Select the analogous structure (s) from the list given below.

Tubers of sweet potato and potato

Tendrils of Bougainvillea and Cucurbita

Differentiate between analogous and homologous structures.

Feature Analogous structures Homologous structures Developmental origin Analogous structures do not exhibit common developmental origin and common ancestry. These structures have a different structural plan but are evolved to perform similar functions. Homologous structures exhibit common developmental stages in the embryo and have a common ancestry. These structures perform different functions but possess similar anatomy. Feature Analogous structures Homologous structures Type of Evolution Analogous structures among organisms are the result of convergent evolution. Example-flippers of penguins and dolphins. Homologous structures among organisms are the result of divergent evolution. Example- Vertebrates heart and brains.

With the help of an algebraic equation, how did Hardy-Weinberg explain that in a given population the frequency of occurrence of alleles of a gene is supposed to remain the same through generations?

The Hardy-Weinberg principle or law relates allele frequencies to genotype frequencies in a randomly mating population. Now if we take a population with two alleles (A and B) that segregates at a single locus. The frequency of allele A is denoted by p. Frequency of allele B is denoted q. According to Hardy-Weinberg law in the absence of evolutionary forces, the genotype frequencies remain constant and the population is said to be at equilibrium. Thus, making the expression p 2 + 2 p q + q 2 = 1 .

Write the names of the following: A 2 mya primate that lived in East African grasslands.

Scientific evidence shows that the physical and behavioural traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years. Australopithecus is a 2 mya primate that lived in East African grasslands. They lived in East African grasslands about 2 mya (million years ago). They had erect posture, walked on two legs, and were omnivores. Most importantly, they used weapons carved out of stone to hunt. They were cave dwellers and possessed characters of both humans and apes.

Write the names of the following : A 15 mya primate that was ape-like.

The evolution of the human being or the Homo sapiens has initiated about 15 million years ago in history. The gradual changes in the process of evolution took place. Dryopithecus lived 15 mya (million years ago) in Africa and Europe. They were ape-like, hairy, and they walked like gorillas. They had semi-erect posture and large brain size. They were arboreal. Dryopithecus is considered as the direct ancestor of modern day apes.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR BIOLOGY>Chapter 7 - Evolution>CBSE-2019>Q 6

EASY

12th CBSE

IMPORTANT

Earn 100

Mention one example each from plants and animals exhibiting divergent evolution.

Important Questions on Evolution

HARD

12th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR BIOLOGY>Chapter 7 - Evolution>CBSE-2019>Q 7

According to the Darwinian theory of natural selection, the rate of appearance of new forms is linked to the life cycle or the life span of an organism. Explain with the help of an example.