Hello james,

The two key concepts of Darwin’s theory of evolution are:

1. Branching Descent

2. Natural Selection

Branching Descent

It is the process in which new species originate from a single ancestor. They became adapted to the new environment through reproductive isolation. For eg., Darwin’s finches which evolved from a single grain eater species.

Natural Selection

In this process, the variations in an individual facilitate better survival of species. They reproduce in large numbers. These variations are passed on to successive generations which help them to survive in the changing environmental conditions. For eg., few giraffes have long necks while others have short necks. If the low-lying shrubs are eliminated for some reason, the giraffes with short necks would be replaced by giraffes with long necks.

HOPE THIS WILL HELP YOU

GOOD LUCK

Hello Rajeev!

Camouflage refers to the term disguise. It is a natural phenomenon used by plants and animals to disguise themselves as per their environment. They mimic according to their surroundings to avoid detection. Thus it increases the chance of survival by hiding it from predators.

Camouflage is the natural defence mechanism developed in the prey. During this phenomenon, animals change their skin colour or disguise themselves as per their surrounding colour so that they cannot be detected by other predators. Certain predators also use this mechanism for hunting. For instance, Stone Flounder, a flatfish, is one such predator which lays on the ocean floor in search of its prey.

Following are a few examples of camouflage animals:

• Owl
• Uroplatus Geckos
• Toads
• Seahorse
• Frog
• Spider
• Stick insect
• Snow Leopard

Hope this was helpful!

Hello,

To get an admission in PHD you need to score 630 marks in GATE score and you need to have 60% of marks in your Degree.

Hope this helps you.

Option number 3 that is Tuatara -> Lizard -> Snake -> Crocodile is the correct answer. Tuataras are reptiles endemic to New Zealand and Lizards were evolved from Tuatara only. The snakes are close relatives of the lizards. However, they lack external ear openings and movable eyelids.

Thank you.

Hi Ishika

Answer is 1. Erectus ->Homo -> Primate ->chordate - >Animalia

Hope it helps you

Best of Luck!

Statement number 2 is the correct one. That is cryptic camouflage is seen in Biston Betularia.

It is a temperate species of moths who fly at night. Biston Betularia is also called as the peppered moth. As an example of natural selection, peppered moth's example is oftenly used.

Best wishes. Thank you.

Homologous and vestigial organs that is option number 1 is the correct answer.

Homologous organs have a common origin and are built on the same basic fundamental principle but they have variant appearance and perform different functions as well. At the same time, Vestigial organs had important functions in the animals' ancestors and basically dont have much to do now.

Therefore option number 1 is correct.

Thank you.

Hello,

Protobiotics are live micro organisms promoted with claim that they provide help benefits in the time of need. In evolutionary system protobiotics are consume generally safe in the system.

But some rare cases some unwanted side effectes are also noticed regarding protobiotics.

Hope it will be helpful for you.

Thank you.

Hello Isshika,

The plica semilunaris is a fold of the conjunctiva at the inner corner of the human eye.

The similarity to the nictitating membrane, or third eyelid, of other animals led to the conjecture that it might be the vestige of such a structure, which is still a part of the eye in some primates, including gorillas.

However in chimpanzees, one of the human species’ closest relatives, the plica semilunaris appears to be vestigial.

The purpose of the nictitating membrane in many animals is that of protection. For instance,  it helps in keeping the eye clean and moist and concealing the iris from predators. The membrane, in certain species, is sufficiently transparent to enable vision when underground or underwater.

Though the reason for the loss of a nictitating membrane in humans in rather ambiguous, changes in our habitat and the physiology of the eye may have put the tissue out unnecessary.

Hope this helps you. We wish you the best for your future endeavours!

Regards