Science M.C.Q

Wings of an insect and forelimbs of a bird are analogous organs, as they have different structures but perform the same function of flying.

Homologous organs are those organs that have originated from the same basic structure but perform different functions.
The wings of birds and forelimbs of the horse originated from a similar structure but use them differently.
Thus, these structures are homologous structures.

Analogous organs are that which are different in origin but similar in function.

Homologous structures means that they had come from a common ancestor, e.g., hind legs of pig, duck and kangaroo.

The science of heredity is known as genetics.

The theory of evolution of species by natural selection was given by Charles Darwin in his book The Origin of Species.

A Large number of human fossils have been discovered from Africa.
This led to the "Out of Africa hypothesis" according to which modern humans evolved only in Africa and then traveled to Asia, Europe, and other places to replace the indigenous populations.
Most probably, Homo erectus was the first hominid to move out of Africa, and colonize Asia, Europe, and other parts of the earth.

Butterfly and bat wings cannot be considered homologous organs as they have different basic designs.

The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation.

Heredity can be defined as the transmission of various genetic characteristics from the parents to their offspring.
These characteristics include the colour of the eyes, the hairstyle, the shape of the face, nose, etc.
The similarity between parents’ physical features and their children’s physical features is marked by heredity inherent traits.

Homologous structures have a same basic structural design but different function. Here radish and carrot are homologous structures.

Snub nose is an inherited trait, and can be can be passed on to the progeny.

Wings of birds and wings of bat, Wings of a parrot and wings of a butterfly; these are analogous organs as they have different structures but perform same function.

These are sex chromosomes determining the gender of the offspring.

The organs that perform different functions but have the same basic structure are known as homologous organs.
For example : forelimbs of humans and lizards are homologous.

imilar species occupying the same niche will have similar requirements, hence, there will be more competition.
If organisms have different requirements or they occupy different niches, then competition will be less.

All variations in a species do not have an equal chance of survival. Variations may either be beneficial or harmful to the species.

Earliest members of the human species came from Africa.

Scarred chin is an acquired trait, which an individual gets due to an accident. It cannot be passed on to the progeny.

In evolutionary terms, we have more in common with a chimpanzee because both human beings and chimpanzees had a common ancestor, long time ago.

Starting from a common ancestor, homologues show gradual changes, retaining the overall basic structure and not deviating drastically.

Seven characters found in garden pea plants were selected by Mendel for his experiment.
They were seed shape, seed colour, flower colour, pod shape, pod colour, flower position, and stem height.
For the experiments, Mendel selected a set of two contrasting traits for each of these characters.

According to scientists, aves have evolved from reptiles.

Homologous organs are those that have similar structures and share common ancestors but have different functions e.g., the wings of a bat for flight, the lateral fin of a whale for swimming, and the human arm to hold or lift any object.

The weight reduction due to starvation is environmentally determined factor.

Homologous structures are similar in origin but perform different functions. Carrot and radish are underground roots. So, they represent the correct homologous structures.