Punjab Board Class 11 Biology — Flashcards for Quick Revision

A: Biodiversity refers to the number and types of organisms present on Earth. The number of species that are known and described ranges between 1.7 to 1.8 million. This represents all the different kinds

A: Standardized naming is necessary because organisms are known by different local names in different regions and countries. For example, the same plant might be called 'Aloo' in Hindi, 'Batata' in Marat

A: The two main processes are: (1) Identification - recognizing and determining what organism you are looking at by carefully observing its characteristics and comparing them with known descriptions. (2)

A: The Two Kingdom Classification (Plantae and Animalia) could not accommodate organisms that did not fit clearly into either category. It also failed to distinguish between eukaryotes and prokaryotes, u

A: Kingdom Monera consists solely of bacteria, which are prokaryotic organisms lacking a membrane-bound nucleus. Key characteristics include: cell walls made of polysaccharides and amino acids (not cellu

A: Archaeabacteria are specialized bacteria that survive in extreme harsh habitats such as highly salty areas (halophiles), hot springs (thermoacidophiles), and marshy areas (methanogens). Their uniquene

A: Algae are chlorophyll-bearing, simple, thalloid, autotrophic organisms that are largely aquatic. Key characteristics include: (1) Can be unicellular, colonial, or filamentous in form; (2) Contain well

A: Chlorophyceae (Green algae): Contain chlorophyll a and b, giving them a grass-green color; mostly freshwater and some brackish/marine habitats; store food as starch. Phaeophyceae (Brown algae): Contai

A: Three types of sexual reproduction in algae based on gamete characteristics: (1) Isogamous - fusion of two similar-sized flagellated or non-flagellated gametes, e.g., Ulothrix and Spirogyra. Both game