Human Growth and Development Day #2 June 19, 2012 5:30 - 9:55 p.m.

Agenda for Class #2 Continue Methods Variables Activity Brief review of Genetics and Human Development Film: Prenatal Development Questions and distribute take home tests

Notes for Chapters 1 - 3 Methods Genetics Prenatal Development

Correlation Correlation – a relationship in which two or more variables change together Positive correlation – both variables change in the same direction The more you study, the higher your grades will be. Negative correlation – one variable increases as the other decreases The more checks you write, the lower your bank balance will be.

Sample Hypothesis Liver cell transplantation will reduce the need for dietary management for patients with phenylketonuria (PKU). IV = DV =

Sample Hypothesis Liver cell transplantation will reduce the need for dietary management for patients with phenylketonuria (PKU). IV = Liver cell transplantation DV = need for dietary management

Opening Day Survey Hypothesis: Men and women will differ in their preference for comfort/snack foods. Men are more likely to prefer salty or savory snacks whereas women are more likely to prefer sweet foods. IV = sex of the individual (variables are never the people; the variable is some characteristic of the person) DV = snack/comfort food preference; salty or sweet foods

Survey Results (combined classes to allow for larger sample) Sex Sweet Salty/Savory Not scored Male 7 1 Female 16 20 Total (N=52) 23 27 2 Can I support my hypotheses? If I were on a committee working with the bookstore and food service/ vending for the College, how might I use these results?

On your notecard, write your name, 6/19/12 and identify the variables. Hypothesis 1 Men are more likely to have more than $20 cash in their wallets than women. IV = DV = Hypothesis 2 Open-mindedness and critical thinking skills improve with the more years of education one has completed.

Hypothesis 3 Babies who are born to older fathers are likely to live longer lives than babies who are born to younger men. IV DV Hypothesis 4 Strokes are more likely to occur for people who sleep less than 5 hours per night than for people who sleep more than 5 hours per night.

Genetics and Genetics and Human Development

Human Genetics Each of us began life as a single cell weighing about one twenty-millionth of an ounce This cell contained our entire genetic code

Chromosomes Nucleus of each human cell contains chromosomes thread-like structures made up of deoxyribonucleic acid, or DNA. DNA is a complex molecule that has a double helix shape, like a spiral staircase, and contains genetic information

DNA Molecule For more detail: http://www.youtube.com/watch?v=CkcFqif7H5k&feature=related

Genes Genes - units of hereditary information short segments of DNA Genes direct cells to reproduce themselves and to assemble proteins Proteins the building blocks of cells the regulators that direct the body’s processes (Mader, 2008)

Enduring Nature of Genes Three processes by which cells split and are formed Mitosis Meiosis Fertilization.

Mitosis All body cells, except the sperm and egg, have 46 chromosomes arranged in 23 pairs These cells reproduce by a process called mitosis During mitosis, the cell’s nucleus—including the chromosomes—duplicates itself and the cell divides Two new cells are formed, each containing the same DNA as the original cell. http://www.youtube.com/watch?v=rgLJrvoX_qo&feature=related

Meiosis Sex cell division is different type of cell division Eggs and sperm (or gametes) are formed in meiosis A cell of the testes (in men) or ovaries (in women) duplicates its chromosomes but then divides twice, thus forming four cells Each of these has only half of the genetic material of the parent cell. By the end of meiosis, each egg or sperm has 23 unpaired chromosomes. http://www.youtube.com/watch?v=kVMb4Js99tA&feature=related

Fertilization During fertilization, an egg and a sperm fuse to create a single cell, called a zygote In the zygote, the 23 unpaired chromosomes from the egg and sperm combine to form one set of 23 paired chromosomes One chromosome of each pair is from the mother’s egg and the other from the father’s sperm. Each parent contributes half of the offspring’s genetic material. http://www.youtube.com/watch?v=vXNaTRs83hE&NR=1

The 23rd Pair of Chromosomes Ordinarily, in females the 23rd pair consists of two chromosomes called X chromosomes In males the 23rd pair consists of an X and a Y chromosome The presence of a Y chromosome is what makes an individual male

So, is this the karotype of a girl or a boy?

Genotype and Phenotype Genotype -- all of a person’s genetic material Phenotype -- observable characteristics Phenotypes include physical characteristics (such as height, weight, and hair color) psychological characteristics (such as personality and intelligence)

Genetic Principles Dominant-recessive genes Sex-linked genes Polygenically determined characteristics

Dominant-Recessive Genes Principle Dominant -- one gene of a pair always exerts its effects Recessive gene – exerts its influence only if the two genes of a pair are both recessive may be overridden by a dominant gene May be carried from generation to generation but not expressed in phenotype

Sex-Linked Genes X-linked inheritance -- mutated gene is carried on the X chromosome very different implications for males than females (Turner, 2006) males have no “backup” copy to counter the harmful gene females have a second X chromosome, which is likely to be unchanged Females who have one changed copy of the X gene are known as “carriers”

Polygenic Inheritance Genetic transmission is usually quite complex Few characteristics reflect the influence of only a single gene or pair of genes polygenically determined characteristics -- determined by the interaction of many different genes

Chromosome Abnormalities Down syndrome -- caused by the presence of an extra copy of chromosome 21 once in every 700 live births Women aged 16 - 34 are less likely to give birth to a child with Down syndrome Sex-Linked Chromosome Abnormalities

Sex-Linked Chromosome Abnormalities Klinefelter syndrome – extra X chromosome Fragile X syndrome -- results from an abnormality in the X chromosome X chromosome becomes constricted and often breaks Turner syndrome -- females have either an X chromosome missing or part of one X chromosome is deleted XYY syndrome – male has extra Y

Gene-Linked Abnormalities Phenylketonuria (PKU) – individual cannot properly metabolize phenylalanine, an amino acid once in every 10,000 to 20,000 live births left untreated, phenylalanine builds up in the child, producing mental retardation and hyperactivity

Sickle-cell anemia -- genetic disorder that impairs the body’s red blood cells most often in African Americans red blood cell becomes a hook-shaped “sickle” that cannot carry oxygen properly 1 in 400 African American babies is affected 1 in 10 African Americans is a carrier 1 in 20 Latin Americans is a carrier

Other diseases that result from genetic abnormalities cystic fibrosis diabetes hemophilia Huntington disease spina bifida Tay-Sachs disease

PRENATAL DEVELOPMENT AND BIRTH Film: Prenatal Development

Three Trimesters The germinal and embryonic periods occur in the first trimester The fetal period begins toward the end of the first trimester and continues through the second and third trimesters Viability (the chances of surviving outside the womb) occurs at the beginning of the third trimester. Age of viability – about 23-24 weeks on average

The Fetal Period Fetal period begins two months after conception and lasts for seven months Three months after conception-- fetus is about 3 inches long; weighs about 3 ounces At birth, the average American baby weighs 7 ½ pounds and is about 20 inches long

http://www.cerebralpalsyinfo.com/CP1.jpg

Multiple Births Monozygotic - identical Dizygotic – fraternal One ovum and one sperm Splits early in the process of dividing Must be the same sex Dizygotic – fraternal Several ova each fertilized No more alike than other siblings May be boys, girls or one (some ) of each Increased incidence with fertility technology

Dionne Quintuplets http://www.youtube.com/watch?v=KNleSaDse24&feature=related http://www.youtube.com/watch?v=WCmvQ2vdMv0

Conjoined Twins Monozygotic twins who do not completely separate Parts develop individually and other parts develop and grow together Example: the Hensel twins from Minnesota

http://www.youtube.com/watch?v=7ZUzi0RhBpM&NR=1&feature=endscreen http://www.youtube.com/watch?v=ISlXC33N2b4