Chapter - One
Lessons on Life
Biology for 9 & 10
Exercise:
1. What is the significance of learning biology?
Ans:
Biology is one of the fundamental branches of science. As biology plays an important role in agriculture and medicine from the beginning of civilization it was practiced in different regions including Greece, Egypt, Middle East, India and China. Learning biology helps us create awareness about environmental pollution and conservation of natural environment.
2. Write down the names of the physical branches of biology.
Ans:
Physical branches of biology:
a) Morphology
b) Taxonomy
c) Physiology
d) Histology
e) Embryology
f) Cytology
g) Genetics
h) Evolution
i) Ecology
j) Endocrinology
k) Biogeography
3. Write down the names of the applied branches of biology.
Ans:
The name of the applied branches of biology are:
a) Palaeontology
b) Biostatistics
c) Parasitology
d) Fisheries
e) Entomology
f) Microbiology
g) Agriculture
h) Medical Science
i) Genetic Engineering
j) Biochemistry
k) Environmental Science
l) Marine Biology
m) Forestry
n) Biotechnology
o) Pharmacy
p) Wildlife
q) Bioinformatics
4. What is binomial nomenclature?
Ans: Normally the same organism ( Plant and Animal) is known by different names in different countries, even in different parts of the same country. So, to solve this problem Swedish Naturalist Carolus Linnaeus introduces a system of Nomenclature. So that scientists all over the world can know the organism by a single name. According to this system, the scientific name of an organism consists of two words. The first word is the genetic name, which begins with a capital letter and the second word is the species name, which begins with a small letter. This system is known as binomial nomenclature.
5. What are the ranks of classification?
Ans: Steps or ranks of classification:
Phylum / Division
Class
Order
Family
Genus
Species
6. What are the necessities of classifying organisms?
Ans: The main aim of classification is to know the vast and diverse living world accurately and classify them quickly and easily. It was the main field of his intense interest to classify organisms from the many botanical and zoological observations that he assembled from his many expeditions. The aim of classification is to acquire knowledge of the groups and subgroups of organisms, to maintain documentation of the accumulated information systematically, to present the knowledge concisely, and to take steps to conserve organisms or increase the number of species for the well-being of the living world.
7. In which branch of biology are insects discussed?
a) Entomology
b) Ecology
c) Endocrinology
d) Microbiology
8. The aim of classification is -
I) to know about the sub-ranks of organism
ii) to be able to name the units of organism
iii) to present the information in detail
Which one of the following is correct?
a. i & iii
b. i & ii
c. ii & iii
d. i , ii & iii
Look at the stem and answer questions 3 & 4.
9. What is the name of the organism shown in the picture above?
a. Amoeba
b. Diatom
d. Bacterium
10. The characteristics of the organism shown in the stem are -
i. They are able to move
ii. They are unable to produce food
iii. Their nucleus is well-structured
Which one of the following is correct?
a. i & ii
b. ii & iii
c. i & iii
d. i, ii & iii
11.
a. What are the units of classification?
b. Why is genetics part of the physical branches of biology?
c. How will you maintain continuity in naming the plant in Figure -2?
d. Analyse with reasons which organism is more advanced between
the two shown in Figure - 1 and figure -2.
Ans: a) Seven units are generally used in classification. Those are-
Kingdom/ Division
Class
Order
Family
Genus
Species
b) Genetics is the branch of biology that deals with genes and heredity. Genetics includes information regarding genes, genetic variation, and heredity in living organisms. These are all theoretical sciences. As physical biology deals with theoretical concepts, so genetics is under the branch of physical biology.
c) Maintain continuity in naming the plant in Figure -2, the rules that need to be followed are -
i) Latin words must be used in naming the plant scientifically.
ii) The name must contain two parts; the first part would be genus, and the second part would be species.
iii) The very first letter word of the scientific name should be in capital letter; the rest of the letters would be in small letter including letters of the second part as well.
iv) During printing, the scientific name should be printed in Italic front.
v) While writing, I would underline the genus and species term separately.
vi) I will add the name of the scientist who discovered the organism in the first place in a short form to the end of the scientific name of that organism. For example, short form of Linnaeus is L.
d) Figure-1 is mushroom and figure -2 is a dicotyledon plant. Of these two organisms, the dicotyledon plant is much more developed. The reasons behind this statement are discussed below -
i) Mushroom does not produce any flower, but the dicotyledon plant is a flowering plant. Flowering plants are always considered as superior organisms.
ii) Mushroom cannot produce its own food, but the plant can produce its own food via photosynthesis.
iii) Mushroom does asexual reproduction by producing spores. The dicot plant creates offspring via sexual reproduction.
iv) Mushroom's body cannot be divided into roots, stem, leaves, etc. But the dicot plant has roots, stems, and leaves.
v) Vascular bundle tissue system is a unique characteristic of the superior plant, which is absent in mushroom but present in dicot plant.
The word biology is derived from the Greek :
bios = Life
logos = knowledge
Biology = Science of life
It is an organized study of living things and of the theories that were devised to describe and explain the world of life.
# Why study Biology?
Ans: Studying biology helps us to understand our behavior and ourselves. Biological studies help to control pests, including crop pests such as locusts; pests of stored food such as flour beetles; pests that attack structures such as termites, fungi, and shipworms.
Growing suitable plants in parks, on beaches, and along waterways, and keeping aquarium fish at home.
The great ideas of biology-evolution, the living being in its environment, and the chemical and physical basis of life have influenced all fields of human thought.
