Diversity in Living Organisms

Lamarckism suggests that acquired traits are inherited. A Nobel laureate's intelligence or strength is not an acquired physical trait that would be passed down to offspring in the way Lamarck described, making this a common counter-example.

According to Lamarckism, the ancestors of giraffe had small neck and forelimbs and were like horses. They were residing in places with no surface vegetation, therefore, they had to stretch their neck and forelimbs to take the leaves for food. This led to slight elongation of these parts. Whatever they acquired in one generation was transmitted to the next generation with the result that a race of long necked and long forelimbed giraffes were developed. So, the correct answer is 'Of stretching of necks over many generations by short necked ones'.

Lamarckism was disproved later after putting up the human ear piercing example. Lamarckism which is otherwise called as use and disuse theory advocated the idea that animals acquired characteristics after using certain physical traits constantly.

For the giraffes, the change in the position of the food  (leaves) from near to ground level to higher on the trees, triggered for adaptation to prevent extinction. So, those giraffes that underwent genetic changes/variations and developed long necks were able to obtain food and survive in the changed environmental conditions, while others perished, as this change in the genetic pool was beneficial for the giraffes propagation. It was passed on to next generation and so the modern day giraffe has long necks.

Lamarck explained the long neck of giraffes by suggesting that ancestors stretched their necks to reach higher leaves, and this acquired trait was passed to offspring.

Indian women have getting their ears pierced for thousands of years, but this character does not passed to any offspring, this casts doubt on lamarck's theory of evolution. Later on, in Neo-lamarckism it was explained that only those characters will be inherited which can affect germ cells, while characters that affect somatic cells do not pass to descendants. Thus, the correct answer is 'Indian women have been getting their ears pierced for thousands of years, but not a single baby with pierced ears is born.'

Lamarckism is the theory of acquired characters, it includes :

Lamarck in his use and disuse theory proposed that any body part used vigorously caused it to become stronger and inherited in descendants. Lamarckism was failed to explain the reason behind weak muscles of wrestler’s son. Which was later on explained by August Weismann in his germ plasm theory. The germplasm theory claimed that only those changes would be inherited that affects germplasm (now called DNA) and any change in the body would not affect germplasm, so could not be inherited. Thus, the correct answer is ‘Weak muscles in the son of a wrestler.’

Single-cell protein (SCP) refers to sources of mixed protein extracted from pure or mixed cultures of algae, yeasts, fungi or bacteria (grown on agricultural wastes) used as a substitute for protein-rich foods, in human and animal feeds. Single-cell proteins develop when microbes ferment waste materials including wood, straw, cannery and food-processing wastes, residues from alcohol production, hydrocarbons, or human and animal excreta.

The correct answer is 'Sphenopsida'

The sperm of Selaginella are attracted to the archegonia by chemical substances, specifically malic acid, which is a common chemotactic agent in pteridophytes.

The archegonium of Selaginella is highly reduced and typically contains only one neck canal cell.

Chemotaxis is the movement shown by organism in the direction of the external chemical stimuli. In Selaginella, sperm sense the chemoattractant and orient its swimming towards the archegnonia. Chemotropism is the growth movement shown by organism in the direction of the external chemical stimuli. Chemonasty is the nastic movement shown by organism in response to the external chemical stimuli. Spermatozoa can sense this chemoattractant and orient their swimming direction up the concentration gradient towards the egg cell located in the venter of archegonia

The archegonium which develops from a single superficial cell of prothallus is the archegonial initial found just back of the apical meristem. The archegonia  are sessile and embedded. The archegonial initially divides to give 4+4 cells which make up the neck. The neck has a single neck canal cell.