Table of Contents
Arrange these structures in order of lower level of organization to the upper level and write the level against each structure. Neuron, nervous system, electron, man, a mass of neurons, carbon, mitochondria, brain, protein?
Difficulty: Medium
Arrangement of structures in order of lower level of organization to upper level:
Structures |
Level of Organization |
1. Electron |
Sub-atomic level |
1. Carbon |
Atomic level |
2. Protein |
Molecular level |
3. Mitochondria |
Organelle level |
4. Neuron |
Cell level |
5. Mass of neurons |
Tissue level |
6. Brain |
Organ level |
7. Nervous System |
Organ system level |
8. an individual |
Individual level |
How would you define biology and relate it with its major Divisions?
Difficulty: Medium
Definition of Biology: Biology is the scientific study of life. Through this study, the scientists (biologists) do their best to understand, explain, integrate and describe the world of living things. The word "biology has been derived from two Greek words 'bios' meaning 'life' and 'logos' meaning ‘thought or reasoning’.
Relation of biology with its major divisions/Branches:
There are three major divisions of biology which study the different aspects of the lives of these groups.
Zoology: This division of biology deals with the study of animals.
Botany: This division of biology deals with the study of plants.
Microbiology: This division of biology deals with the study of microorganisms such as bacteria etc.
Draw a table showing the branches of biology and the studies these deal with?
Difficulty: Hard
Branch of Biology |
Studies deal with |
i. Morphology |
This branch deals with the study of the structures of living organisms. The study of internal structure is called anatomy. |
ii. Histology |
The microscopic study of tissues is called histology. |
iii. Cell biology |
The study of the structures and functions of cells and cell organelles is called cell biology. This branch also deals with the study of cell division. |
iv. Physiology |
This branch deals with the study of the functions of different parts of living organisms. |
v. Molecular biology (biochemistry) |
This branch deals with the study of the molecules of life; e.g. water, proteins, carbohydrates, lipids, and nucleic acids. The study of the biochemical reactions occurring in organisms is also included in this branch. Genetics: It is the study of inheritance. Inheritance means the transmission of characters from one generation to the other. Genetics provides important tools in the investigation of the structure and functions of genes. |
vi. Embryology |
It is the study of the development of a new individual from a fertilized egg. Embryologists study cell growth, differentiation, and morphogenesis (the process that gives rise to tissues and organs). |
vii. Taxonomy |
It is the study of the naming and classification of organisms into groups and subgroups. |
viii. Paleontology |
It is the study of fossils, which are the remains of extinct organisms. Paleontologists study the age and structure of fossils and on this basis study the process of evolution. |
ix. Environmental Biology |
It deals with the study of the interactions that exist between the organisms and their environment. All living and non-living factors that surround an organism, constitute its environment. |
x. Parasitology
|
This branch deals with the study of time, and parasites. You know that parasites are the organisms that take food and shelter from living hosts and, in return, harm their (hosts') lives. The structure, habitats, mode of transmission, life histories, and host-parasite relationships are studied in parasitology.
|
xi. Socio-biology |
This branch deals with the study of social behavior and the communal life of living organisms. |
xii, Biotechnology |
Biotechnology means the practical application of the knowledge about living organisms to carry out processes, which make substances for the welfare of mankind e.g. disinfection and preservation of food, preparation of insulin, biogas, etc. |
xiii. Immunology.
|
It is the study of the immune system of animals, which defends the body against invading microbes. |
xiv. Entomology |
It is the study of insects. Entomologists study the general characteristics and life cycles of beneficial and harmful insects. |
xv. Pharmacology |
It is the study of drugs and their effects on the systems of the human body. |
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Give points to advocate that Biology is linked with physics, chemistry, mathematics, geography and economics?
Difficulty: Hard
Relationship of biology to other sciences:
- Biophysics:
It deals with the study of the principles of physics, which apply to biological phenomena. For example, there is a similarity between the working principles of the lever in physics and the limbs of animals in biology,
- Biochemistry:
It deals with the study of the chemistry of different compounds and processes occurring in living organisms. For example, the study of the basic metabolism of photosynthesis and respiration involves the knowledge of chemistry.
- Biomathematics:
It deals with the study of biological processes using mathematical techniques and tools. It has both practical and theoretical applications in biological research. For example, to analyze the data gathered after experimental work, biologists have to apply the rules of mathematics.
- Biogeography:
It studies the occurrence and distribution of different species of living organisms in different geographical regions of the world. It applies the knowledge of the characteristics of particular geographical regions to determine the characteristics of living organisms found there.
- Bioeconomic:
It studies the organisms from an economical point of view. It includes the study of the cost-effectiveness and viability of biological projects. For example, the cost value and profit value of the yield of wheat can be calculated through bioeconomics, and benefits or losses can be determined.
How would you distinguish the biomolecules from other molecules? What is the criterion for classifying a biomolecule as a micro molecule or macromolecule?
Difficulty: Easy
An organism is formed by an enormous number of biomolecules of hundreds of different types. These molecules are the building material and are themselves constructed in great variety and complexity due to specific bonding arrangements.
Classification of Biomolecules:
Biomolecules may be classified as micro molecules and macromolecules.
Micro molecules:
micro molecules are with low molecular weight e.g. glucose, amino acids, fatty acids, etc.
Macromolecules:
Macromolecules are with high molecular weights e.g. starch, proteins, lipids, etc.
Conjugated Molecules:
Two different molecules, belonging to different categories, usually combine to form a conjugated molecule e.g. glycoproteins, lipoproteins, nucleoproteins, etc.
Describe the levels of organization of life?
Difficulty: Hard
- Subatomic and Atomic Level:
- Molecular level:
- Organelle and Cell level:
- Tissue level:
- Organ and Organ system level:
- Individual level:
- Population Level:
- Community level:
Biologists study biological organization at different levels. The list goes from simpler to complex levels.
1. Subatomic and Atomic Level: All types of matter are made up of elements and there are about 92 kinds of elements, found in nature. Each element is made up of a single kind of atom (a": not, tom: cut).
These atoms are the structures formed by many subatomic particles. The most stable subatomic particles are electrons, protons, and neutrons. Each of these is found in a definite number, in a specific atom.
Bio elements:
Out of the 92 kinds of elements that occur in nature, 16 are called bioelements. These take part in making the body mass of a living organism.
Out of these elements; only six (O. C, H, N, Ca, & P) make up 99% of the total mass. The other ten (K, S, CI, Na, Mg, Fe, Cu, Mn, Zn, & I) collectively make 0.1% of the total mass.
2. Molecular level:
In organisms, bioelements usually do not occur in isolated forms. Rather, atoms of different bioelements combine through ionic or covalent bonding. The stable particle formed by the bonding between different elements is called a molecule. Bioelements share their atoms in making biomolecules or molecules of life.
3. Organelle and Cell level:
An enormous number of biomolecules become associated in a particular way and form organelles. The organelles are sub-cellular structures and when they assemble, cells are formed. Each type of organelle is specialized to perform a specific function. For example; mitochondria are specialized for cellular respiration and ribosomes are specialized for protein synthesis. In this way, the functions of the cell are accomplished by structures. It is an example of the division of labor within the cell.
4. Tissue level:
In multicellular organisms, similar cells (performing similar functions) are organized into groups, called tissues. We can define tissue as a group of similar cells specialized for the performance of a common function. Each cell in a tissue carries on its life processes (like cellular respiration, and protein synthesis), but it also carries on some special processes related to the function of the tissue There are four major types of animal tissues i.e. epithelial, connective, nervous and muscular tissues. Epithelial tissue acts as the covering and glandular tissue. Connective tissue acts as the connecting and supporting tissue. Nervous tissue conducts messages and muscular tissue acts as the contracting tissue.
There are four major types of animal tissues i.e. epithelial, connective, nervous, and muscular tissues. Epithelial tissue acts as the covering and glandular tissue. Connective tissue acts as the connecting and supporting tissue. Nervous tissue conducts messages and muscular tissue acts as the contracting tissue.
5. Organ and Organ system level:
In higher multicellular organisms, particularly in animals, more than one type of tissue having related functions are organized together and make a unit, called an organ. Different tissues of an organ perform their specific functions and these functions collectively become the function/s of that organ.
For example, the stomach is an organ specialized for the digestion of proteins and for storing food. Two major types of tissue are organized in their structure. Epithelial (glandular) tissue secretes the gastric juice and muscular tissue performs contractions of stomach walls for grinding of food, mixing enzymes with food, and moving food to the posterior end. So, two tissues perform their specific functions, which collectively become the function of the stomach.
Note:
The organ system level is less definite in plants as compared to animals. The complexity of organ and organ system levels in animals is associated with a far greater range of functions and activities than in plants.
6. Individual level:
Different organs (in plants) and organ systems (in animals) are organized together to form an individual/organism. In organisms, various organs and organ systems are organized in such a way that all the functions, processes, and activities are coordinated. For example, when a man is engaged in continuous and hard exercise, not only his muscles are working but also there is an increase in the rate of heartbeat. This accelerated rate of respiration and heartbeat supplies more oxygen and food to the muscles which they need for continuous work.
Note:
In animals, regulation of activities (coordination) is achieved by the nervous system and hormones while in plants, coordination is brought about only by hormones.
7. Population Level:
Biologists extend their studies to the population level where they study interactions among members of the same species living in the same habitat. A population is defined as a group of organisms of the same species located in the same place, at the same time. For example, the number of rats in a field of rice in 2002, the number of students in biology class in the semester of 2008, etc. Similarly, the human population comprises the number of human beings in a particular city or country at a particular time.
Note:
At the population level, biologists study life in several new parameters, which cannot be considered at the individual (organism) level. For example gene frequency gene flow, age distribution, population density, and population pressure.
8. Community level:
A community is an assemblage of different populations, interacting with one another within the same environment. A forest may be considered a community It includes different plant species e.g. oak trees, ash trees grasses, bushes, etc; different species of microorganisms and fungi, and different animal species. Communities are collections of organisms, in which one population may increase and others may decrease. Usually, populations change due to fluctuations in abiotic factors and changes in the size of other populations.
Complex Communities:
Some communities are complex e.g. a forest community, a pond community, etc. Other communities may be simple e.g. a fallen log with various populations under it.
Simple Community:
In a simple community number and size of populations is limited so any change in biotic or abiotic factors may have drastic and long-lasting effects.
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Is there any division of labor among the cells of a colony? If you find a division of labor among the cells and tissue what level of cellular organization is it?
Difficulty: Easy
Yes, there is a division of labor among the cells of a colony. Such a type of division is found in multicellular organizations.
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