INHERITANCE AND SELECTION

INHERITANCE AND SELECTION

1. DEFINITION OF INHERITANCE; THE FEATURES THAT ARE PASSED ON FROM PARENTS TO THEIR OFFSPRING

   • PHYSICAL CHARACTERISTICS; HEIGHT, EARS, GENDER, HAIR;COLUR,TEXTURE, FACE SHAPE, EYE COLOUR, TEETH, SKIN COLOUR.

2. WE INHERIT GENES FROM OUR PARENTS WHICH WITH A COMBINATION OF OUT MOTHERS AND FATHERS CHARACTERISTICS THIS IS CALLED INHERITED VARIATION.

3. 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.

4. ENVIRONMENTAL VARIATION IS ALL TO DO WITH EFFECTS OF WHERE WE LIVE AND HOW WE ARE BROUGHT UP

5. INHERITED CHARACTERISTICS

   • HAIR COLOUR/ TYPE , EYE COLOUR, BLOOD GROUPS, INHERITED DISEASES ( CYSTIC FIBROSIS)

6. ENVIRONMENTAL CHARACTERISTICS

   • DIET, EDUCATION, LIVING CONDITION, ATHLETIC ABILITY (TRAINING)

7. 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

8. 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

9. 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)

10. 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