WE INHERIT GENES FROM OUR PARENTS WHICH WITH A
COMBINATION OF OUT MOTHERS AND FATHERS
CHARACTERISTICS THIS IS CALLED INHERITED VARIATION.
IDNETICAL TWINS BOTH INHERIT EXACTLY THE SAME
GENES AND ALTHOUGH THEY BOTH HAVE IDENTICAL
CHARACTERISTICS, 1 TWIN COULD BE HEAVIER DUE
TO SIMPLY EATING MORE.
ENVIRONMENTAL VARIATION IS ALL TO DO
WITH EFFECTS OF WHERE WE LIVE AND
HOW WE ARE BROUGHT UP
DIET, EDUCATION, LIVING
CONDITION, ATHLETIC ABILITY
(TRAINING)
THE INSTRUCTIONS FOR DESIGNING A NEW BABY ARE FOUND 2 PLACES:
EGG CELL (OVUM) MOTHER; NUCLEUS
SPERM CELL (FATHER); A SPERM
CELL NUCLEUS HEAD, FLAGELLUM
EACH NUCLEUS CONTAINS
CHROMOSONES WHICH CARRY
THE INSTRUCTIONS
HALVING AND DOUBLING
A HMAN CELL HAS 46
CHROMOSONES
ARRANGED IN 23
IDENTICAL PAIRS
DURING
REPRODUCTION, WHEN A
SPERM CELL AND EGG
CELL ARE MADE, THE
CHROMOSONES IN EACH
PAIR SPLIT UP
SPERM CELL NOW
HAS 23
CHROMOSONES
EGG CELL NOW
HAS 23
CHROMOSONES
AT FERTILISATION THE CHROMOSONES FROM THE
MOTHER AND FATHER JOIN TOGETHER MAKING 46
CHROMOSONES IN TOTAL
GENES
GENES ARE FOUND IN CHROMOSONES CONTAIN ALL THE INSTRUCTIONS
THAT WE INHERIT, GENES CONTAIN CERTAIN CHARACTERISTICS
(FEATURES) SUCH AS EYE COLOUR, HAIR TYPE, ABILITY TO ROLL TONGUE
THERE ARE 2 GENES FOR EACH
FEATURE (ONE IS GENERALLY
DOMINANT OVER THE OTHER)
SELECTIVE BREEDING
THIS IS WHERE HUMANS (FOR
THEIR OWN BENEFIT) DEVELOP
PATICULAR VARIETIES OF
PLANTS/ ANIMALS WITH
FAVOURABLE
CHARACTERISTICS. HOW?
THEY SELECT THE BEST PLANTS AND ANIMALS
FROM EXSISTING STOCK AND BREED FROM THEM
TO ACHIEVE OFFSPRING, WHO EVENTUALLY
DISPLAY THE BEST CHARACTERISTICS, EG. DAIRY
COW- HIGHER MILK YIELD BEEF COW- TASTIER
LEENER MEAT FAMILY PETS- GOOD LOOKS ,
SPEED, AGILITY,OBIDIENCE, DOMESTICATED
CROPS AND PLANTS - LETTUCE- FROSRT
RESISTANT, DISEASE/ PEST RESISTANT,
INCREASED PRODUCTION FLOWERING PLANTS-
COLOUR/SCENT, LARGE BLOOMS