Chapter 2 biological beginnings

Question 1

Why might an extended childhood period have evolved?

Answer 1

because humans require time to develop a large brain and learn the complexity of human societies

Question 2

What is the swiss army knife theory?

Answer 2

Theory that, like a swiss army knife, the human mind is like a number of independent domains or tools

Question 3

What are chromosomes?

Answer 3

threadlike structures made up of DNA

Question 4

“Many of our evolved psychological mechanisms are domain-specific”

What does this mean?

Answer 4

the mechanisms apply only to a specific aspect of a person’s psychological makeup

Question 5

What is genetic expression? What is it affected by?

Answer 5

Genetic expression is the activity of genes. Both events outside and inside of the cell can promote or inhibit it, like stress, exercise, radiation

Question 6

What are some common genetic principles that determine how a genotype is expressed to create a particular phenotype?

Answer 6

1. dominant and recessive genes
2. sex-linked genes
3. polygenetic inheritance (like height- it’s influenced by many genes)

Question 7

What are some common chromosome abnormalities?

Answer 7

1. Down syndrome (extra chromosome 21)
2. Klinefleter Syndrome (XXY)
3. Jacob’s Syndrome (XYY)
4. Turner syndrome (XO)

Question 8

What are some common gene-linked mutations?

Answer 8

PKU- metabolic disorder, can cause mental retardation

Sickle-cell anemia- disorder that limits the body’s oxygen supply

Question 9

What are the 3 periods of pregnancy?

Answer 9

1. the germinal period
2. the embryonic period
3. the fetal period

Question 10

How long does the germinal period last?

Answer 10

the first two weeks after conception

Question 11

What happens during the germinal period?

Answer 11

The zygote is formed, undergoes rapid cell division, and becomes a blastocyst (or a hollow ball of cells that eventually becomes the embryo)

Question 12

When does the embryonic period occur?

Answer 12

from 2-8 weeks after conception

Question 13

What are the 3 layers of cells that an embryo forms?

Answer 13

1. endoderm- inner layer, develops into digestive and respitory systems
2. mesoderm- middle layer, develops into circulatory system, bones, muscles, excretory system and reproductive system
3. ectoderm- outermost layer, develops into nervous system, sensory receptors, and skin parts

Question 14

What happens during the embryonic period?

Answer 14

The clump of cells is now an embryo, 3 layers of cells that will eventually become every part of the body forms. Major structures like the brain, spinal cord, and heart start to form.

Question 15

When does the fetal period occur?

Answer 15

Two months to conception

Question 16

What happens during the first trimester?

Answer 16

The germinal and embryonic periods; the beginning of the fetal period

at 12 weeks (fetal period), it can move arms and legs, fingerprints are present, and sex is distinguishable

Question 17

What happens during the second trimester?

Answer 17

Fetal period;

rapid growth, movement can be felt, vision and hearing develop

Question 18

What happens during the third trimester?

Answer 18

fetal period;

lungs maturing, antibodies being transmitted, move to “head down” posision

Question 19

How long does each trimester last?

Answer 19

1st- conception- 12 weeks
2nd- 16- 24 weeks
3rd- 28- birth

Question 20

What are the 4 phases of brain develpment that occur during the prenatal period?

Answer 20

1. formation of the neural tube
2. neurogenisis
3. neural migration
4. neural connectivity

Question 21

What are some prenatal tests?

Answer 21

ultrasound, fetal MRI, chorionic villus sampling, amniocentesis

Question 22

What is a teratogen?

Answer 22

any agent that can potentially cause a birth defect

Question 23

What are some parental factors that can harm the embryo or fetus?

Answer 23

• maternal weight and diet
• maternal age
• maternal drug use
• maternal stress
• paternal exposure to lead, radiation, pesticides, and petrochemicals

Question 24

What are the 3 stages of birth?

Answer 24

1. Dialation of cervix
2. Pushing and birth of baby
3. Delivery of placenta

Question 25

What is the apgar scale?

Answer 25

a scale widely used to assess the health of a newborn 1 and 5 minutes after birth

evaluates heart rate, respitory effort, muscle tone, body color, and reflex irritability

Question 26

What is involution?

Answer 26

the process by which the uterus returns to its prepregnant size 5 or 6 weeks after birth