+ Life Span Development

+Life Span Development

http://www.youtube.com/watch?v=9DBdK8_7LFs

+

Genetics

+Very Beginning

At conception, you began life as a zygote, and was no bigger than a period.

This cell contained your unique blueprint or your genetic make-up, all inherited from your parents

+The Genetic Makeup Of A Cell

+Chromosomes

Your blueprint encoded from parents in these chromosomes

Threadlike structures made up of DNA – chemical basis of heredity

46 in each cell23 received from each parent

+Chromosomes

+Deoxyribonucleic Acid (DNA)

A complex double stranded molecule

Contains the inherited genetic information of each chromosome

+Genes

Unit of DNA on chromosome that encodes particular instructions for who you will become and how your body will function

Each gene has information like eye color, hair color, height, handedness

+Your Unique Genotype

At conception, you receive 23 chromosomes from your father’s sperm and 23 from your mother’s egg They match together to form 23 pairs

These 46 chromosomes represent your unique genotype (genetic makeup)

+Why are body cells so different?

Different cells develop because different genes are “expressed” or activated

Some genes are expressed for a few hours, some are always expressed, and some are never expressed

Example: all humans carry the genes to develop a tail, but we don’t because the gene is rarely activated in our lifetimes

+Human Genome

Complete set of DNA in the human organism

Human genome consists of 20,000 to 25,000 genes

All humans have same basic set of genes, but the genes can come in two different versions (alleles)

The unique combination of alleles is what makes your genotype (and you) special!

+Dominant-Recessive Gene Pair

Best known pattern of alleles

Dominant genes—will always be expressed if present

Recessive genes—will not be expressed unless they are in a pair

+Sex Chromosome

23rd pair of chromosomes

Determines a person’s biological sex

+Phenotype

Characteristics that are actually observed in an organism

Your blueprint is not set in stone—it can change depending on environmental factors

Example: Freckles are your dominant gene, but will only appear when time is spent in the sun

People can have very similar genotype, but their phenotypes will differ if they live in different environments

+Stop & Think

Quick draw!

Draw/write the steps to the creation of a zygote (fertilized egg)

+

Prenatal Development

http://www.youtube.com/watch?v=gaK0VPV9NlE

+What are the three times in a woman’s life when she can’t get pregnant?

Before puberty

After menopause

And when she is pregnant – (if she gets pregnant with another –SHE IS STILL PREGNANT)

ANY OTHER TIME – A WOMAN IS FERTILE

+Conception

Chromosomes from mother and father morph together to form a single cell, the zygote The fertilized egg

Over 9 months, this one cell develops into approximately a trillion cells that make up a newborn baby

Crazy!

+Prenatal Development

Prenatal defined as “before birth”

Prenatal stage begins at conception and ends with the birth of the child

Three stages of prenatal development

+Stage 1: Germinal (Zygotic) Period

First two weeks after conception

Single cell zygote rapidly divides and develops into a cluster of cells (embryo)

+Stage 2: Embryonic Period

Weeks 3-8 after conception

Most vulnerable stage

Organs and major systems of the body form, including sex organs

Embryo housed in protective, fluid-filled amniotic sac

Umbilical cord delivers nourishment, oxygen, and water to embryo

Placenta acts as filter to protect embryo from harmful things in mother’s blood

+Stage 2: Embryonic Period

Placenta can only protect against so much, and can not filter out the harmful substances in mother’s blood (teratogens) Can cause abnormal development and birth defects

Known teratogens: Radiation Toxic chemicals Viruses and bacteria Drugs taken by mother during pregnancy

By end of this stage, embryo begins to resemble human and weighs about an ounce

+Other Prenatal Influences on Development

Nutrition

Anxiety

Mother’s general health

Maternal age

+Stage 3: Fetal Period

2 months after conception until birth (longest stage)

Bodily growth soars

Movement occurs

Brain cells multiply

Fetus gains 3-4 pounds

Age of viability (22-26 weeks)

+

+

http://www.youtube.com/watch?v=sVB0qTiq5jU

+Discussion

1. What is conception?

2. What is a zygote?

3. After the germinal stage, what is the next stage?

4. What are the main characteristics of the embryonic stage?

+

Why should you stop drinking, smoking, doing drugs while

pregnant?

+

+ Neural Tube Defects

+

+Smoking and Birth Weight

+Writing Prompt

Your friend is pregnant with her first child. She is a long-time smoker and still has a beer with dinner when she goes out (she’s 21!). Knowing what you know about pregnancy, what would you tell her? What would you show her?

5 sentences; use specifics!

Use back of quick draw to write

+

The Beginnings of Life:

The Newbornhttp://www.youtube.com/watch?v=m9QndNXcnCU

+Infant, Toddler, ChildInfant: First yearToddler: From about 1 year to 3 years of age

Child: Span between toddler and teen

So, are humans completely helpless at birth?

+

NO!!!!

+Infant Reflexes

Rooting—turning the head and opening the mouth in the direction of a touch on the cheek

Sucking—sucking rhythmically in response to touching baby’s lips

Grasping—putting a finger on baby’s palms will cause them to grip tightly

Reflexes later replaced with voluntary behaviors

+Senses

Newborn's senses are are very attuned to people

Babies 10 minutes old will move head to follow face, but not other object

Within hours, newborns show preference towards mother’s voice and face over stranger

+Senses

Newborn’s vision is extremely nearsighted at birth (can see close objects more clearly)6-12 inches is optimal

The world is still pretty fuzzy for infants in first few months

+

Physical Development in Infancy and

Childhoodhttp://www.youtube.com/watch?v=T7lL1jnwZOs

+Neural Development

+MaturationBiological growth processes that enable orderly changes in behaviorVision maturesBrain growsSenses sharpen

Motor Development

Includes all physical skills and muscular coordination

When did you first roll over, sit up, walk, ride a bike???

+ Motor Development

+

Social Development in Infancy and Childhood

+Temperament

Instinctive predispositions to consistently behave and react in a certain way

+Temperament

A baby’s temperament is apparent after just a few hours of birth“easy” babies – eat and sleep regularly

“difficult” – unpredictable, intense, & irritable

“slow-to-warm-up” – low activity level, withdraw from new, adapt slowly

+Temperament-Reactivity The high-reactivity – babies react intensely to new experiences and strangers

Low reactivity – babies are calmer and bolder, more sociable

+Temperament

Differences in temperament have genetic biological basis

Can also be influenced by environment and cultural attitudes

Your temperament as a baby can change into childhood and older stages of life

+AttachmentAn emotional tie with another person resulting in seeking closeness

Children develop strong attachments to their parents and caregivers.

Body contact, familiarity, and responsiveness all contribute to attachment.

+Factors Affecting AttachmentNeglect, abuse, and deprivation adversely affect attachmentHowever, differences in normal child-rearing practices have no affect

+

Daycare does not affect attachment

Temperament, chronic stress, and rejection can affect attachment

Cultural expectations can also play a role

Factors Affecting Attachment

+Familiarity

Sense of contentment with that which is already known

Infants are familiar with their parents and caregivers.

+Responsiveness

Responsive parents are aware of what their children are doing.

Unresponsive parents ignore their children--helping only when they want to.

+Attachment Theory

Securely attached – children will explore their environment when primary caregiver (secure base) is present

Insecurely attached – children will appear distressed and cry when caregiver leaves and will cling to them when they return

http://www.youtube.com/watch?v=s608077NtNI

+ Harry HarlowDid research with infant monkeys on how body contact relates to attachment

The monkeys had to chose between a cloth mother or a wire mother that provided food

+

The monkeys spent most of their time by the cloth mother

+Effects of Attachment

Secure attachment predicts social competence

Deprivation of attachment is linked to negative outcome

A responsive environment helps most infants recover from attachment disruption