NCERT LINE BY LINE – BSI SIR FAN CLUB

NCERT – Plant Evolution Picture

free, NCERT LINE BY LINE / Prof. Siddharth Sanghvi

The Evolutionary Saga of Plants 🌿 The Evolutionary Saga of Plants Plants have shaped Earth’s history, transforming its atmosphere, biodiversity, and ecosystems. Their journey from **simple aquatic algae** to **complex flowering plants** is a story of adaptation, survival, and dominance. 🌍 Paleozoic Era: The Dawn of Land Plants (541–252 MYA) 🟢 Silurian Period (443–419 MYA): […]

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Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. The female gametophytes in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos take place within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution. Assertion – In gymnosperms, the male and female gametophytes depend on the sporophyte.

free, NCERT LINE BY LINE, Plant Kingdom / Prof. Siddharth Sanghvi

Assertion & Reason: Gametophyte Dependence in Gymnosperms Assertion (A): In gymnosperms, the male and female gametophytes depend on the sporophyte. Reason (R): Gymnosperms are universally heterosporous. Explanation: 1. What is Needed for an Independent Gametophyte? For a gametophyte to be independent, it should: Be able to grow outside the sporophyte’s body. Have its own nutrition

Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous. The megaspores and microspores germinate and give rise to female and male gametophytes, respectively. The female gametophytes in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos take place within the female gametophytes. This event is a precursor to the seed habit considered an important step in evolution. Assertion – In gymnosperms, the male and female gametophytes depend on the sporophyte. Read More »

NCERT-Continued self pollination lead to inbreeding depression

NCERT LINE BY LINE, Sexual Reproduction in flowering Plants / Prof. Siddharth Sanghvi

Inbreeding Depression in Plants Inbreeding Depression in Plants Inbreeding depression refers to the reduced biological fitness in a population due to increased homozygosity, which results in the expression of deleterious recessive alleles. This leads to reduced vigor, fertility, and adaptability. How Self-Pollination Leads to Inbreeding Depression Self-pollination increases homozygosity over generations. Recessive alleles, normally hidden

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NCERT-Convergent Evolution of Mammal—Diagram Explained

Evolution, NCERT LINE BY LINE / Prof. Siddharth Sanghvi

Convergent Evolution of Mammals Convergent Evolution, Divergent Evolution, and Adaptive Radiation Convergent Evolution Convergent evolution occurs when unrelated species evolve similar traits due to similar environmental pressures. This phenomenon is evident in placental mammals and Australian marsupials. Divergent Evolution Divergent evolution occurs when a common ancestor evolves into distinct species due to different environmental conditions.

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Double fertilization is an event unique to flowering plants.

NCERT LINE BY LINE, Sexual Reproduction in flowering Plants / Prof. Siddharth Sanghvi

Double Fertilization – Assertion & Reason Assertion & Reason – Double Fertilization Assertion (A): Double fertilization is an event unique to flowering plants. Reason (R): Since two types of fusions, syngamy and triple fusion, take place in an embryo sac, the phenomenon is termed double fertilization. Choose the correct answer: (1) Both Assertion & Reason

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Special Integuments – Aril and Caruncle or Strophiole

NCERT LINE BY LINE, Sexual Reproduction in flowering Plants / Prof. Siddharth Sanghvi

Caruncle and Aril: Structures and Significance Feature Caruncle Aril Definition A spongy, bilobed outgrowth of the outer integument or testa of the seed. Found in castor seed (Ricinus communis), soft and fleshy. A post-fertilization fleshy, collar-like outgrowth of the funicle at the micropylar end in the pericarp. Functions Water Absorption: Aids in imbibition, helping germination.

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NCERT- Evolution Diagram Dinosaur -A family tree of dinosaurs and their living modern day counterpart organisms like crocodiles and birds

Evolution, NCERT LINE BY LINE / Prof. Siddharth Sanghvi

Evolutionary Lineage of Archosauria Category Description Examples Archosauria (Common Ancestor) Archosaurs, a group of reptiles from the early Triassic (~250 million years ago), are the common ancestor of crocodilians, pterosaurs, and dinosaurs. None Branches Crocodylomorpha (Crocodilians) Crocodiles and their relatives diverged early (~230 million years ago). Evolved independently but retained traits of their ancient archosaur

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Cytoplasmic Inheritance by Sidd Sir – Male sterility in maize, variegated leaves in Mirabilis jalapa.

NCERT LINE BY LINE, PRINCIPLES OF INHERITANCE AND VARIATION / Prof. Siddharth Sanghvi

Comparison of Cytoplasmic and Nuclear Inheritance Feature Cytoplasmic Inheritance Nuclear Inheritance Definition Transmission of traits via genes located in organelles like mitochondria or chloroplasts. Transmission of traits via genes in the nuclear chromosomes. Location of Genes Found in mitochondrial or chloroplast DNA (extranuclear). Found in chromosomal DNA inside the nucleus. Inheritance Pattern Maternal (zygote inherits

Cytoplasmic Inheritance by Sidd Sir – Male sterility in maize, variegated leaves in Mirabilis jalapa. Read More »

MOLECULAR BASIS OF INHERITANCE -1- Over the next hundred years, the nature of the putative genetic material was investigated culminating in the realisation that DNA – deoxyribonucleic acid – is the genetic material, at least for the majority of organisms.

Molecular Basis of Inheritance, NCERT LINE BY LINE / Prof. Siddharth Sanghvi

Master Table: Molecular Basis of Inheritance Topic Explanation Key Details MCQ Inheritance Patterns Factors regulating inheritance patterns were unclear in Mendel’s time but are now linked to genetic material (DNA/RNA). – DNA is the genetic material in most organisms.– RNA functions as a genetic material in some viruses and a messenger in others. Q: What

MOLECULAR BASIS OF INHERITANCE -1- Over the next hundred years, the nature of the putative genetic material was investigated culminating in the realisation that DNA – deoxyribonucleic acid – is the genetic material, at least for the majority of organisms. Read More »

Difference Between Progeny and Offspring in Genetics

NCERT LINE BY LINE, PRINCIPLES OF INHERITANCE AND VARIATION / Prof. Siddharth Sanghvi

Difference Between Progeny and Offspring in Genetics Aspect Progeny Offspring Definition Progeny refers to the descendants or the next generation of an organism, often used in a broader scientific or formal context. Offspring refers to the immediate biological descendants of an organism, typically used in a general or informal context. Context More commonly used in

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