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

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

3. Notes for Chapters 1 - 3
Methods
Genetics
Prenatal Development

4. 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.

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

6. 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

7. 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

8. 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?

9. 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.

10. 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.

11. Genetics and Genetics and Human Development

12. 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

13. 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

14. DNA Molecule
For more detail:

16. 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)

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

19. 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.

20. 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.

21. 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.

22. 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

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

25. 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)

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

27. 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

28. 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”

29. 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

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

31. 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

32. 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

33. 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

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

35. PRENATAL DEVELOPMENT AND BIRTH Film: Prenatal Development

36. 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 weeks on average

37. 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

39. 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

40. Dionne Quintuplets

43. 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