1. Hereditary vs. Environment
Parenting &
Child Development
Objective: 3.01
Hereditary vs. Environment

2. I want you to stand up if you have….
Father’s eye color and shape
Mother’s physical build
Father’s feet (appearance)
Mother’s hand size
Father’s hair texture and color
Mother’s skin color

3. What does all of this have to do with???
If you stood up, you received all of those genetic, physical features from your parents or grandparents.
We look the way we do because of our inherited traits
Let’s learn more!!!!!

4. Characteristics connected with the body Example:
Physical Traits are…
Characteristics connected with the body
Example:
Eye and hair color

5. Heredity
Passing on of certain characteristics from earlier generations.
Each person inherits many characteristics from their parents, which include, but not limited to:
ears
feet
skin color
physical build
color/shape of eyes
hair texture/color
blood type
size of hands

6. Heredity Every baby receives 46 chromosomes
(tiny threadlike particles in the nucleus of every cell)
These chromosomes come in 23 pairs.
2/46=23
2. The father’s sperm and mother’s ovum (egg) both contribute one chromosome to each pair.

7. Heredity Each chromosome has thousands of genes.
Determine child’s inherited characteristics.
For every inherited characteristic, a person receives two copies of a gene
1 from mother
1 from the father
Both are the same, the child has that characteristic.
Ex: 2 genes for green eyes gives the child green eyes.

8. Genes
Recessive
a. Recessive and Dominant Genes 1. Recessive is the weaker gene (-)
2. Dominant is the stronger gene (+)
Scenario:
If a person receives two different genes, such as one for blue eyes and one gene for brown eyes, the dominant gene will express the characteristic over the weaker gene.
Brown eyes are dominant while blue eyes are recessive.
Therefore, the child will he born with brown eyes.
Dominant

9. DOMINANT & RECESSIVE CHARACTERISTICS
DOMINANT & RECESSIVE CHARACTERISTICS
DOMINANT TRAITS
RECESSIVE TRAITS
eye coloring
brown eyes
grey, green, hazel, blue eyes
vision
farsightedness normal vision normal vision normal vision
normal vision nearsightedness night blindness color blindness*
hair
dark hair non-red hair curly hair full head of hair widow's peak
blonde, light, red hair red hair straight hair baldness* normal hairline
facial features
dimples unattached earlobes freckles broad lips
no dimples attached earlobes no freckles thin lips
other
immunity to poison ivy normal pigmented skin normal blood clotting normal hearing normal hearing and speaking normal- no PKU
susceptibility to poison ivy albinism hemophilia* congenital deafness deaf mutism phenylketonuria (PKU)

10. Recessive & Dominant Genes…
Blonde hair
What genes
did the little girl receive from which parent?
Mother
Straight hair
Mother
Eye color
??both??

11. Male & Female Symbol

12. Female/Male Determination
OVUM=EGG
Female cell needed for reproduction
SPERM
Male sex cell needed for reproduction

13. How do you get a boy or girl?
Sperm sex chromosome carries “X” OR “Y”
Y=BOY
Ovum sex chromosome carries “X”
X=GIRL
Who determines sex of the baby?
Father=ALWAYS!!!

14. Scenario
IF a sperm fertilizes THE egg and it’s an “X” chromosome, what will your baby be? BOY OR GIRL??
GIRL=“X” Chromosome!
IF the sperm fertilizes THE egg and it’s a “Y’’ chromosome?
BOY=“Y” Chromosome!
What chromosome did your father contribute?
X or Y?

15. A Unique Person
Heredity explains why brothers and sisters often resemble each other and why they can also look different.
Each sperm cell contains a different combination of genes.
When they combine in a fertilized egg, they produce a unique individual.
The particular combinations of genes brought together at conception determine traits.

16. !!TWINS!! Here’s how it works

17. Identical (matching) Twins
After fertilization of the ovum by the sperm, if the one
egg splits into two separate eggs its identical twins.
Have to be same sex, came from 1 sperm
Two Fetus’ in the mother’s womb= amniotic “sac” & placenta

18. Fraternal (not matching) Twins
If two separate sperm fertilize two separate eggs, the result is fraternal twins, which can be same or opposite sex based on chromosomes.

20. The Canadian Dionne sisters, 1947
The Canadian Dionne sisters, First (and only identical) quintuplets known to survive infancy. The chance of identical quintuplets being born is 1 in 57 million.

21. that surround and influence a person
Environment
People
Places
Things
that surround and influence a person
. The environment does not influence a person’s physical (bodily) traits.

22. Environmental Influences on Birth Defects
Not eating properly
Exposure
Diseases and/or infections
Chemicals
X rays
Accidental injuries
Toxoplasmosis-extreme high blood pressure
Harmful substances
Drugs
Alcohol
Nicotine
Cigarettes

23. Human Traits Inventory

24. Hereditary or Environmental Influences?
Directions:
Uniqueness of a child comes from his or her heredity and environment.
Look at the list below and distinguish between influences that can be linked to heredity and those that can be linked to environment.
If the influence is due to heredity, write an H in the blank.
If the influence is due to environment, write an E in the blank.

25. Answers Mary has a great sense of humor. E Sue has blue eyes. H
Billy and his brother Tommy look alike.
Sammy goes to the library often.
Karen plays the trumpet quite well.
E, H
Mary has brown hair.
Judy lives in a nice house.
Tom is tall like his father.
Dana always scores high on tests in school.
Chanda has dark skin.
Answers