Development and Genetics Flashcards Preview

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Flashcards in Development and Genetics Deck (44):
1

What is the end product when a sperm and ovum combine?

Zygote

2

When a zygote is formed, it splits. When there are 8 cells, they each have equal potential. What does this mean?

They can all become everything a person needs for a body; if a cell is lost, a person can still fully develop from the 7 remaining cells

3

Term for inner cell mass (embryo) and trophoblast (placenta).

Blastocyst

4

What are the three germ layers?

1. Ectoderm
2. Mesoderm
3. Endoderm

5

Germ layer that becomes the skin and nervous system

Ectoderm

6

Germ layer that becomes the muscles and bones

Mesoderm

7

Germ layer that becomes the GI tract

Endoderm

8

Occurs during organogenesis; time where organs are particularly susceptible to injury, cells are rapidly dividing, cells are migrating, and important interactions between cells are occurring

Critical periods

9

When do most critical periods occur?

First 3 months of pregnancy

10

Fetal RBC contain fetal Hb which are replaced by adult Hb after birth. What is the difference between the two Hb's? Why does it make the switch after birth?

Fetal Hb has a higher affinity to O2; because of the higher affinity, it is also harder for the O2 to get to the baby's body tissue

11

What is the importance of surfactant and gestational age?

Surfactant isn't produced by the baby's body until later pregnancy; premies don't have enough surfactant to aid with breathing when born

12

Where are fetal RBC's made?

Liver

13

Study of birth defects

teratology

14

Anything that can produce a birth defect?

teratogen

15

What are physical teratogens?

1. X-rays
2. Other forms of irradiation

16

What are chemical teratogens?

1. Alcohol
2. Illegal drugs - cocaine
3. Thalidomide - limb deficiencies
4. Diethylstilbestrol (DES) - reproductive tract abnormalities and cancers

17

What are microbial teratogens?

- Direct effects:
1. Toxoplasma (cat and cat litter)
2. Other
3. Rubella
4. Cato megalovirus
5. Herpes virus
- Indirect effects:
Weakening of the mother cause fetal weight reduction, growth retardation, premature birth

18

The DNA sequence determines the sequence of proteins

DNA base pair

19

All of the DNA that determines a protein, along with the regulation of the synthesis of that protein

Genes

20

Structures that contain multiple genes and DNA regulatory regions

Chromosomes

21

What are the types of chromosomal abnormalities?

1. Structural
2. Numerical
3. Sex aneuploidy

22

Structural chromosomal abnormality where there is a loss of part of a chromosome

Deletion

23

Structural chromosomal abnormality where part of a chromosome is moved to another chromosome; may be moved to regulatory elements and turn expressions on or off

Translocation

24

What are 2 common diseases that are examples of structural chromosomal abnormalities?

1. Fragile X
2. Philadelphia chromosome (associated with myelogenous leukemia)

25

Numerical chromosomal abnormality that has the wrong number of chromosomes

Aneuoploidy

26

Numerical chromosomal abnormality where where there is a loss of one chromosome; incompatible with life

Monosomy

27

Name the numerical chromosomal abnormality where there is a gain of one chromosomes; most are lethal, but some will result in birth defects if they survive. Which chromosomes result in abnormalities, not death?

Trisomy; 13, 19, and 21

28

Numerical chromosomal abnormality where there is a loss of an X chromosome (OX)

Turner's syndrome; females only

29

Numerical chromosomal abnormality where there is a gain of an X chromosome (XXY)

Klinefelter's syndrome; males

30

Changes in DNA sequence that produce a change in function

Gene mutation

31

Different versions of the same gene; code for different characteristics

Allele

32

Alleles on different chromosomes are the same

Homozygous

33

Alleles on different chromosomes are different

Heterozygous

34

The genetic make up of a person's DNA; the alleles in their DNA

Genotype

35

How the genes are expressed in the individual; what you see

Phenotype

36

Trait that is expressed water homozygous or heterozygous; overshadow recessive genes

Dominant

37

True or false:

Not all people with an autosomal dominant gene will have the same S&S.

True; relates to penetrance and expressivity

38

Measure of whether the gene is expressed; a person may have the gene but not the disorder

Penetrance

39

Measure of how well the trait is expressed; how severe the disease is

Expressivity

40

Trait where both alleles are expressed

Codominant (blood types - AB)

41

Trait where only expressed of dominant alleles are not present; need to be homozygous

Recessive

42

What are 4 examples of recessive trait diseases?

1. Cystic fibrosis (1 in 25 whites are carriers)
2. Tay-sachs disease
3. Sickle cell anemia
4. Thalassemia

43

Disorders not linked to a single gene; involve several genes and exogenous factors

Multifactorial inheritance

44

Effect where persons with a more severe form of the disease have a greater chance of transmitting the disease

Dose effect