(i) Arachaeopteryx.
(ii) It had wings with feathers like a bird.
(iii) It had conical teeth like a reptile.

Yes. When there is a change in the environment, the animals respond to the change. They develop adaptive structures. The characters developed by the animals during their life time, in response to the environmental changes are called acquired characters.
(i) Leo lived in the mountain region and it was wild. It developed hunting skills for survival and this made his legs and body strong. So the muscled physical body, strong legs and hunting skills were the acquired characters inherited by Leo.
(ii) According to Lamarck, the. acquired characters are transmitted to the offspring by the process of inheritance.

Use and disuse theory
(i) Lamarck's Use and Disuse theory states that if an organ is used constantly, the organ develops well and gets strengthened.
(ii) When an organ is not used for a long time, it gradually degenerates.
(iii) The ancestors of Giraffe were provided with short neck and short forelimbs.
(iv) Due to shortage of grass, they were forced to feed on leaves from trees. The continuous stretching of their neck and forelimbs resulted in the development of long neck and long forelimbs which is an example for constant use of an organ.
(v) The degenerated wing of Kiwi is an example for organ of disuse.

The comparative study of Morphology and Anatomy of animals, reveal that they possess common set of characteristics.
(a) Homologous organs:
(i) The homologous organs are those which have inherited from common ancestors with similar developmental pattern in embryos.
(ii) E.g: The fore limbs of mammals are homologous structures. A Human hand, a front leg of a Cat, flipper of a Whale and a Bat's wing look dissimilar and adapted for different functions. Their mode of development and basic structure of bone are similar.
(b) Analogous organs:
(i) The analogous organs look similar and perform similar functions but they have different origin and developmental pattern.
(ii) The function of the wings of a Bat, the wings of a bird and wings of an insect are similar, but their basic structures are different.
(c) Vestigial organs:
(i) The degenerated and non-functional organs of animals are called Vestigial organs. The same organs are found to be well-developed and functional, in some of the related forms.
(ii) E.g: Some of the Vestigial organs in man are Vermiform appendix, Nictitating membrane, Caudal Vertebra, Coccyx etc.
(d) Atavism:
(i) The reappearance of ancestral characters in some individuals is called Atavism.
(ii) E.g: Presence of rudimentary tail in new born babies, presence of thick hair on the Human body.

(i) Archaeopteryx is considered to be a connecting link between reptiles and birds.
(ii) It had wings with feathers like a bird. It has long tail, clawed digits and conical teeth like a reptile.

Natural selection is a driving force for evolution.
Over production:
(i) Living beings have the ability to reproduce more individuals and form their own progeny. 
(ii) They have the capacity to multiply in a geometrical manner.
(iii) This will increase reproductive potential leading to over production.
Struggle for existence:
(i) Due to over production, a geometric ratio of increase in population occurs.
(ii) The space to live and food available for the organisms remain same
(iii) This creates an intense competition among the organisms for food and space leading to struggle.
The struggle for existence are of three types:
(i) Intraspecific struggle: Competition among the individuals of same species.
(ii) Interspecific struggle: Competition between the organisms of different species living together.
(iii) Environmental struggle: Natural conditions like extreme heat or cold, drought and floods can affect the existence of organisms.
Variations:
(i) The occurrence of variation is a characteristic feature of all plants and animals.
(ii) Small variations are important for evolution.
(iii) According to Darwin favourable variations are useful to the organism and unfavourable variations are harmful or useless to the organism.
Survival of the fittest or Natural selection:
(i) During the struggle for existence, the organisms which can overcome the challenging situation, survive and adapt to the surrounding environment.
(ii) Organisms which are unable to face the challenges, are unfit to survive and disappear.
(iii) The process of selection of organisms with favourable variation is called as natural selection.
Origin of species
(i) According to Darwin, new species originates by the gradual accumulation of favourable variations for a number of generations.

(i) Octopus, cockroach and frog all have eyes.
(ii) Octopus-belongs to mollusc which have simple eye without lens.
(iii) Cockroach are invertebrate have compound eyes.
(iv) Frog which is vertebrate, have highly specialised lens.
(v) However, all of them perform the same function that is vision.
(vi) Thus a common evolutionary origin can be established on the basis of eye.

(i) Fossils are remains or impressions of organisms that lived in the remote past.
(ii) Fossil provide the evidence that the present animal have originated from previously existing ones through the process of continuous evolution.

Yes, he is correct.
Reason: The function of the wings of a crow (the wings of a bird) and wings of an insect are similar, but the basic structure is different.