$\Rightarrow q\times q=36$
$\Rightarrow q^2=0.36$
$\Rightarrow q=\sqrt{0.36}$
$\Rightarrow q=0.6$
Therefore the frequency of recessive allele a = 0.6
Applying the equation p+q = 1
$\Rightarrow p=1-q$
$\Rightarrow p=1-0.6=0.4$
Therefore, the frequency of dominant allele A = 0.4
The frequency of the homozygous genotype $\left(AA\right)=p^2$
$p^2=(0.4\times 0.4)=0.16$
The frequency of the heterozygous genotype (Aa)=2pq
$2pq=2\times 0.4\times 0.6=0.48$

Answer: Option A. -> True
:
A
Neo - lamarckism, through relevant experiments and a new branch of genetics known as epigenetics, supports Lamarck's concept of inheritance of acquired characters. In such cases, environmental changes affecting somatic cells may get inherited through the germ cells. In some cases, germ cells may also be directly affected by environmental changes. Therefore germ cells formed from somatic cells can inherit changes in those somatic cells, due to influential environmental changes.

Answer: Option A. -> True
:
A
The theory of spontaneous generation advocated by scientists including Aristotle, Plato and Van Helmont explains that life originates everyday, all the time, from inanimate objects such as mud, dirt, dust, organic matter and many other nonliving sources.

Answer: Option B. ->  Archaeopteryx
:
B
Missing links or transitional species are those intermediate species in the line of evolution, that exhibit characteristics that were found in their immediate ancestral and descendant groups. These links thus, fill up the so-called gaps in the evolutionary record of species. For example, Archaeopteryx is a link, that was missing for a long time in the evolutionary record between reptiles and birds.Itis today, known as a transitional species between the two groups - reptiles and birds. Archaeopteryx had jaws with teeth and a long bony tail like the dinosaurs, broad wings and feathers like birds, and skeletal features of both.

Answer: Option B. -> Miocene
:
B
Australopithecus afarensishas been known to be a long-lived early "ape man" found in South Africa. It is documented to have originated inthe final epoch of the Tertiary period - the Miocene epoch. The Miocene epoch existed about 22 - 5 mya, and witnessed the evolutionand emergence of man-like apes. The end of the Tertiary period marks the onset of the Quaternary period. This period is divided into two epochs - Pliocene and Holocene. The Pliocene epoch saw many important events in the evolutionary history of the world. Itwitnessed the emergence of herbs and emergence of the genus Homo.The Holocene epoch is the one that continues even today. This epoch is characterised by supremacy of manand the evolution of monocots along with dominance of herbs.