When the rate of evaporation is low, at night or in the early morning, excess water gets collected in the form of droplets at the special openings of veins of leaves of many herbaceous plants. Such water loss in its liquid phase is called guttation.

The proenzyme pepsinogen; in stomach; gets converted into the active enzyme pepsin; on exposure to hydrochloric acid. Pepsin converts proteins into proteoses and peptones (peptides).

Pepsinogen + HCl → Pepsin + Protein → Proteose + Peptone

Proteins, proteoses and peptones are acted upon by the proteolytic enzymes of pancreatic juices (in small intestine); as given below:

Proteins/Peptonse/Proteoses + Trypsin/Chymotrypsin/Carboxypeptidases → Dipeptides

The enzymes in the intestinal juice act on dipeptides to make amino acids.

Dipeptides + Dipeptidases → Amino acids

The proenzyme pepsinogen; in stomach; gets converted into the active enzyme pepsin; on exposure to hydrochloric acid. Pepsin converts proteins into proteoses and peptones (peptides).

Pepsinogen + HCl → Pepsin + Protein → Proteose + Peptone

Proteins, proteoses and peptones are acted upon by the proteolytic enzymes of pancreatic juices (in small intestine); as given below:

Proteins/Peptonse/Proteoses + Trypsin/Chymotrypsin/Carboxypeptidases → Dipeptides

The enzymes in the intestinal juice act on dipeptides to make amino acids.

Dipeptides + Dipeptidases → Amino acids

  Lichens grow on the surface of rock and extract minerals from them. This creates small crevices at places where a thin layer of soil builds up.

• The first step of the Calvin pathway is the first CO₂ fixation step.
• Respiration is the reaction where RuBP combines with CO₂ to form 2 molecules of 3PGA, that is catalysed by RuBisCO.

RuBP + CO₂ -> 2 X 3PGA

• RuBisCO has a much greater affinity for CO₂ than for O₂.
• In C₃ plants, some O₂ do bind to RuBisCO, and hence CO₂ fixation is decreased.
• The RuBP instead of being converted to 2 molecules of PGA binds with O₂ to form one molecule and phosphoglycolate in a pathway called photorespiration.
• In the photorespiratory pathway, there is neither synthesis of sugars, nor of ATP.

Biological catalysts: 

The molecules.that can speed up the chemical reactions in cells is called a biological catalyst.

Example: 
Enzyms as biological catalyst :

Enzyms are soluble protein molecules. They can speed up the chemical reactions in cells respiration,photosynthesis and making new protiens are include in this reaction. due to this reaction enzymes are some times called as biological catalyst.
In enzime catalized reaction, the substract is changed to the product via a high energy transition in the state. this state has a very short life cycle and it is stabilized by the enzyme
An example of this type of reaction is decomposition of hydrogen peroxide into water and oxygen. Although the reaction is strongly favored thermodynamically, it is very slow unless catalyzed

The 5 kingdom classification is largely the most accepted system of modern classification mainly because of the phylogenetic placing of different groups of living organisms.

This system of classification looks more scientific and natural.

There is far less overlap and confusion in this system, as compared to the original two kingdom classification.

Grouping of all unicellular eukaryotes under the kingdom Protista has solved many problems, particularly related to the position of organisms like Euglena.

Separation of prokaryotes into an independent kingdom is justifiable because they differ from all other organisms in their general organization

The five-kingdom classification gives a clear indication of cellular organization and modes of nutrition, the characters which appeared very early in the evolution of life.

Anaerobic respiration is also used by multi-cellular organisms, like us, as a temporary response to oxygen-less conditions. During heavy or intensive exercise such as running, sprinting, cycling or weight lifting, our body demands high energy. As the supply of oxygen is limited, the muscle cells inside our body resort to anaerobic respiration to fulfill the energy demand.

Electron transport system is an integral part of the cellular respiration. Electrons are passed to oxygen through electron carriers which results in the formation of H2O. Electron carriers fall into three categories here.

(A) Electron Acceptors

NAD (Nicotinamide adenine dinucleotide) and FAD (Flavin adenine dinucleotide) both accept electrons and get reduced to NADH+H+ and FADH2.

This occurs during process glycolysis, oxidative decarboxylation of pyruvic acid and Krebs’ cycle.

(B) Respiratory Coenzyme Complexes

Complex I - NADH dehydrogenase: It oxidises NADH+ H+ and receives electrons or H+ ions from NADH+H+. These electrons are then passed to the mobile electron carrier ubiquinone.

Complex II - Succinate dehydrogenase: It oxidises FADH2 and the release electrons are sent to the mobile electron carrier ubiquinone.

Complex III - Cytochrome b + cytochrome c1: Cytochrome bc1 complex accepts electrons from ubiquinone and passes them to the mobile electron carrier cytochrome c.

Complex IV - Cytochrome a, a3: Complex IV accepts electrons from cytochrome c and passes them to oxygen. Oxygen acts as a final hydrogen or electron acceptor. Oxygen when combines with two protons it forms a molecule of water.

(C) Mobile Electron Carriers

Ubiquinone: It is a carrier between complex I and complex II. It transfers electrons from NADH to complex III.

Cytochrome c: It is a carrier between complex II and complex III. It transfers electrons to complex IV.

A floral formula is a system of representing the structure of a flower using specific letters, numbers and symbols. It represents floral symmetry, number of parts, connation and adnation, insertion, and ovary position. Floral formulas are useful tools for remembering characteristics of the various angiosperm families.  Their construction requires careful observation of individual flowers and of variation among the flowers of the same or different individuals.

A floral formula consists of five symbols indicating from left to right:

• Floral Symmetry
• Number of Sepals
• Number of Petals
• Number of Stamens
• Number of Carpels

The following symbols are used in floral formulae:

Some important points to be remembered while writing floral formulae:

• Fusion is indicated by enclosing the figure in brackets.
• Adhesion is indicated by drawing a line above the symbols of the floral parts.
• The position of the mother axis with respect to the flower is represented by drawing a dot on the top of the floral diagram.

Floral formulae of some important families of flowering plants:

Family Fabaceae:

Family Solanaceae

Family

Liliaceae

Morphology

• Earthworms have long cylindrical body divided into 100-120 similar short segments known as metameres .
• The dorsal surface of the body is marked by a dark median mid dorsal line along the longitudinal axis of the body and the ventral surface is distinguished by the presence of genital openings.
• Anterior end consists of the mouth and the prostomium, covering the mouth.
• The first body segment is called the peristomium, which contains the mouth.
• In a mature worm, segments 14-16 are covered by a prominent dark band of glandular tissue called clitellum, thus dividing the body into preclitellar, clitellar and postclitellar segments.
• Four pairs of spermathecal apertures and a pair of male genital pores are situated on the 5th -9th segments and 18^th segment, respectively.
• A single female genital pore is present in the mid-ventral line of 14th segment.
• Numerous minute pores called nephridiopores open on the surface of the body.
• Except the first, last and clitellum, there are rows of S-shaped setae in each segment, help in locomotion.

Nephridia are segmentally arranged coiled tubules which act as excretory organs in the earthworms. It performs the following function:
i. Regulate the volume and composition of the body fluids .
ii. Collects excess fluid from the coelomic chamber.
iii. Delivers the wastes through a pore to the surface in the body wallinto the digestive tube.

Ratio of the density of a substance to the density of water at 4° C is called specific gravity of the substance.