Basis of life

2. Everyday Science
TOPIC: The Basis of life- the cell, chromosome, genes, nucleic acids.
GROUP 1:
Members:
1. Ahsan Ali.
2. Muhammad Abubakar.
3. Sagheer Raza.
4. Areej Fatima Sajjal.
5. Ayesha Noor.
6. Jannat Bibi.
7. Muskan Rufi.

3. Basis of life
● Cell.
● Chromosome.
● Genes.
● Nucleic Acids.

4. Bases of life
● Life is “a characteristic of a living organism that distinguishes the latter
from a dead organism or a non-living thing”, as specifically distinguished by
the capacity to grow, metabolize, respond (to stimuli), adapt, and reproduce.
Life may also pertain to the biota of a particular region

5. CELL
● A cell is the smallest unit of life that can carry out all of the functions
of living organisms. Cells are the basic building blocks of all living
things, including plants, animals, fungi, and bacteria.
● Cells have a variety of structures and organelles that perform different
functions. These include the cell membrane, which separates the cell
from its environment and controls what enters and exits the cell, the
cytoplasm, which contains various organelles and is the site of many
metabolic processes, and the nucleus, which contains genetic material
(DNA) and controls the cell's activities.

6. ● Cell is the fundamental, structural and functional unit of all living
organisms.
● Cell differs greatly in size, shape and activities. For example,
Mycomplasma, the smallest cell are 0.3 micrometer in length while
bacteria could be 3 to 5 micrometer.
● Largest isolated single cell is the egg of an ostrich. Shape of the cell
may vary with the function they perform like disc-like, polygonal,
columnar, cuboid, thread-like or even irregular.

7. Different Parts of Cell:
Essential Parts of Cell: Essential parts of a cell are described below:
1. Ribosomes: The ribosomes manufacture protein molecules by following
blueprints encoded in messenger RNA. The ribosomes have complex
structure.
2. Endoplasmic Reticulum: The endoplasmic reticulum consists of a complex
of membranes that form internal compartments used in the synthesis and
transport of various compounds produced by the cell.
3. Nucleus: The nucleus contains the hereditary materials, DNA, which carries
instructions for the operation and perpetuation of the cellular machinery.
Complex molecular processes are involved in replicating the DNA.
4. Nucleolus: The nucleolus is a factory for the partial manufacture of
ribosomes.

8. 5. Microtubes: The microtubes form a complex lattice work that gives form to
the cell and enables it to systematically move and change shape.
6. Lyosomes: Lyosomes contain enzymes that break down unwanted material
within the cell.
7. Chloroplasts: The chloroplasts, found in plant cells, are complex hemical
factories that carry out photosynthesis.
8. Cellular Membrane: The cellular membrane is equipped with many complex
protein molecules that regulate the passage of molecules into and out of the
cell and act as sensors informing the cell of external conditions.
9. Mitochondria: The mitochondria are chemical factories that generate energy
for the cell through the controlled breakdown of food molecules.

9. ANIMALS VS PLANTS
Sr.
No.
Animals Plants
1.
2.
3.
4.
1.
2.
Points of Similarities Smallest building blocks of
animals are cells
Animals range from Unicellular to more complicated
organisms consisting of multicellular bodies.
Animals grow in number by reproduction.
Animals reproduce both sexually and asexually.
Points of differences
Animals are heterotrophic
Animals take oxygen and release carbon dioxide gas.
Smallest building blocks of plants are also cells.
Plants also range from unicellular to more complicated
organisms consisting of multicellular bodies.
They also grow in number by Reproduction.
Plants also reproduce both sexually and asexually.
Plants are autotrophic.
Plants take carbon dioxide and release oxygen gas.

10. Sr.
No.
Animals Plants
3.
4.
5.
6.
7.
8.
9.
10.
Animals are free to move from one place to the other.
Animals cells have no cell walls but they have cell
membranes.
There are small vacuoles in animals cells.
There is no chloroplast in animal cells.
Animal life is dynamic.
Animals need oxygen gas for their survival.
Animals do not carry a green pigment called
chlorophyll.
Centrosome containing centriole are present in animal
cells.
They show restricted motion.
Plant cells have cell walls made up of cellulose to
protect and surround the cell and cell membrane
There is a large Vacuole in plant cell.
There is chloroplast in plant cell.
Plant life is static.
Plants need carbon dioxide gas for their survival.
Chlorophyll is an important part of all plants necessary
for photosynthesis.
No such substance is present in plant cells.

11. Sr.
No.
Animals Plants
11.
12.
13.
4.
5.
6.
Animals respond quickly to external stimuli
In animals, Meiosis results in only one functional egg
in female and 4 functional sperms in male.
Plastids are usually absent in animal cell.
Metabolism forms toxic wastes which are removed by
excretion.
Cellulose is altogether absent in animal cell.
Reserve food material is usually stored as Glycogen.
Plants respond slowly to stimuli.
In plants, instead of egg or sperms, micro gametes and
mega gametes are formed.
Plastids are usually present in plant cell.
Metabolic wastes are seldom toxic and not excreted.
The skeleton of the body is made up of cellulose.
Reserve food material is stored as Starch grains.

12. There are two main types of cells:
1) Prokaryotic
2) Eukaryotic.
❖ Prokaryotic Cell:
Prokaryotic cells are simpler
and do not have a nucleus.

13. ❖ A prokaryotic cell is a type of cell that lacks a nucleus and other
membrane-bound organelles. Prokaryotic cells are typically smaller and
simpler in structure compared to eukaryotic cells. They are found in
bacteria and archaea, which are two of the three domains of life.
❖ Prokaryotic cells have a cell membrane that encloses the cytoplasm,
which contains the genetic material in the form of a single, circular
chromosome. They may also have plasmids, which are small, circular
pieces of DNA that carry additional genetic information.

14. ❖ Prokaryotic cells typically lack other membrane-bound organelles such as
mitochondria, endoplasmic reticulum, and Golgi apparatus that are present
in eukaryotic cells.
❖ Prokaryotic cells have a rigid cell wall that provides structural support and
protection. Some prokaryotic cells also have a capsule or slime layer
outside the cell wall that helps protect the cell from harsh environments and
allows it to adhere to surfaces.
❖ Prokaryotic cells may also have flagella or pili, which are structures that aid
in movement and attachment, respectively.

15. ❖ Eukaryotic Cell:
Eukaryotic cells are more
complex and have a nucleus
and other membrane-bound
organelles.

16. ❖ Eukaryotic cells are a type of cell that have a nucleus and other membrane-
bound organelles.
❖ They are found in all complex organisms, including plants, animals, fungi,
and protists. Eukaryotic cells are generally larger and more complex than
prokaryotic cells.
❖ The nucleus is a membrane-bound organelle that contains the genetic
material of the cell in the form of DNA. The DNA is organized into
chromosomes, which carry the genetic information that is passed from one
generation to the next.

17. ❖ Other organelles found in eukaryotic cells include mitochondria, which are
responsible for producing energy for the cell; the endoplasmic reticulum,
which is involved in protein synthesis and lipid metabolism; the Golgi
apparatus, which modifies and sorts proteins for transport to their final
destination; lysosomes, which break down and recycle cellular waste; and
the cytoskeleton, which provides structural support and allows for cell
movement.
❖ Eukaryotic cells also have a cell membrane, which separates the cell from
its environment and regulates what enters and exits the cell. The cytoplasm
is the fluid-filled region between the cell membrane and the nucleus, where
many metabolic processes take place.

18. Chromosomes
❖ Chromosomes are essential components of all living organisms.
❖ They contain genetic material in the form of DNA, which carries the
instructions for the development, growth, and function of an
organism.
❖ Chromosomes have been studied for over a century, and scientists
have made many significant discoveries about their structure,
function, and behavior.
❖ The nucleus of each cell contains a number of very small thread like
structure called chromosomes.

19. ❖ The term chromosome was introduced into the scientific vocabulary
by Waldeyer in 1888.
❖ Each chromosomes consists of hundreds of molecules of
nucleoprotiens called genes.
❖ In the nucleus of the cell, the chromosomes are present as two
identical sets which pair off, each pair consisting of two identical
sets which pair off, each pair consisting of two identical
chromosomes. Chromosomes are hereditary material.

20. Chemical Composition
The chemical constituents of chromosome are:
i. Deoxyribo Nucleic Acid (DNA)
ii. Ribo Nucleic Acid (RNA)
iii. Histones
iv. Acidic proteins

21. Importance of Chromosomal Studies:
Chromosomal studies are useful in:
i. Diagnosis of various chromosomal abnormalities like Turner’s
syndrome, and Down’s syndrome.
ii. Clinically, in investigation of patients with abnormalities of sexual
developments or infertility.
iii. In determination of sex of an unborn child.
iv. In large scale population surveys, e.g., to detect the effects of
occupational hazards on chromosomes in relation to various
environmental factors like cold, heat, chemicals and dust.
v. In new fields involving separation of ‘X’ and ‘Y’ bearing sperms.

22. Structure
❖ Chromosomes are structures made up of DNA and proteins.
❖ The DNA molecule contains the genetic information, while the
proteins help organize and compact the DNA.
❖ In eukaryotic cells, chromosomes are located in the nucleus and are
visible during cell division.
❖ Each chromosome consists of two identical copies, called
chromatids, which are joined at a region called the centromere.

24. Types
❖ There are two main types of chromosomes.
1- Autosomes 2- Sex chromosomes
1- Autosomes are chromosomes that are not involved in determining
an organism's sex. In humans, there are 22 pairs of autosomes.
2- Sex chromosomes, on the other hand, are responsible for
determining an organism's sex. In humans, females have two X
chromosomes, while males have one X and one Y chromosome.

26. Genes
❖ Genes are segments of DNA (deoxyribonucleic acid) that contain the
instructions for building and maintaining an organism.
❖ They carry the genetic information that determines an individual's
inherited traits, such as eye color, hair texture, height, and susceptibility
to certain diseases.
❖ Genes are located on chromosomes, which are structures within the
nucleus of a cell that contain the DNA. Humans have 23 pairs of
chromosomes, for a total of 46 chromosomes.
❖ Each chromosome contains many genes, and each gene is composed
of a specific sequence of nucleotides, the building blocks of DNA.

28. Types
There are different types of genes based on their function, location, and
inheritance pattern.
1. Structural genes: These genes provide the instructions for building proteins,
which are essential molecules for many biological functions.
2. Regulatory genes: These genes control the expression of other genes, either
by activating or repressing them.
3. Homeotic genes: These genes control the development and positioning of
body structures during embryonic development.
4. Alleles: These are different versions of the same gene that can produce
different variations of a particular trait

29. 6. Recessive genes: These genes are only expressed when both copies of the
gene are present, and the dominant gene is not.
7. Dominant genes: These genes are expressed even if only one copy is present,
and they will mask the expression of any recessive gene.
8. X-linked genes: These genes are located on the X chromosome and are
inherited differently between males and females.
9. Mitochondrial genes: These genes are found in the mitochondria, the energy-
producing organelles in the cell, and are inherited only from the mother.
Understanding the different types of genes can help us better understand how
traits are inherited and how genetic disorders can arise

30. Function of genes
● Control the function of DNA and RNA
● Protein are the important material in human body which help in enzymes
production(Important work of genes is making protein and enzymes
production)
● These enzymes play important role in conducting various chemical
processes and reaction in body.
● Genes consist of a particular set of instructions. For example: globin Gene
are instructed to produce hemoglobin
● In short Gene describe everything about living thing ,one or more Gene can
effect specific traits.

31. ● Capability to determine traits, For example: skin color, intelligence,
temperament, blood group, etc. They maintain the specificity of an
individual.
● Ability to undergo identical reproduction (Replication). They play vital role in
transmission of characteristics from parents to off-spring.
● Ability to undergo mutation. This term is used denote a physic-chemical
change in Gene which alter the effect on the characters influenced by it.
● Genes are very important for synthesis of various proteins and
enzymes of cell.

32. Intron Exon Intron Exon
Intron Exon Intron Exon
Exon Exon Exon Exon
Now it will bon: converted
Into a desired protein

33. Characteristics of Gene
● Replication gene is a unit of genetic material which able to replicate.
● Recombination capable of undergoing crossing over.
● It controls the development of the phenotype of the organisms.
● Genes regulates structure and metabolism.
● It governs the development and differentiation.
● The genetic information stored in the form of a specific sequence of
nitrogen bases.

34. ● The Gene has the quality to express itself.
● The Gene do undergo occasionally heritable change called mutation.
● The Gene has a evolutionary function.. Give rise to a new alleles of a
Gene due to mutation.
● Gene are capable for combined together or can be replicated during a
cell division.
● Gene are capable of self duplication production their own exact copies.
● If the position of Gene changes, character changes.

35. Nucleic acid
● Nucleic acids are biopolymers, macromolecules, essential to all known forms of life.
● They are composed of nucleotides, which are the monomer components: a 5-carbon sugar,
a phosphate group and a nitrogenous base.
● The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If
the sugar is ribose, the polymer is RNA; if the sugar is the ribose derivative deoxyribose, the polymer is
DNA.

36. ● Nucleic acids are naturally occurring chemical compounds that serve as the primary
information-carrying molecules in cells and make up the genetic material.
● Nucleic acids are found in abundance in all living things, where they create, encode, and
then store information of every living cell of every life-form on Earth. In turn, they function to
transmit and express that information inside and outside the cell nucleus to the interior
operations of the cell and ultimately to the next generation of each living organism.

37. ● The encoded information is contained and conveyed via the nucleic acid
sequence, which provides the 'ladder-step' ordering of nucleotides within the
molecules of RNA and DNA. They play an especially important role in
directing protein synthesis.
● Strings of nucleotides are bonded to form helical backbones—typically, one
for RNA, two for DNA—and assembled into chains of base-pairs selected
from the five primary, or canonical, nucleobases, which
are: adenine, cytosine, guanine, thymine, and uracil.

38. ● Thymine occurs only in DNA and uracil only in RNA. Using amino acids and
the process known as protein synthesis, the specific sequencing in DNA of
these nucleobase-pairs enables storing and transmitting coded instructions
as genes.
● In RNA, base-pair sequencing provides for manufacturing new proteins that
determine the frames and parts and most chemical processes of all life
forms.

39. Nucleic Acid Notation
● The nucleic acid notation currently in use was first formalized by the
International Union of Pure and Applied Chemistry (IUPAC) in 1970.
● This universally accepted notation uses the Roman characters G, C, A, and T,
to represent the four nucleotides commonly found in deoxyribonucleic acids
(DNA).
● Given the rapidly expanding role for genetic sequencing, synthesis, and
analysis in biology, some researchers have developed alternate notations to
further support the analysis and manipulation of genetic data.

40. ● Under the commonly used IUPAC system, nucleobases are represented by
the first letters of their chemical names: guanine, cytosine, adenine, and
thymine.
● This shorthand also includes eleven "ambiguity" characters associated with
every possible combination of the four DNA bases.
● The ambiguity characters were designed to encode positional variations in
order to report DNA sequencing errors, consensus sequences, or single-
nucleotide polymorphisms.
● The IUPAC notation, including ambiguity characters and suggested
mnemonics.

41. Function of nucleic acid
● Nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), carry
genetic information which is read in cells to make the RNA and proteins by
which living things function. The well-known structure of the DNA double
helix allows this information to be copied and passed on to the next
generation.

42. Nucleic Acid
❖ Nucleic acids are large biomolecules that carry genetic information in living
organisms.
❖ They are made up of nucleotides, which are composed of a nitrogenous
base, a five-carbon sugar, and a phosphate group.
❖ The five-carbon sugar in DNA is deoxyribose, while in RNA it is ribose. The
nitrogenous bases in DNA are adenine (A), guanine (G), cytosine (C), and
thymine (T), while in RNA, uracil (U) replaces thymine.
❖ The nitrogenous bases are connected to the sugar molecule by a glycosidic
bond, while the phosphate group is connected to the sugar molecule by a
phosphodiester bond.

44. Types
There are two main types of nucleic acids:
1. DNA (Deoxyribonucleic acid): DNA is the genetic material that stores
information for the development and function of all living organisms.
➔ It is a double-stranded molecule made up of four nucleotide bases: adenine
(A), thymine (T), cytosine (C), and guanine (G).
➔ These nucleotides pair up in specific ways (A with T, and C with G) to form
the rungs of the DNA ladder.
➔ The order of these nucleotides, known as the DNA sequence, carries the
instructions for the development and function of an organism.

45. 2. RNA (Ribonucleic acid): RNA is a single-stranded molecule that plays a key
role in the expression of genetic information.
➔ There are several types of RNA, including messenger RNA (mRNA), transfer
RNA (tRNA), and ribosomal RNA (rRNA). mRNA carries the genetic
information from DNA to ribosomes, where it is translated into proteins.
➔ tRNA delivers amino acids to the ribosomes, where they are added to the
growing protein chain. rRNA forms the structural and catalytic components
of ribosomes.

47. Nucleic acid analogue
● Nucleic acid analogues are compounds which are analogous (structurally
similar) to naturally occurring RNA and DNA, used in medicine and in
molecular biology research.
● Nucleic acids are chains of nucleotides, which are composed of three parts:
a phosphate backbone, a pentose sugar, either ribose or deoxyribose, and
one of four nucleobases.
● An analogue may have any of these altered.Typically the analogue
nucleobases confer, among other things, different base pairing and base
stacking properties.

48. ● Examples include universal bases, which can pair with all four canonical
bases, and phosphate-sugar backbone analogues such as PNA, which affect
the properties of the chain (PNA can even form a triple helix).
● Examples include universal bases, which can pair with all four canonical
bases, and phosphate-sugar backbone analogues such as PNA, which affect
the properties of the chain (PNA can even form a triple helix).

49. Artificial nucleic acids include:
● Peptide nucleic acid (PNA).
● Morpholino and locked nucleic acid (LNA).
● Glycol nucleic acid (GNA).
● Threose nucleic acid (TNA).
● Hexitol nucleic acids (HNA).

50. Nucleic acids are essential for life, as they contain the instructions for building
and maintaining living organisms. Understanding the structure and function of
nucleic acids is crucial for understanding genetics and developing treatments for
genetic disorders.