Classwork Series and Exercises {Biology – SS1: Living Things And Non Living Things

Introduction to Biology

Science is the study of natural things around us and biology as a branch of science is derived from the Greek word bios, “life” and the suffix –logia, “study of.” Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.  Biology generally recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the synthesis and creation of new species. It is also understood today that all organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable and vital condition.

Branches of Biology

·         Agriculture – the study of producing crops from the land, with an emphasis on practical applications

·         Anatomy – the study of form and function, in plants, animals, and other organisms, or specifically in humans

·         Biochemistry – the study of the chemical reactions required for life to exist and function, usually a focus on the cellular level

·         Botany – the study of plants

·         Cell biology – the study of the cell as a complete unit, and the molecular and chemical interactions that occur within a living cell

·         Ecology – the study of the interactions of living organisms with one another and with the non-living elements of their environment

·         Microbiology – the study of microscopic organisms (microorganisms) and their interactions with other living things

·         Molecular biology – the study of biology and biological functions at the molecular level

·         Physiology – the study of the functioning of living organisms and the organs and parts of living organisms

·         Zoology – the study of animals, including classification, physiology, development, and behavior.

Living Thing and Non-Living Thing

Living thing is any organism or a living form that possesses or shows the characteristics of life. Thus, they have an organized structure being made up of a cell or cells, requires energy to survive, ability to reproduce, grow, metabolize, respond to stimuli, move, respire and to adapt to the environment.

Examples of living things include the bacteria, protozoa, plants, fungi, animals, humans, etc. Viruses are not absolutely living or non-living. When outside their host, viruses are inactive and seemingly inanimate. When inside their host, they became active and alive, capable of utilizing the host cell‘s structures and replicate.

A non-living thing is one that lacks or has stopped displaying the characteristics of life. Thus, they lack or no longer displaying the capability for growth, reproduction, respiration, metabolism, and movement. They also are not capable of responding to stimuli and adapt to their environment. They also do not require energy to continue existing. Examples of non-living things are rock, water, and sun.

Characteristics of Living Things

1.   Feeding: All living organisms need to take substances from their environment to obtain energy, to grow and to stay healthy.

2.   Movement: All living organisms show movement of one kind or another. All living organisms have internal movement, which means that they have the ability of moving substances from one part of their body to another. Some living organisms show external movement as well – they can move from place to place by walking, flying or swimming.

3.   Breathing or Respiration: All living things exchange gases with their environment. Animals take in oxygen and breathe out carbon dioxide.

4.   Excretion: Excretion is the removal of waste from the body. If this waste was allowed to remain in the body it could be poisonous. Humans produce a liquid waste called urine. We also excrete waste when we breathe out. All living things need to remove waste from their bodies.

5.   Growth: When living things feed they gain energy. Some of this energy is used in growth. Living things become larger and more complicated as they grow.

6.   Sensitivity or Irritability: Living things react to changes around them. We react to touch, light, heat, cold and sound, as do other living things.

7.   Reproduction: All living things produce young. Humans make babies, cats produce kittens and pigeons lay eggs. Plants also reproduce. Many make seeds which can germinate and grow into new plants.

Differences between Plants and Animals

                PLANTS                                                             ANIMALS

1) Plants generally are rooted in one place and do not move on their own (locomotion).	Most animals have the ability to move fairly freely.
2) Plants contain chlorophyll and can make their own food, this is called Photosynthesis.	Animals cannot make their own food and are dependent on plants and other animals for food.
3) Plants give off oxygen and take in carbon dioxide given off by animals.	Animals give off carbon dioxide which plants need to make food and take in oxygen which they need to breathe.
4) Plants cells have cell walls and other structures differ from those of animals.	Animal cells do not have cell walls and have different structures than plant cells.
5) Plants have either no or very basic ability to sense.	Animals have a much more highly developed sensory and nervous system.
6) Growth is apical.	Growth occurs equally on all parts.

TESTS AND EXERCISES

1.   Which of the following is NOT a characteristic of life? (a) Movement (b) Respiration (c) Tissue (d) Reproduction  Answer: Tissue

2.   ————————- is the removal of waste from the body. (a) Irritability (b) Excretion (c) Adaptation (d) Growth  Answer: Excretion

3.   Plants contain chlorophyll and can make their own food by ———————– (a) Respiration (b) Mouth (c) Photosynthesis (d) Preying  Answer: Photosynthesis

4.   The ability to respond to stimuli is called ——————- (a) Irritability (b) Excretion (c) Adaptation (d) Growth  Answer: Irritability

5.   The following are the branches of biology except —————– (a) Ecology (b) Botany (c) Zoology (d) philosophy   Answer: Philosophy

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