Chapter 1- Characteristics and Classifications of Living Things.pdf

IGCSE Biology Chapter 1- Characteristics and Classification of Living Things

1. Characteristics
and
Classifications of
Living Things

2. Characteristics
1. Movement
An action by an organism (or a part
of organism) causing a change of
position or place.
*how about plants?

3. Characteristics
(cont.)
2. Respiration
The chemical reactions that breaks
down nutrient molecules in living
cells to release energy for metabolism
*chemical equations for respiration?

4. Characteristics
(cont.)
3. Sensitivity
The ability to detect and respond to changes in the internal or external environment, and to make appropriate changes.
*what are the human senses and the
stimuli?

5. Characteristics
(cont.)
4. Growth
A permanent increase in size and dry
mass by an increase in cell number or
cell size (or both)
*when the human stops growing?

6. Characteristics
(cont.)
5. Reproduction
The processes that make more of the same kind of organism (species)

7. Characteristics
(cont.)
6. Excretion
The removal from the organism of toxic materials, waste products of
metabolism and substances excess in
requirements.
7. Nutrition
The taking in of materials for energy,
growth an development

8. Classification
Organisms were first classified by a
Swedish naturalist calledLinnaeusin a
way that allows the subdivision of living
organisms into smaller and more
specialisedgroups
The species in these groups have more
and more features in common the more
subdivided they get
He named organisms in Latin using
thebinomial systemwhere the scientific
name of an organism is made up of two
parts starting with thegenus(always
given acapital letter) and followed by
thespecies(starting with alower case
letter)

9. Classification
(cont.)
When typed binomial
names are always
initalics(which
indicates they are
Latin) e.g.Homo
sapiens
The sequence of
classification
is:Kingdom,Phylum,
Class,Order,Family,
Genus,Species

10. Binomial Sytem of Classification

11. How Organisms
are Classified
Organisms share features because
they originally descend from
acommon ancestor
Example: all mammals have bodies
covered in hair, feed young from
mammary glands and have external
ears (pinnas)
Originally, organisms were classified
usingmorphology(the overall form
and shape of the organism, e.g.
whether it had wings or legs)
andanatomy(the detailed body
structure as determined by
dissection)

12. As technology advanced,microscopes,
knowledge ofbiochemistryand
eventuallyDNA sequencingallowed us
to classify organisms using a more
scientific approach
Studies of DNA sequences of different
species show that themore similar the
base sequences in the DNA of two
species, the more closely related
those two species are(and the more
recent in time their common ancestor
is)
This means that thebase sequences in
a mammal’s DNA are more closely
related to all other mammalsthan to
any other vertebrate groups

13. •The sequences above show that Brachinusarmiger and Brachinushirsutus
aremore closely relatedthan any other species in the list as their DNA
sequences are identical except for the last but one base (B.armigerhas a T
in that position whereas B.hirsutus has an A)
•As DNA base sequences are used to code foramino acid sequences in
proteins, the similarities in amino acid sequences can also be used to
determine how closely related organisms are

14. Groups within
the Animal and
Plant Kingdoms
1.Vertebrates
2.Arthropods
3.Ferns
4.Flowering plants

15. Vertebrates
1)Fish
Vertebrates with scaly skin
Have gills
Fins
Eggs with no shells, laid in
water

16. 2) Amphibians
Vertebrates with no
scales on the skin
Egss with no shells, laid
in water
The tadpoles lives in
water (the adults
usually live on land)
The tadpoles have gills
for gas exchange (aduts
have lungs)

18. 3) Reptiles
Vertebrates with scaly
skin
Lay eggs with soft shells
4) Birds
Have feathers
Have beak
Frontal limb are wings
Lay eggs with hard
shells

21. 5) Mammals
Have hair on the skin
The young develop in uterus, attachd to the mother by
placenta
The females have mammary gland to produce milk
Different types of teeth
Have pinna (ear flap) on the outside of the body
Have sweat glands in the skin
Have diaphgram (?)

25. Arthropods
1) Insects
Three pairs of jointed legs
Have two pairs of wings
Breathe through the tracheae
The body is segemented into head, thorax and abdomen
Have a pair of antennae

27. 2) Crustaceans
Arthropods with with more than four pairs of jointed legs
Have two pairs of antennae
3) Arachnids
Arthropods withfour pairs of jointed legs
Have no antennae
The body is divided into cephalothorax ad abdomen

31. 4) Myriapods
Have many similar segments
Each of their body has jointed legs
Have one pair of antennae

33. Ferns
Plants with leaves call fronds
Ther parts; roots, stems, and leaves (fronds)
Do not produce flowers
Reproduce by spores produced on the undersides of their
fronds

35. Flowering Plants
They are plants with roots, stems, and leaves
Reproduce by using flower and seeds
The seeds are produced inside the ovary of the flower.
Typs of flowering plants:
1. Dictyledons
2. Monocotyledons

36. 1. Dicotyledons:
Have seeds with two cotyledons
Usually have main root with side roots coming out of it
(tap root)
The leaves have the network of veins
Have the petal of the flower in multiples of 4 or 5
Have vascular bundle in the stem, arranged in the ring.

37. 2. Monocotyledons
Seeds with one cotyledon
The root grow directly form the stem (fibrous root)
The leaves have parallel veins
The flower parts are multiple in 3
Have vascular bundle in the stem, arranged randomly