A closer Look at ConceptionA closer Look at Conception

Chapter 5, Section 2Chapter 5, Section 2

pages124-129pages124-129

ObjectivesObjectives

Describe how personal Describe how personal Characteristics are inherited Characteristics are inherited

Explain how multiple births occur Explain how multiple births occur

Discuss possible solutions for Discuss possible solutions for infertilityinfertility

READ The genetic package on page 124-READ The genetic package on page 124-125125

GENETICS - The study of the way animals GENETICS - The study of the way animals & plants pass on to their offspring such as: & plants pass on to their offspring such as: eye color, hair color, height, body build, blood types, eye color, hair color, height, body build, blood types, intelligence, gender, etc.intelligence, gender, etc.

HEREDITY - Characteristics that a child HEREDITY - Characteristics that a child receives from both parentsreceives from both parents

Heredity, Environment, or BothHeredity, Environment, or Both

Hair colorHair colorEye colorEye colorSkin colorSkin colorHealthHealthPersonalityPersonalityStrength of eyesightStrength of eyesightPhysical strengthPhysical strengthRelationship with familyRelationship with family

Heredity, Environment, or BothHeredity, Environment, or Both

Relationship with friendsRelationship with friendsLevel of educationLevel of educationGenderGenderBody typeBody typeWeightWeightReligious InvolvementReligious InvolvementIQIQHeightHeightBlood TypeBlood Type

CELL: CELL: Basic unit of all living matter (Adult = over 10 trillion cells)Basic unit of all living matter (Adult = over 10 trillion cells)

NUCLEUS: Central point of cell / contains genetic coding for maintaining life systems and issuing commands for growth & reproduction

CYTOPLASM: Substance of a cell outside of the nucleus

CHROMOSOMES: 46 in each Nucleus (23 pairs)

GENES: bands on chromosomes (thousands of genes)

DNA on genes (billions of DNA)

?? ?? ?? ?? ?? ?? ?? ??How many chromosomes are there in each How many chromosomes are there in each cell?cell?

46 CHROMOSOMES or 23 PAIRS46 CHROMOSOMES or 23 PAIRS

How many chromosomes are in Reproductive How many chromosomes are in Reproductive (egg & sperm) or Germ cells?(egg & sperm) or Germ cells?

23 CHROMOSOMES23 CHROMOSOMES– (combined = the 46 chromosomes)(combined = the 46 chromosomes)

CELL DIVISIONCELL DIVISION

MITOSIS: MITOSIS: Cell divides by copying the DNA - cell splits - Cell divides by copying the DNA - cell splits - new cell with normal number of chromosomes (Cell growth & new cell with normal number of chromosomes (Cell growth & repair)repair)

MEIOSIS: MEIOSIS: Creates 1/2 sets of chromosomes Creates 1/2 sets of chromosomes

– Women = 23Women = 23 Men = 23Men = 23 Combined = 46Combined = 46

SEX DETERMINATIONSEX DETERMINATION

Read page 126 in Read page 126 in the textthe text

WHO DETERMINES THE SEX OF WHO DETERMINES THE SEX OF A BABY?A BABY?

Female Sex CellsFemale Sex Cells XXXX (Ovum or (Ovum or

Egg)Egg)

Male Sex CellsMale Sex CellsXYXY (Sperm)(Sperm)

Baby Girl = XX Baby Boy = XYBaby Girl = XX Baby Boy = XY– ConceptionConception is the union of an OVUM and the SPERM is the union of an OVUM and the SPERM

Gender is determined by the father!Gender is determined by the father!

DOMINATE Gene: More powerful - trait seen in DOMINATE Gene: More powerful - trait seen in personpersonRECESSIVE Gene: Weaker and hides in the RECESSIVE Gene: Weaker and hides in the background. Trait can only determine when two background. Trait can only determine when two of them are present - may show up in future of them are present - may show up in future generations.generations.CARRIER: Has a recessive gene that is not CARRIER: Has a recessive gene that is not visiblevisibleSEX-LINKED: Mother passes the recessive X to SEX-LINKED: Mother passes the recessive X to sonson– Color-blind male receives the trait from his Color-blind male receives the trait from his

mother. mother. – The mother is usually not color-blind herself.The mother is usually not color-blind herself.

B = BROWN eyes (dominate)B = BROWN eyes (dominate) b b = BLUE eyes (recessive)= BLUE eyes (recessive)

BB = BROWN eyesBB = BROWN eyes

bb = BLUE eyesbb = BLUE eyes

Bb = BROWN eyes but carry the Bb = BROWN eyes but carry the recessive BLUE eye generecessive BLUE eye gene

Multiple BirthsMultiple Births

Read pages 126-127Read pages 126-127

MULTIPLE BIRTHSMULTIPLE BIRTHSZYGOT: ZYGOT: the cell that is formed when a sperm the cell that is formed when a sperm fertilized an egg (ovum)fertilized an egg (ovum)

MONOZYGOT: MONOZYGOT: Identical TwinsIdentical Twins 1 Egg + 1 Sperm 1 Egg + 1 Sperm– Fertilized ovum splits into 2 identical cells - Fertilized ovum splits into 2 identical cells - Always the same Always the same

gendergender

DIZYGOT: DIZYGOT: Fraternal Twins Fraternal Twins 2 Eggs + different Sperm 2 Eggs + different Sperm– Will look different - May be different or the same genderWill look different - May be different or the same gender

MULTIPLE BIRTHS: MULTIPLE BIRTHS: More than 2 More than 2 – May be identical, fraternal or both - May be different or the same May be identical, fraternal or both - May be different or the same

gendergender

CONJOINED (Siamese) TWINS: CONJOINED (Siamese) TWINS: Ovum splits apart, but the Ovum splits apart, but the separation is not completed. Babies are joined at some part of their separation is not completed. Babies are joined at some part of their bodies.bodies.

Factors in Multiple PregnancyFactors in Multiple Pregnancy

Heredity:Heredity:

Race:Race:

Number of prior pregnanciesNumber of prior pregnancies

Delayed childbearing:Delayed childbearing:

Infertility treatment:Infertility treatment:

Jon and Kate GosselinJon and Kate Gosselin

Polycystic ovary syndromePolycystic ovary syndrome ( (PCOSPCOS) ) endocrine disorderendocrine disorder

affects approximately 5% of all women affects approximately 5% of all women

all races and nationalitiesall races and nationalities

most common hormonal disorder among most common hormonal disorder among women of reproductive age, and is a women of reproductive age, and is a leading cause of leading cause of infertilityinfertility..[2][2][3][3]