Natural sciences. 2º ESO

1. UNIT 1. LIVING
ORGANISMS

2. WHAT TO LEARN
 Chemical composition of living organisms.
 The vital functions
 The structure of cells
 The type of cells
 The cell theory

3. WHAT ARE LIVING THINGS?
Organisms with a similar chemical composition,
perform three vital functions and are made of cells.
CHEMICAL COMPOSITION
INORGANIC
COMPOUNDS
ORGANIC
COMPOUNDS
SIMPLE
MOLECULES
Ex: Water and
minerals
COMPLEX
MOLECULES
Ex: Sugar, lipids,
proteins, nucleic
acids.

4. THE THREE VITAL FUNCTIONS
NUTRITION INTERACTION REPRODUCTION
Take
substances
from the
environment
Perceive
changes in the
environment
called stimuli
and react to
them
Produce
descendents

5. WHAT IS A CELL?
All living things are made of cells.
It’s the basic
unit of life and
it can perform
the three vital
functions.

6. Types of living things
UNICELLULAR
ORGANISMS
MULTICELLULAR
ORGANISMS
ONE CELL
Ex: Bacteria
MANY CELLS
Ex: A dog
They can form groups
called COLONIES.
They have TISSUES,
ORGANS OR SYSTEMS

7. LIFE KINGDOMS
MONERA
(Unicellular)
Ex: Bacteria
and
Cyanobacteria
PROTOCTISTA
(Unicellular and
multicellular)
Ex: Protozoa
and algae FUNGI
(Unicellular and
multicellular)
Ex: Yeast and
mushroom
ANIMALS
(Multicellular)
Ex: A monkey
PLANTS
(Multicellular)
Ex: An apple tree

9. MULTICELLULAR: LEVELS OF ORGANISATION
WITH NO
TISSUES
WITH
TISSUES
BUT NOT
ORGANS
WITH
ORGANS BUT
NOT
SYSTEMS
WITH
SYSTEMS
-Multicellular
algae
-Mushrooms
-Moulds
-Sponges
-Moss
-Polyps
-Jellyfish
-Gymnosperms
-Ferns
-Angiosperms
-Planarians
-Fish
-Reptils
-mammals
-Birds
-Amphibians
-Molluscs
-Arthropods

10. THE BASIC STRUCTURE OF ALL
CELLS
 The plasmatic membrane: It surrounds the cell.
 The cytoplasm: It’s a jelly-like substance.
 The genetic material (DNA): It controls the cell’s
activities.

11. TYPES OF CELLS
 PROKARYOTIC CELLS: (Monera Kingdom)
 The DNA floats in the citoplasm.
 They have a cell wall.
 Sometimes they have flagella.
 EUKARYOTIC CELLS (Protoctist, Fungi, Plant, Animal
Kingdom)
 The DNA is in the nucleus.
 They have a lot of organelles, like mitochondria.
 Two types:
 Plant cells: They have chloroplasts to perform
photosynthesis and a rigid cell wall.
 Animal cells: They have centrioles to divide the
cell. They have cilia and flagella to move around.

12. Flagellum Cell wall
Plasmatic
membrane
Genetic
material Fimbria
Ribosomes
PROKARYOTIC
CELL

13. º
EUKARYOTIC
CELL
Chloroplast
Mitochondria
Membrane
Centrioles
Vacuole
Lysosomes
Nucleus
Cell wall

14.  What type of cells are they?
C
A B

15. ACTIVITIES
1. The following sentences are false, correct
them in your notebook.
a)All the living things except bacteria are made of cells.
b)All cells have plasmatic membrane, cytoplasm and a
nucleus.
c)Eukaryotic cells have a nucleus, but they do not have any
other organelles.
d)Eukaryotic plant cells have chloroplasts, but they do not
have mitochondria.
2. Why was the microscope important in the
discovery of cells?

16. 3. Classify the following compounds as
organic or inorganic:
Glucids:
Water:
Vitamins:
Proteins:
Lipids:
Nucleic acids:
Mineral salts:

17. 4. Match the terms in the
three columns:
1. Unicellular and
prokaryotic
2.Unicellular and
eukaryotic
3. Multicellular
without tissues
4.Multicellular
with tissues but
not organs
5.Multicellular
with organs but
not systems
6. Multicellular
with systems
1. Moss
2. Angiosperms
3. Arthropod
4.Yeast
5.Mammal
6.Amphibian
7.Bacteria
8.Sponge
9.Algae
a. Monera
b. Protoctist
c. Fungi
d.Plants
e.Animals

18. 5. Indicate which function the following actions belong
to:
a) Eating a fruit
b) Running away from a predator
c) Mating
d) Emigrating to a warmer area
e) Drinking water from a river
f) When flowers open to receive more sunlight
g) Laying eggs

19. 6. Complete the table using a X to show if the
organelle is present.
PROKARYOTIC EUKARYOTIC
ANIMAL
EUKARYOTIC
PLANT
Cell wall
Plasmatic
membrane
Cytoplasm
Nucleus
DNA
Mitochondria
Chloroplasts
Centrioles
Ribosomes