NCERT Graphs PDF

# Activation Energy - **Figure 9.6 Concept of activation energy** - This figure shows the potential energy of a reaction with and without an enzyme. - The activation energy is the minimum amount of energy required for a reaction to occur. - Enzymes lower the activation energy of a reac...

# Activation Energy - **Figure 9.6 Concept of activation energy** - This figure shows the potential energy of a reaction with and without an enzyme. - The activation energy is the minimum amount of energy required for a reaction to occur. - Enzymes lower the activation energy of a reaction, making it easier for the reaction to occur. # Effects of pH, Temperature and Substrate Concentration on Enzyme Activity - **Figure 9.7 Effect of change in (a) pH (b) Temperature and (c) Concentration of substrate on enzyme activity** - The figure shows the effect of different factors on enzyme activity. - **(a) pH** - Enzyme activity is highest at a specific pH, called the optimum pH. - Enzyme activity decreases as the pH moves away from the optimum pH. - **(b) Temperature** - Enzyme activity increases with temperature up to a certain point called the optimum temperature. - Enzyme activity decreases at higher temperatures because the enzyme denatures. - **(c) Concentration of substrate** - Enzyme activity increases with substrate concentration up to a certain point. - Once all the active sites on the enzyme molecules are filled, the rate of reaction reaches maximum velocity, Vmax. - Km is the substrate concentration at half the maximum velocity (Vmax/2). # Photosynthesis - **Figure 9.8 Absorption spectra of chlorophyll a, chlorophyll b, and carotenoids** - This figure shows the absorption spectra of chlorophyll a, chlorophyll b, and carotenoids. - Chlorophyll a and b absorb light mainly in the blue and red regions of the visible spectrum. - Carotenoids absorb light in the blue and green regions and are responsible for the yellow, orange and red colors of leaves during autumn. - **(b) Action spectrum of photosynthesis** - Action spectrum of photosynthesis shows the rate of photosynthesis at different wavelengths of light. - It is similar to the absorption spectra of chlorophyll a and b. - The highest rate of photosynthesis occurs in the blue and red regions of the visible spectrum. - **(c) Relationship between the action spectrum and the absorption spectrum of chlorophyll a and b.** - The figure shows that the action spectrum of photosynthesis closely matches the absorption spectrum of chlorophyll a and b. - The rate of photosynthesis is highest at those wavelengths where chlorophyll a and b absorb light most strongly. - **Figure 9.9 Effect of light intensity on the rate of photosynthesis** - This figure shows the effect of light intensity on the rate of photosynthesis. - At low light intensity, the rate of photosynthesis increases linearly with increasing light intensity (i.e. the rate of photosynthesis is directly proportional to the light intensity). - At high light intensity, the rate of photosynthesis levels off, indicating that the process is saturated. - This is because the rate of photosynthesis is limited by other factors, such as the availability of CO2, temperature, or the amount of chlorophyll. # Growth - **Figure 15.5 Constant linear growth,** a plot of length L against time t - This figure shows a plant growing at a constant rate. - The height of the plant increases linearly with time. - **Figure 15.6 An idealized sigmoid growth curve typical of cells in culture, and many higher plants and plant organs** - This figure shows the typical growth curve of a plant or animal. - The curve has four phases: - *Lag phase*: The initial phase when the growth is slow as the cell starts to adapt to the new environment. - *Exponential phase*: This is where the growth rate accelerates exponentially. - *Stationary phase*: This is when the growth rate slows down and the population size remains constant. This is because the resources may start to become limited. - *Decline phase*: The population size declines because of less nutrients or less favorable conditions. # Oxygen Dissociation Curve - **Figure 17.5 Oxygen dissociation curve** - Shows the relationship between partial pressure of oxygen and the percentage saturation of haemoglobin with oxygen. - At low partial pressure of oxygen, haemoglobin binds oxygen easily and quickly becomes saturated. - As the partial pressure of oxygen increases, the rate of binding decreases until it reaches maximum saturation. # ECG - **Figure 18.3 Diagrammatic presentation of a standard ECG** - Represents a standard electrocardiogram (ECG) trace. - The ECG records the electrical activity of the heart. - The different waves in the ECG represent the different phases of the cardiac cycle: - **P wave:** Represents the depolarization of the atria. - **QRS complex:** Represents the depolarization of the ventricles. - **T wave:** Represents the repolarization of the ventricles. # Natural Selection - **Figure 18.4 Effect of natural selection on variation in a population** - **(a)** Shows the effect of stabilizing selection on a population. - In stabilizing selection, the extreme forms of the trait are eliminated and the intermediate form is favored. This results in a narrow and taller peak of the graph. - **(b)** Shows the effect of directional selection on a population. - In directional selection, one of the extreme forms of the trait is favored and the population shifts towards that extreme. This results in the peak of the graph shifting in one direction. - **(c)** Shows the effect of disruptive selection on a population. - In disruptive selection, both extreme forms of the trait are favored and the intermediate form is eliminated. This results in two separate peaks in the graph. # Biomes - **Figure 19.1 Major biomes of India** - The figure shows the major biomes of India, including tropical rainforests, deciduous forests, grasslands, and deserts. - The location of each biome is determined by factors such as climate, rainfall, temperature, and altitude. - **Figure 19.8 Distribution of major biomes of the world** - The distribution of the major biomes on the world map. - This demonstrates the influence of latitude and annual precipitation on the biomes. # Organismic Response - **Figure 13.3 Diagrammatic representation of organismic response.** - This figure shows the different ways organisms respond to changes in their environment: - **Conformers:** Organisms whose internal environment changes with the external environment. - **Regulators:** Organisms that maintain a stable internal environment, despite changes in the external environment. - **Partial regulators:** Organisms that can regulate their internal environment over a certain range of environmental conditions. # Population Pyramids - **Figure 13.4 Representation of age pyramids for human population** - This figure shows different age pyramids for human populations. - **Expanding pyramid:** This type of pyramid has a wide base and a narrow top. The pre-reproductive population is larger than the reproductive population, indicating a growing population. - **Stable pyramid:** This type of pyramid has a more even distribution of population across ages. - **Declining pyramid:** This type of pyramid has a narrow base and a wider top, indicating a declining population. # Ecological Pyramids - **Figure 14.4 Pyramid of numbers, biomass and energy** - **(a)** **Pyramid of Numbers:** This type of pyramid shows the number of organisms at each trophic level in an ecosystem. - **(b)** **Pyramid of Biomass:** This type of pyramid shows the total biomass of organisms at each trophic level. - **(c)** **Inverted pyramid of biomass:** This type of pyramid shows a reverse pyramid of biomass when the producers have a lower biomass than the consumers. - This is common in aquatic ecosystems where the primary producers (phytoplankton) are small and have a fast turnover rate, leading to low overall biomass. - **(d)** **Pyramid of energy:/ ** This type of pyramid shows the energy flow through each trophic level in an ecosystem. - This pyramid always has a typical shape since the energy flow is always unidirectional and there is a loss of energy at each level during the transfer. # Species Area Relationship - **Figure 15.2 Showing species area relationship.** - This figure shows the relationship between the species richness and the area of a habitat. - The species richness increases with the area of the habitat. - This relationship is represented by a logarithmic equation: S = CA­­­­Z, where S is the number of species, A is the area, and C and Z are constants. # Effect of Sewage Discharge on River Characteristics - **Figure 16.3 Effect of sewage discharge on some important characteristics of a river.** - This figure shows the effect of sewage discharge on a river. - **Dissolved oxygen:** The dissolved oxygen concentration decreases in the river downstream of the sewage discharge point. This is because bacteria decompose the organic matter in the sewage using oxygen, resulting in a decrease in dissolved oxygen. - **Biochemical oxygen demand (BOD):** The BOD increases downstream of the sewage discharge point. This is because the bacteria need to consume oxygen to decompose the organic matter. - **Fish kill and disappearance of clean water organisms:** If the dissolved oxygen levels fall too low, fish and other aquatic organisms may die. - **Reappearance of clean water organisms:** As the sewage is decomposed and the dissolved oxygen levels increase, clean water organisms begin to reappear.