Chapter Two Biological Beginnings

Question 1

The Genetic Process

Answer 1

each of us carries a “genetic code” that we inherited from our parents

Question 2

chromosomes

Answer 2

contain DNA - 23 pairs

Question 3

DNA

Answer 3

contain genetic information

Question 4

Genes

Answer 4

units of hereditary information composed of DNA
- each has it own function and its own location, and its own place on a particular chromosome. Scientists are trying to discover the specific location of genes that are linked to certain functions.

Question 5

genotype

Answer 5

a person’s genetic heritage, actual gene material

Question 6

phenotype

Answer 6

the way an individual’s genotype is expressed in observed and measurable characteristics.

Question 7

dominant-recessive genes principle

Answer 7

if one gene of a pair is dominant and one is recessive, the dominant gene exerts it effects, overriding the potential influence, of the other, recessive gene. A recessive gene exerts its influence only if the two genes of a pair are both recessive. If you inherit a recessive gene for a trait from each of your parents, you will show that trait. If you inherit a recessive gene from only one parent, you may never know you carry the gene.

Question 8

polygenic inheritance

Answer 8

many genes interact to influence a characteristic. Few psychological characteristics are a result of a single gene or pair of genes. Most are determined by the interaction of many different genes. There are about 20,000-25,000 human genes, so the possible combinations are staggering.

Question 9

reaction range

Answer 9

a range of potential expressions of a hereditary trait under varying environmental conditions.

Question 10

chromosomal abnormalities

Answer 10

normal set of 23 chromosomes not formed (1 missing or 1 extra)

Question 11

gene-linked abnormalities

Answer 11

result from harmful genes

Question 12

epigenetic view

Answer 12

development is the result of an ongoing, bidirectional interchange between heredity and environment.

Question 13

Summary

Answer 13

for most traits, a person’s experiences modify the way the genotype is expressed in a phenotype. for example, you may inherit the genotype for musical ability, but hoe it will be expressed depends on the environment. Heritability rarely exceeds 50%, therefore there is a lot of room for environmental influence.

Question 14

Fertilzation (conception)

Answer 14

single sperm cell unites with an ovum (egg), occurs within 24-72 hours.

Question 15

The Course of Prenatal Development

Answer 15

divided into three periods, lasting approximately 266 days.

Question 16

Germinal

Answer 16

conception to implantation (first two weeks) fertilized egg is called a zygote.

Question 17

embryonic (2 weeks to 8 weeks after conception)

Answer 17

most crucial time and rapid time of development as every major organ is beginning to develop. By the end the embryo weighs 1/30 ounce and is 1 inch long. During this stage damage that may occur is structural damage.

Question 18

fetal (8 weeks to birth)

Answer 18

about 32 weeks long, further development and continued growth, growth and fine tuning. earliest a fetus can be born and survive is 22-24 weeks-age of viability. by end 7 1/2 lbs and 20 inches long.

Question 19

teratogen

Answer 19

stunts growth and impairs functioning

Question 20

the brain

Answer 20

basic architecture is assembled during the first 6 months, and then 7-9 (and the first few years of life) are characterized by connectivity and functioning of neurons.

Question 21

amniocentesis

Answer 21

amniotic fluid is withdrawn and tested for any chromosomal or metabolic disorder.

Question 22

ultrasound sonography

Answer 22

visual picture of the developing fetus.

Question 23

infertility

Answer 23

inability to conceive after 12 months of trying

Question 24

stats

Answer 24

10-15% of couples are infertile

Question 25

female reasons for infertility

Answer 25

not ovulating, blocked fallopian tubes, disease that prevents implantation in the uterine wall

Question 26

males reasons for infertility

Answer 26

too few sperm (less than 250 millon), sperm lack mobility, blocked passageway (sperm not allowed to be released)

Question 27

Hazards to prenatal development

Answer 27

prenatal care is most crucial during the 1st three months (especially first 8 weeks) for optimal development.

Question 28

teratogens

Answer 28

any agent that causes a birth defect or negatively alters cognitive and behavior outcomes (only about 1/2 of all potential effects appear at birth) -important factors for outcomes are - dose (intensity), time of exposure and genetic susceptibility

Question 29

alcohol

Answer 29

is the leading known environmental cause of mental retardation.

Question 30

fetal alcohol syndrome

Answer 30

leading known cause of mental retardation. causes cognitive challenges, learning disabilities, ADD, facial malformation, cognitive, physical and social emotional challenges, 1 in 750 babies born with Fetal Alcohol Syndrome.

Question 31

Nicotine

Answer 31

causes premature delivery, low birth rate, increases risk of SIDS, respiratory problems, increased risk of ADD, effects of smoking not seen at birth, (learning disabilities, cognitive and socioemotional challenges occur later in life)

Question 32

First stage of birth

Answer 32

longest stage, having contractions, cervix opening up, 12-18 hours

Question 33

second stage of birth

Answer 33

pushing stage, @ 10cm, 45 minutes to an hour.

Question 34

third stage of birth

Answer 34

pushing out the placenta

Question 35

Apgar scale

Answer 35

named after Virginia Apgar who developed it, used to access the newborn baby's health, evaluates 5 different things on a scale of 0-2, score of 7-10 is good, over 90% of babies score a 9 or 10.

Question 36

low birth weight

Answer 36

infant that weighs less than 5 1/2 pounds

Question 37

preterm

Answer 37

born before 38 weeks or completion of 37 weeks.

Question 38

maternal factors contributing to preterm and low birth weight infants

Answer 38

age(over 35 or under 17), increased stress, poor nutrition, increase use of substances and poverty

Question 39

consequences of preterm and low birth weight

Answer 39

survival rate closely correlates with birth weight & lower IQ scores, ADD, asthma and respiratory problems.

Question 40

The postpartum period

Answer 40

the period after childbirth when the mother adjusts both physically and psychologically to the process of childbirth. (sleep deprivation, challenges with bonding, post partum depression, emotional and psychological adjustments)