I hope my presentation will help in this first subtopic for chapter 6 in biology..anyway all the best!

1. VARIATION IN
ORGANISMS

6. This refers to differences among
organisms of the same species
due to the differences in the genes
they inherit and the environment
they survive in.

7. EXAMPLE:
Variation of apples

8. VARIATION IN
ORGANISMS
GENETIC
VARIATION
ENVIRONMENTAL
VARIATION

9. Environmental variations
• This refers to differences amongst organisms of the same
species due to the different factors of the environment they are
exposed to. Eg , exposure of organismto different
temperatures, light, humidity,nutrients etc
• Such variations, because they are not genetically acquired but
environmentaryacquired or influencedcharacters, can not be
inherited fromparents totheir offsprings.

10. GENETIC
VARIATIONS
Continuous
variation
Discontinuou
s variation

11. Genetic variations
• This refers to differences amongst organisms of the same
species due to the differences in the genes they inherit from
their parents.Eg some individuals are tall and others are short.
This is because they inherited different genes fromtheir
parents.
• Such variations can be inheritedbecause they are genetically
determined.

12. CONTINUOUS VARIATION
This is the type of variation of a given
character/trait where by differences among
organisms of the same species are slight and grade
into each other.
These characters can be measured and mean, mode and
median can be obtained. eg Height, weight, intelligence,
waist line, length and width of structures, skin colour,
yield of milk, fertility, number of grains on a maize cob.

13. Continuous variation is variation that has no
limit on the value that can occur within a
population. A line graph is used to represent
continuous variation and may be affected by
environment or genetic or both.
Some examples of continuous variation are :
height
weight
heart rate
finger length
leaf length

15. SUNBATHING CAN CAUSE
TANNING OF SKIN
DIFFERENT PEOPLE HAVE
DIFFERENT HEIGHTS

16. DISCONTINUOUS VARIATION
This the type of variation which
shows clear-cut and sharp differences
amongst organisms over a given trait.
Features persist through out the life time of
an organism. They show distinct differences.
Eg finger print, tongue rollers and non
tongue roller, colour blindness, blood group,
skin pigmentation (normal skin
colour/albinism) eye colour etc.

17. Discontinuous variation is variation that has distinct
groups for organisms to belong to. A bar graph is used
to represent discontinuous variation and is affected by
genetic only.
Some examples of discontinuous variation are:
tongue rolling
finger prints
eye colour
blood groups

19. NO MATTER WHAT YOU EAT, IT
CANNOT CHANGE YOUR BLOOD
GROUP
DIFFERENT PEOPLE
HAVE DIFFERENT HAIR
LINES.

20. CONTINUOUS VARIATIONS DISCONTINUOUS VARIATIONS
They refer to small, indistinct differences from
the normal condition.
They refer to large, conspicuous differences
from the parents.
They are already present in population. They are new variations through similar
variations might have occurred previously.
They are also known as fluctuations.
They are also known as mutations or spurts.
They are usually unstable and non-
inheritable. They are usually stable and heritable.
They are due to chance segregation of genes
during gamete formation, crossing over or
chance combination during fertilization.
They are produced by change in genes or
genome.
They can be represented by smooth curve. A curve is not produced.
They are very common in all organisms. They appear suddenly and in few cases only.