Basic Principles of Human Genetics Wksh.

Question 1

Material of heredity that is carried in the nucleus of each cell in the body

Answer 1

DNA

Question 2

Body cells that divide by mitosis

Answer 2

Somatic cells

Question 3

What do somatic cells provide?

Answer 3

Growth and development for tissue replacement and repair

Question 4

Reproductive cells formed in the male/female gonads

Answer 4

Gametes

Question 5

How do gametes reproduce?

Answer 5

Meiosis (contain 1/2 the genetic material of the parent cell)

Question 6

What makes up the chromosomes?

Answer 6

22 matched pairs of autosomes that control most traits in the body

1 pair of sex chromosomes that determine sex and other secondary sexual traits

Question 7

Each of the 23 pairs of chromosomes is ______ in terms of composition and traits regulated

Answer 7

Homologous or homozygous (matched)

Question 8

Pictorial analysis of the number, size, and form of an individuals chromosomes

Answer 8

Karogram

Question 9

How is a karogram taken?

Answer 9

From a blood sample

Chromosomes are stained and cut out and arranged in specific numeric order according to size.

Question 10

How are the chromosomes of a karogram sample put in to determine the presence of gross chromosomal disorders? What does a normal karogram look like?

Answer 10

Put in groups A-G

Normal: 46XX or 46XY

Question 11

What are 2 predisposing factors for occurrences of chromosomal abnormalities?

Answer 11

Advanced maternal age (over 35) and exposure to teratogens

Question 12

What does it mean if there is an abnormal number of chromosomes?

Answer 12

More or less than required 46–can occur in the autosomes or the sex chromosomes

Question 13

What is an example of a chromosomal abnormality that results in an extra chromosome?

Answer 13

Down Syndrome is an example of an extra chromosome on the 21st allele

Question 14

What is trisomy?

Answer 14

The product of the union of a normal gamete with a gamete containing an extra chromosome—the result is an individual with 47 chromosomes in a cell

Question 15

What is Kleinfelters?

Answer 15

An extra X on the sex chromosome—> a male but with feminine traits

Looks like XXY

If it is XYY it is a male with aggressive masculine traits

Question 16

What is monosomy?

Answer 16

One chromosome of a pair is absent (only 45 chromosomes) in each cell

Question 17

T/F: Missing an autosome may result in death of the embryo

Answer 17

True

Question 18

The basic unit of heredity

Answer 18

Genes

Question 19

What do genes determine?

Answer 19

Traits—every characteristic one possesses, from eye color to the disease passed on as a genetic trait to offspring!

Question 20

Pair of genes coded the same for a particular trait

Answer 20

Homozygous

Question 21

Pair of genes coded different for a particular trait

Answer 21

Heterozygous

Question 22

Genes are ____ or _____ for a trait

Answer 22

Dominant or recessive

Question 23

Characteristic that will be expressed in the individual even if its partner gene is different

Answer 23

Dominant

EX: Gene for brown eyes is dominant; gene for blue eyes is recessive

A person with one gene from each parent will have brown eyes

Question 24

Characteristic will be expressed only if carried by both chromosomes of a pair

Answer 24

Recessive gene

EX: 2 genes for blue eyes are required for a person to have blue eyes; 2 genes for CF is required for offspring to inherit the disease

Question 25

What kind of inheritance is this: Abnormal gene is dominant; a disorder is expressed when the dominant gene is present even if the other gene in a pair is normal

Answer 25

Autosomal dominant inheritance (mendalian)

Question 26

What are some examples of autosomal dominant inheritance?

Answer 26

Polydacyly (extra digit) Huningtons chorea Achondroplasia (dwarfism) Polycystic kidney disease

Question 27

Who is affected more in autosomal dominant inheritance: males or females?

Answer 27

Equally affected

Question 28

What kind of inheritance? Both genes of a pair must be abnormal for a trait (disorder) to be expressed

Answer 28

Autosomal recessive inheritance

Question 29

Autosomal recessive inheritance: Carriers of the trait (heterozygous individuals) are _____ but may pass the trait to offspring.

Answer 29

Unaffected clincially

Question 30

Who is affected more in autosomal recessive inheritance: males or females?

Answer 30

Equally affected!

Question 31

What are some examples of autosomal recessive inheritance?

Answer 31

Tay Sachs SCA CF

Question 32

A defective recessive gene is carried on the X chromosome

Answer 32

X-linked recessive Females are predominately carriers and males express the disorders when they receive the gene from their mother

Question 33

What are examples of X-linked recessive diseases?

Answer 33

Color blindness Hemophilia!!!! Duchenne muscular dystrophy!!!!!

Question 34

A defective dominant gene is carried on the X chromosome; expressed in both male and female offspring who inherit the defective gene

Answer 34

X-linked dominant

Question 35

Absence or defect in enzymes responsible for the metabolism of fats, proteins, or carbs

Answer 35

Inborn errors of metabolism

Question 36

What are examples of inborn errors of metabolism?

Answer 36

This leads to an accumulation of harmful substances--PKU is one PKU test is mandatory in infants before they can leave the hospital

Question 37

A pattern of inheritance reflecting the interaction of several genetic and environmental factors that create mild to severe defects

Answer 37

Multifactorial inheritance

Question 38

What are examples of multifactorial inheritance?

Answer 38

Cleft lip Cleft palate NTD Congenital heart disease

Question 39

Genetic counseling may occur in many contexts and settings. Examples?

Answer 39

Prenatal clinic Birthing unit Well-child clinic Family planning clinics

Question 40

Agents that cause birth defects

Answer 40

Teratogens

Question 41

The severity of defects from teratogens depend on what 3 things?

Answer 41

1. Timing of exposure (organogenesis is most vulnerable time) 2. Different susceptibility of organ systems 3. Strength of causative agent

Question 42

Teratogens: What are some examples of causative or suspected agents?

Answer 42

``` Maternal infection diseases Drugs and other substances Pollutants Radiation Maternal hypothermia Effects of maternal med disorders ```

Question 43

Avoiding fetal exposure--This ideally begins before conception. What is our role for informing women about possible teratogenic infections?

Answer 43

- They need to get the rubella immunization prior to pregnancy (3 months or more) - If titer is low, counsel women about situations to avoid - Avoid changing cat liter boxes because they have parasites in them and that can cause toxoplasmosis

Question 44

Avoiding fetal exposure: Drugs and other substances. What do we need to know about this to inform preg moms?

Answer 44

- There are pregnancy categories for meds - X= DONT TAKE IT!!!! - Women should eliminate use of non therapeutic drugs and alcohol - It is difficult to establish the effects of illicit drugs