Biology

Learninsta presents the core concepts of Biology with high-quality research papers and topical review articles.

Habitat Definition and Examples

Habitat refers to the place where an organism or a community of organisms live, including all biotic and abiotic factors or conditions of the surrounding environment.

The collection of all the habitat areas of a species constitutes its geographical range. Organisms in a habitat interact with each other and can be part of trophic levels to form food chains and food webs.

Examples: In a xerophytic habitat, the camel is able to use water efficiently and effectively for evaporative cooling through their skin and respiratory system. They excrete highly concentrated urine and can also withstand dehydration upto 25% of the body weight. The hoofs and hump are also suitable adaptations for survival in this dry sandy environment.

In an aquatic media, maintaining homeostasis and osmotic balance is a challenge. So, marine animals have appropriate adaptations to prevent cell shrinkage. While freshwater organisms have suitable adaptations to withstand bursting of their cells.

Apart from this, organisms such as fish have a wide range of adaptations like fins (locomotion), streamlined body (aerodynamic), lateral line system (sensory), gills (respiration), air sacs (flatation) and kidneys (excretion).

Niche (or) Ecological Niche

As every organism has its unique habitat, so also it has an ecological niche which includes the physical space occupied by an organism and its functional role in the community. The ecological niche of an organism not only depends on where it lives but also includes the sum total of its environmental requirements.

Charles Elton (1927) was the first to use the term ‘niche’ as the functional status of an organism in its community. Groups of species with comparable role and niche dimensions within a community are termed ‘guilds’. Species that occupy the same niche in different geographical regions, are termed ‘ecological equivalents’.

Many animals share the same general habitat. But their niches are well defined. The life style of an individual population in the habitat is known as its niche. For example, crickets and grasshoppers are closely related insects that live in the same habitat, yet they occupy different ecological niches. The grasshopper is very active during daylight. It can usually be found on a plant, feeding on the plant parts.

Although the cricket lives in the same field, it is quite different. During the day, the cricket hides under leaves or plant debris and is usually inactive. It is active at night time (nocturnal). The cricket and the grasshopper do not interfere with each other’s activities in the same habitat. Thus, niche of an organism can be defined as the total position and function of an individual in its environment.

In a pond ecosystem, where Catla, Rohu and Mrigal are present, the ecological niche of the Catla is a surface feeder, Rohu is a column feeder and Mrigal is a bottom feeder. Their mouths are designed to suit their niche and hence have different positions and functions in their habitat (Fig.10.1).

Learninsta presents the core concepts of Biology with high-quality research papers and topical review articles.

Organism and Its Environment

Every living organism has its own specific surrounding, medium or environment with which it continuously interacts and develops suitable adaptations for survival there. Environment is a collective term which includes the different conditions in which an organism lives or is present. The common and infulencing factors in any environment are light, temperature, pressure, water, salinity. These are collectively referred to as Abiotic components.

Environments are variable and dynamic, in which temperature changes and light changes are diurnal and seasonal. These inflence the organisms inhabiting them. An organism’s growth, distribution, number, behaviour and reproduction is determined by the different factors present in the environment.

Ecology is the study of how living organisms interact with each other and with their environment. Abiotic factors are the parts of the environment that have never been alive, while biotic factors are the parts of the environment that are alive, or were alive and then died.

Ecology is the study of the interaction of organisms in an area with the surrounding environment. This interaction constitutes an overall adaptation of the organisms to their environment which also includes the continuity of species.

Ecology is the study of organisms and how they interact with the environment around them. An ecologist studies the relationship between living things and their habitats.

Environment is the living and non living things surrounding the living organism. An organism’s habitat refers to an ecological or environmental area inhabited by particular species of plants, animals, fungi, etc. It refers to an organism’s natural environment. Life has to adapt to specific environmental conditions.

Ecology is the study of how organisms interact with one another and with their physical environment. The distribution and abundance of organisms on Earth is shaped by both biotic, living-organism-related, and abiotic, nonliving or physical, factors.

7 Ecological Principles

The seven principles are:-

1. Maintain diversity and Redundancy
2. Manage connectivity
3. Manage slow variables and feedbacks
4. Foster complex adaptive systems thinking
5. Encourage learning
6. Broaden participation and
7. Promote polycentric governance systems.

Learninsta presents the core concepts of Biology with high-quality research papers and topical review articles.

Biotechnology of Ethical Issues

Biotechnology has given to the society cheap drugs, better friuts and vegetables, pest resistant crops, indigenious cure to diseases and lot of controversy. This is mainly because the major part of the modern biotechnology deals with genetic manipulations. People fear that these genetic manipulations may lead to unknown consequences.

The major apprehension of recombinant DNA technology is that unique microorganisms either inadvertently or deliberately for the purpose of war may be developed that could cause epidemics or environmental catastrophies. Although many are concerned about the possible risk of genetic engineering, the risks are in fact slight and the potential benefits are substantial.

Learninsta presents the core concepts of Biology with high-quality research papers and topical review articles.

Biotechnology Of Animal Cloning

Cloning is the process of producing genetically identical individuals of an organism either naturally or artificially. In nature many organisms produce clones through asexual reproduction.

Cloning in biotechnology refers to the process of creating copies of organisms or copies of cells or DNA fragments (molecular cloning). Dolly was the first mammal (Sheep) clone developed by Ian Wilmut and Campbell in 1997. Dolly, the transgenic clone was developed by the nuclear transfer technique and the phenomenon of totipotency. Totipotency refers to the potential of a cell to develop different cells, tissues, organs and finally an organism.

The mammary gland udder cells (somatic cells) from a donor sheep (ewe) were isolated and subjected to starvation for 5 days. The udder cells could not undergo normal growth cycle, entered a dormant stage and became totipotent. An ovum (egg cell) was taken from another sheep (ewe) and its nucleus was removed to form an enucleated ovum.

The dormant mammary gland cell/udder cell and the enucleated ovum were fused. The outer membrane of the mammary cell was ruptured allowing the ovum to envelope the nucleus. The fused cell was implanted into another ewe which served as a surrogate mother. Five months later dolly was born. Dolly was the first animal to be cloned from a diffrentiated somatic cell taken from an adult animal without the process of fertilization (Fig. 9.8).

Advantages and Disadvantages Of Cloning Animals

• Offers benefis for clinical trials and medical research. It can help in the production of proteins and drugs in the field of medicine.
• Aids stem cell research.
• Animal cloning could help to save endangered species.
• Animal and human activists see it as a threat to biodiversity saying that this alters evolution which will have an impact on populations and the ecosystem.
• The process is tedious and very expensive.
• It can cause animals to suffer.
• Reports show that animal surrogates were manifesting adverse outcomes and cloned animals were affected with disease and have high mortality rate.
• It might compromise human health through consumption of cloned animal meat.
• Cloned animals age faster than normal animals and are less healthy than the parent organism as discovered in Dolly.
• Cloning can lead to occurrence of genetic disorders in animals.
• More than 90% of cloning attempts fail to produce a viable offspring.

Learninsta presents the core concepts of Biology with high-quality research papers and topical review articles.

Biological Products And Their Uses

A biological product is a substance derived from a living organism and used for the prevention or treatment of disease. These products include antitoxins, bacterial and viral vaccines, blood products and hormone extracts. These products may be produced through biotechnology in a living system, such as a microorganism, plant cell or animal cell, and are often more difficult to characterize than small molecule drugs.

Though recombinant DNA technology it is possible to produce these biological products on demand. There are many types of biological products approved for use – they are, therapeutic proteins, monoclonal antibodies and vaccines. Health care and pharmaceutical industries have been revolutionised by biotechnological proteins.

Hormones and antibodies are produced commercially, primarily for the medical industry. Recombinant hormones like Insulin, Human growth hormone, Recombinant vaccines and recombinant proteins like human alpha lactalbumin are available today.

Animals are used as bioreactors to produce desirable proteins. Antibodies are substances that react against the disease causing antigens and these can be produced using transgenic animals as bioreactors. Monoclonal antibodies, which are used to treat cancer, heart disease and transplant rejection are produced by this technology. Natural protein adhesives are non toxic, biodegradable and rarely trigger an immune response, hence could be used to reattach tendons and tissues, fill cavities in teeth, and repair broken bones.