Bacteria: 

These are single-celled microorganisms that play a crucial role in decomposition. They are very efficient at breaking down complex organic molecules, such as proteins, fats, and carbohydrates.

Fungi: 

These are multicellular organisms that also play an important role in decomposition. They secrete enzymes that break down organic matter, and then absorb the resulting nutrients.

Worms: 

Certain types of worms, such as earthworms, are also decomposers. They eat dead plant and animal matter and break it down into smaller pieces, which are then further broken down by bacteria and fungi.

Insects: 

Many insects, such as beetles, flies, and maggots, also play a role in decomposition. They consume dead organic matter and help to break it down into smaller pieces.

Other organisms: 

Other organisms, such as snails, slugs, and some types of bacteria, also play a role in decomposition by consuming dead organic matter.

All of these decomposers work together to break down dead organic matter and recycle nutrients back into the ecosystem. Without them, organic matter would accumulate and nutrients would be locked up, leading to a less productive and less diverse ecosystem.

In the 1860s, Mendel conducted a series of experiments on pea plants in which he observed the transmission of traits from one generation to the next. He discovered that traits are inherited in a predictable pattern and proposed the laws of inheritance, which are now known as Mendelian genetics.

Mendel's work went largely unnoticed for several decades, but it was rediscovered in the early 20th century by several scientists who were working on similar problems. These scientists built upon Mendel's work and developed new concepts and tools for studying genetics, including the discovery of the structure of DNA by Watson and Crick in 1953.

Since then, the field of genetics has exploded, and we now have a much better understanding of how genes are passed down from one generation to the next, how they are expressed, and how they interact with the environment. This knowledge has had a profound impact on our understanding of biology, medicine, and evolution, and has led to many important discoveries and innovations.

★ Amazon River: 

The Amazon River in South America is the largest in the world by volume, with a discharge greater than the next seven largest rivers combined. It is also the second-longest river in the world.

★ Nile River: 

The Nile River in Africa is the longest in the world, stretching over 6,650 kilometers (4,132 miles). It is historically and culturally significant to many countries in Africa and the Middle East.

★ Yangtze River: 

The Yangtze River in China is the longest river in Asia and the third-longest in the world. It is a major transportation route and source of hydroelectric power.

★ Mississippi River: 

The Mississippi River in North America is the fourth-longest in the world and is culturally and historically significant to the United States. It is also an important transportation route and source of freshwater.

★ Yenisei River: 

The Yenisei River in Russia is the largest river system flowing into the Arctic Ocean and is the fifth-longest river in the world. It is an important transportation route and source of hydroelectric power.

★ Congo River: 

The Congo River in Africa is the second-largest river in the world by volume and is an important transportation route and source of hydroelectric power.

★ Mekong River: 

The Mekong River in Southeast Asia is the twelfth-longest in the world and is culturally and economically significant to many countries in the region.

★ Danube River: 

The Danube River in Europe is the second-longest river in Europe and an important transportation route.

★ Ganges River: 

The Ganges River in India is culturally and spiritually significant to many people in India and is an important source of freshwater.

★ Indus River: 

The Indus River in Pakistan is historically and culturally significant and is an important source of freshwater for the region.

1. The term "embryo" denotes the juvenile stage of an animal while it is contained in the egg or the maternal body.

2. The processes that are involved in the transformation of the fertilized egg into a new adult individual are called ontogenic development.

3. Only gametes or generative cells go through the process of maturation or meiosis.

4. Historical development of species is called phylogenetic development.

5. Blastogenesis is the development of new individuals using asexual reproduction.

6. The third phase of development is Cleavage.

7. The proliferating cells in the ovaries are called oogonia.

8. Muscles and blood vascular system are made up of mesoderm.

9. The resulting embryo by infolding of the mesoderm and endoderm is called the gastrula.

10. Blastopore becomes the oral opening in Coelenterata.

11. The formation of spermatozoon and ripening of the egg is called gametogenesis.

12. The second phase of development is fertilization.

13. Endoderm forms the alimentary canal and the digestive glands.

14. Cleavage cells are called blastomeres.

15. The fifth phase of development is the phase of organogenesis.

16. In cleavage, the cells are arranged in a hollow spherical body called a blastula.

17. The group of cells that are segregated from the other cells of the embryo to form an organ is called the rudiment of the respective organ.

18. Larva possesses special organs which are absent in adults.

19. Developmental processes may be repeated in an adult during regeneration.

20. Ectoderm always gives rise to the skin epidermis and the nervous system.

21. When single layers of cells called blastoderm give rise to two or more layers of cells, germinal layers are formed.

22. The fourth phase of development is gastrulation.

23. The more general features in the embryo developed earlier than the more special features is the statement of Baer's Law.

24. Biogenetic law is proposed by Muller and Hackel.

25. The groups of animals having a common basic plan of organization are called the phyla of the animal kingdom.

26. The sixth phase of development is the period of growth and histological differentiation.

27. The generation of cellular diversity is called differentiation.

28. Some cells that can form new structures even in adults are called stem cells.

29. The gametes and their precursor cells are collectively called germ cells.

30. Aristotle supported the idea of epigenesis, which states that the organs of the embryo are formed de novo at each generation.

31. The organs are already present within the egg or sperm in miniature form is the theory of preformation.

32. In Deuterostomia, the blastopore develops into the anus.

33. Biogenetic law states that ontogeny is a shortened and modified recapitulation of the phylogeny.

34. The parts of the alimentary canal lined by ectoderm adjoining the mouth are known as the stomodeum.

35. The creation of an ordered form that involves coordinating cell growth, cell migration, and cell death is called morphogenesis.

36. The developmental pathway from germ cell to mature sperm is called spermatogenesis.

37. When sperm stem cells increase by mitosis, this is the proliferative phase.

38. GDNF is a paracrine factor called the Glial cell line-derived neurotrophic factor.

39. The precursors of sperm and oocyte are called Primordial germ cells.

40. The phase in which the round cells called spermatids eject most of their cytoplasm and become streamlined sperm is called spermiogenesis.

41. Gonocytes are true stem cells.

42. Sertoli cells nourish the developing sperm.

43. Type A spermatogonia can generate more than 1000 sperm per second in adult human males.

44. GDNF promotes the division of spermatogonial stem cells.

45. Stem Cell Factor promotes the transition to spermatogenesis.

46. Spermatogonia with high levels of stra8 divide to become type B spermatogonia.

47. Primary spermatocytes undergo meiosis to yield secondary spermatocytes.

48. The haploid cells formed from secondary spermatocytes called spermatids.

49. Acrosomal vesicle of sperm constructed from Golgi apparatus.

50. The acrosome forms a cap that covers the sperm nucleus.

Reference Books:
✨ An introduction to embryology by B.I. Balinsky.
✨ Developmental Biology by Scott F. Gilbert.

                       

Charles Robert Darwin

1. According to Darwin, Organic evolution is descent with modification.

2. Georges-Louis Buffon spent many years studying Comparative Anatomy.

3. Erasmus Darwin was the grandfather of Darwin and he was extremely interested in the questions of origin and change.

4. Theory of inheritance of acquired characteristics proposed by J.B. Lamarck.

5. Organs change as the need arises in the concept of Lamarck.

6. According to Lamarck, the disuse of any organ results in degeneration, and the use of any organ results in the high development of that organ.

7. In 1802, Lamarck published his theory of inheritance of acquired characteristics.

8. A change only passes on to the next generation, if it is based on genetic changes in germ cells.

9. Charles Robert Darwin was born on 12 February 1809.

10. Darwin made valuable contributions to beetle taxonomy.

11. Galapagos Islands are a group of volcanic islands 900 km off the coast of Ecuador.

12. James Hutton proposed the theory of uniformitarianism.

13. According to Hutton, forces of wind, rain, rivers, volcanoes, and geological uplift shape the earth today, just as they have in the past.

14. "Principles of Geology" was written by Charles Lyell.

15. Darwin found the fossil remains of an extinct hippopotamus-like animal which is now called Toxodon.

16. Galapagos tortoises weigh up to 250 kg.

17. Darwin noticed that tortoises from the drier regions had longer necks.

18. In Galapagos Islands, 14 species of finches arose from an ancestral group.

19. The finches of the Galapagos Islands provide an example of Adaptive Radiation.

20. "Essay on the Principle of Population" was written by Thomas Malthus.

21. Inherited variations arise by random mutation.

22. Traits that promote successful reproduction are said to be adaptive.

23. According to the theory of Natural Selection, all organisms have a far greater reproductive potential than is ever realized.

24. Adaptation refers to a process of change in evolution.

25. Adaptedness or fitness is a measure of the capacity for successful reproduction in a given environment.

26. Evolutionary adaptations lead to perfection.

27. Alfred Russel Wallace was an explorer of the Amazon Valley.

28. In 1859, both Wallace's and Darwin's papers were published in the Journal of the Proceedings of the Linnean Society.

29. Wallace believed that every evolutionary modification was a product of selection and, therefore, had to be adaptive for the organism.

30. Because resources are limited, existence is a constant struggle.

31. The combination of population genetics with Darwinian evolutionary theory is called the Modern Synthesis or Neo-Darwinism.

32. Biogeography provides evidence of prehistoric climates, habitats, and animal distribution patterns.

33. Adaptive traits are perpetuated in subsequent generations.

34. Darwin was nominated as a naturalist to travel around the world on the HMS Beagle in 1831.

35. Crick and Orgel have revived the theory of Panspermia.

36. According to the theory of chemosynthesis, the first protocells were products of chemical evolution.

37. The variety of small organic molecules accumulated in the sea during the first phase of chemical evolution is called Hot dilute Organic Soup by Haldane.

38. In 1953, Stanley Miller designed an apparatus for the synthesis of organic molecules.

39. Organic molecules became associated with one another to form molecular aggregates called protobionts or protocells.

40. The process of polymerization may occur in the second phase of chemical evolution.

41. Coacervate theory was proposed by Oparin in 1938.

42. Thomas Cech and Sydney Altam discovered that modern cells use an RNA catalyst called Riboenzymes.

43. Cyanobacteria were alone on the planet earth for 2 billion years.

44. Lynn Margulis was the first who proposed the endosymbiotic theory.

45. Chemoautotrophs can get energy by oxidizing certain inorganic substances.

46. The ancestors of mitochondrion may have been aerobic bacteria.

47. The protocell is hypothesized to have been a heterotrophic fermenter.

48. Adsorption on Clay Theory was proposed by Graham Cairn and Smith.

49. Phospholipids molecules automatically formed droplets called liposomes in a liquid environment.

50. RNA-first hypothesis was proposed by Orgel and Crick.

Reference Books:
✨ Origin, Evolution, and Distribution of Life by Syed Sabir Ali.
✨ Zoology by Miller and Harley.

1. The study of how the information stored in DNA codes for RNA and protein is called molecular genetics.

2. One complete spiral of DNA consisted of 10 base pairs.

3. Pyrimidine bases of DNA are cytosine and thymine. 

4. Nucleotide is the basic subunit of DNA and RNA.

5. Purine is the double-ring organic base.

6. Pentose sugar called deoxyribose is present in DNA.

7. Purine bases of DNA are Adenine and guanine.

8. The phosphate of a nucleotide attaches at the fifth (5') carbon of deoxyribose.

9. Hydrogen bonds between cytosine and guanine are three.

10. Some tissues like the liver contain occasional cells that are polyploid.

11. Each species has a certain content of DNA that is constant in all the individuals of that species called the C-value.

12. The bases and sugars in RNA and DNA are joined together into units called nucleosides.

13. A nucleotide consists of a nucleoside with a phosphate group attached through a phosphoester bond.

14. The bonds that join nucleotides together in DNA and RNA are called phosphodiester bonds.

15. According to Chargaff's rule, the amounts of adenine and thymine were always roughly equal, as were the amounts of guanine and cytosine.

16. The curving sides of the ladder in a DNA molecule represent the sugar-phosphate backbones of the two DNA strands.

17. The spacing between base pairs is 3.32 Å in a DNA molecule.

18. In the cell, DNA may exist in the common B form, with base pairs horizontal.

19. The Guanine-Cytosine content of a natural DNA can vary from less than 25% to almost 75%.

20. The temperature at which two strands of a DNA are half-dissociated, or denatured is called melting temperature.

21. Under the proper conditions, the two separated strands of DNA come back together again. This is called annealing or renaturation.

22. Mixing an RNA strand with a complementary DNA strand is called hybridization.

23. The length of human DNA is 1.1m.

24. DNA content per haploid cell is called C-value.

25. In 1953, James Watson and Francis Crick published the double-helical model of DNA structure.

26. Histones contain high content of basic amino acids which are lysine and arginine.

27. The unit of chromatin is called the nucleosome.

28. Nucleosome is a flat disc-shaped particle having a diameter of 11nm and a height of 5.7nm.

29. DNA is not free but is complexed with proteins in a structure called Chromatin.

30. When chromatin is isolated biochemically, it appears as a gelatinous substance that contains RNA, DNA, basic proteins called histones, and non-histone acidic proteins.

31. Histone H1 protein is non-conserved and has tissue-specific forms.

32. The diameter of beads in a chromatin structure is about 10nm.

33. Roger Kornberg proposed a model of nucleosome.

34. There are two turns of DNA per nucleosome.

35. Around 200 bp of DNA is present in a nucleosome.

36. The core DNA in a nucleosome is about 146 bp.

37. The histone H1 sealed off the two turns of DNA per histone octamer.

38. Linker DNA consists of 54 base pairs.

39. Non-histone proteins are very heterogeneous.

40. The most conserved histone proteins are H2A, H2B, H3, and H4.

Reference books:

1. Cell and Molecular Biology by E.D.P. De Robertis

2. Molecular Biology by Robert F. Weaver

3. Zoology by Miller and Harley 

For the pdf click here: 👇

https://sg.docworkspace.com/d/sIATm95ZVsJSwmQY

2. Gross Energy Intake is the total energy contained in the food an animal eats.

3. For any environmental factor, animals live within a certain range of values called the tolerance range.

4. A photoperiod is the length of a light period in a 24-hour day.

5. Circadian means "about a day".

6. The upset in the timing of daily activities like in a night shift job is called jet lag.

7. Changes in the tolerance range of animals in response to altered environmental conditions called acclimation.

8. A condition in which animals decreased their metabolism and lowered body temperature in daily activity cycles is known as torpor.

9. The rate of population increase under optimal conditions is known as the intrinsic rate of growth.

10. Diagonal Populations have a constant probability of death throughout their lives.

11. In exponential growth, the population increases by the same ratio per unit of time.

12. Carrying Capacity of an environment refers to the population size that a particular environment can support.

13. Camels can tolerate water loss of 25 to 40% of their total body weight.

14. Range of optimum defines the conditions under which an animal is most successful.

15. Sigmoid growth curve is an example of logistic population growth.

16. Density is the number of individuals per unit of space. 

17. Competition for resources is an example of density-dependent factors.

18. Territorial behavior is an example of direct interference.

19. Populations whose size tends to evolve toward their carrying capacity are called K-selected populations.

20. Natural selection promotes rapid population growth in r-selected populations.

21. Aposematic means " away from the sign".

22. When each species exerts a strong selective influence on the other during the evolution of ecologically related species, it is called coevolution.

23. The host that harbors the sexual stages of the parasite is said to be the definitive or final host.

24. When the effects of interspecific competition are less severe than the effects of intraspecific competition then coexistence can occur.

25. Animals that feed on grasses and other herbaceous vegetation are called grazers.

26. When one species gains protection by the resemblance to the other species, it is called mimicry.

27. The interaction in which one organism attaches itself to another organism only for travel is called phoresis.

28. When some invertebrates or small fishes swim into the mouth of larger fishes to remove ectoparasites, it is called cleaning mutualism.

29. The most common example of coevolution is seen in predator-prey relationships.

30. The two species with the same requirements of food, nest sites, habitat, and other conditions of life cannot coexist is called as competitive exclusion principle.

31. Less parental care of offspring is the characteristic of the r-selected population.

32. California red scale is an insect pest of citrus trees.

33. The animals having combined features of parasite and predator are said to be parasitoids.

34. When animals advertise their condition by conspicuous coloration that signals predators to stay away, it is called aposematic coloration.

35. Flour beetles survive only on water from cellular metabolism.

36. Animals feed on the leaves and twigs of woody plants and are called browsers.

37. Animals fed on fruits are called frugivores. 

38. An accounting of an animal's total energy intake and a description of how that energy is used and lost is called an energy budget.

39. The metabolic rate is expressed in milliliters of oxygen consumed per gram of body weight per hour.

40. The energy devoted to minimal maintenance and necessary activities is called existence energy.

Reference book: Zoology by Miller and Harley.