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प्रश्न
Write short notes based upon the information known to you.
Embryology
उत्तर
Embryology: Embryology is the study of the formation and development of embryo and foetus. Embryology is used as one of the evidences of evolution. Comparative study of embryos in vertebrates shows that there is lot of similarity in them at the initial stages whereas this similarity decreases gradually. This similarity in the development of embryos represents common origin of organisms.
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संबंधित प्रश्न
What are vestigial organs?
Give two examples of vestigial organs in human beings and plants.
(a) Select the homologous structures from the combinations given below:
(i) Forelimbs of whales and bats
(ii) Tuber of potato and sweet potato
(iii) Eyes of octopus and mammals
(iv) Thorns of Bougainvillea and tendrils of Cucurbita
(b) State the kind of evolution they represent.
(a) Select the analogous structures from the combination given below:
(i) Forelimbs of whales and bats
(ii) Eyes of octopus and mammals
(iii) Tuber of sweet potato and potato
(iv) Tuber of Bougainvillea and tendrils of Cucurbita
(b) State the kind of evolution they represent
Differentiate between analogy and homology giving one example each of plant and animal respectively.
Four students A, B, C and D reported the following set of organs to be homologous. Who is correct ?
(A) Wings of a bat and a butterfly
(B) Wings of a pigeon and a bat
(C) Wings of a pigeon and a butterfly
(D) Forelimbs of cow, a duck and a lizard
Which one of the following pairs of vegetables is an example of homologous structures?
(A) Potato and sweet potato
(B) Carrot and radish
(C) Carrot and tomato
(D) Tomato and radish
Four students P, Q, R and S differently reported the following set of organs to be analogous :
P. Forelimb of a frog and forelimb of a lizard
Q. Forelimb of a bird and forelimb of a human
R. Wings of a parrot and wings of a butterfly
S. Wings of a bird and wings of a bat
The two students who have reported correctly are :
(A) P and Q
(B) Q and R
(C) R and S
(D) P and S
An example of homologous organs is
Explain the evolution of giraffe's neck according to Lamarck's theory of evolution.
How do homologous organs help in providing evidence for organic evolution?
The organs which perform different functions but have the same basic structure are known as :
(a) homologous organs
(b) analogous organs
(c) homolytic organs
(d) analytic organs
The organs which perform similar functions but have different basic structure are called :
(a) asymmetric organs
(b) analogous organs
(c) homologous organs
(d) homophonic organs
Some dinosaurs had feathers although they could not fly birds have feathers that help them to fly. In the context of evolution, this means that ______
There are five animals A, B, C, D and E. The animal A uses its modified forelimbs for flying. The animal B uses its forelimbs for running whereas the animal C uses its forelimbs for grasping. The animal D can live on land as well as in water and uses its forelimbs to prop up the front end of its body when at rest. The animal E which respires by using spiracles and tracheae uses wings for flying but its wings are analogous to the modified forelimbs of animal A.
(a) What could the animals A, B, C, D and E be?
(b) Why are the forelimbs of animals A, B, C, D called homologous organs?
(c) What does the existence of homologous organs in animals A, B, C and D tell us about their ancestors ?
(d) Why are the modified forelimbs of animal A and the wings of animal E called analogous organs?
(e) State whether animals A and E have a common ancestor or not.
Read the following statement and justify same in your own words with the help of suitable example.
There is evidences of fatal science among chordates.
Vestigial organ ______ present in human body is proof of evolution.
“Appearance of melanised moths post-industrialisation in England is a classic example of evolution by natural selection.” Explain.
With the help of diagrams, describe emasculation and bagging.
Name the parts shown in the diagram.
Human jaw
Observe the given images and answer the following questions.
- Which evolutionary evidence does it indicate?
- What does it prove?
- State another example of evolutionary evidence.
Which evidence of evolution is shown in the given picture? Explain the importance of this evidence.
Explain any five types of evidence that support the theory of evolution.
The degenerated and non-functional organs found in an organism are called ______.
Why do all the gametes formed in human females have an X chromosome?
Basic principles of embryonic development were pronounced by:
Which is not a vestigial organ in a man?
Which of the following is used as an atmospheric pollution indicator?
Animal husbandry and plant breeding programmes are the examples of ______.
Complete the following chart:
Write down the difference between homologous and analogous organs.
Define the term:
Homologous organs
Industrial melanism was highlighted by ______.
