Physiology - Genetics Flashcards
(89 cards)
1
Q
Genome
- how many pairs of chromosomes
- contains what
- intraspecies variation
A
- 23 pairs of chromosomes
- all genetic material in human cell
- 0.1% variation
2
Q
Diploid vs. haploid
A
Diploid: (2n) both sets of of DNA
- go through mitosis
haploid: (n) one set of chromosomes - go through meiosis
3
Q
what type of cell is haploid
A
gametes - sex cells
4
Q
Genome
- how many genes
- what percentage of genome is coding
A
- 20-25k genes
- 2% is coding
5
Q
what is the 98% of genome that is not coding?
A
“noncoding” but not junk
6
Q
Genome of eukaryote vs. prokaryote and implication
A
eukaryote - very little coding
prokaryote - 80% ish coding
-> level of complexity increases from pro to eukaryote
7
Q
List 3 types of non-coding region
A
- intron
- Intergenic DNA
- Functional RNA
8
Q
Intron
A
- part of DNA/transcript that doesn’t code for anything that ends up in a protein
- spliced out of transcriptional transcript before translation (mRNA processing)
9
Q
Intergenic DNA
A
- DNA between genes
- doesn’t code for protein, participates in regulation
10
Q
4 types of Functional RNA
A
- Ribosomal RNA (rRNA)
- Transfer RNA (tRNA)
- Piwi-interacting RNA (piRNA)
- Micro RNA (miRNA)
11
Q
Piwi-Interacting RNA fxn
A
helps with regulation
12
Q
Micro RNA
A
helps prevent suppression of translation
13
Q
5 Types of Non-coding DNA
A
- Pseudogenes
- Cis and trans segments
- repeat sequences
- viral elements and transposons
- telomeres
14
Q
Pseudogenes
A
vestigial gene regions, from embryonic stage or evolutionary basis
15
Q
Cis and trans segments
A
complimentary bind to keep things open
16
Q
Viral elements and transposons
A
Transposons - segments of DNA that are inserted into DNA from the outside (ex from a virus)
9% of our genome is viral or transposon
Another way of recombination, can be bad
17
Q
telomeres
A
- Long repeats at end of chromosomes
- Damage/shortening has to do with life cycle of the cell
18
Q
Mitochondrial DNA
- how many genes
- inheritance
A
- 37 genes
- maternal inheritance
- make proteins from inside the mitochondria vs. make in cytosol and pump across the cell
- Sperm only contribute DNA, egg has everything else including mitochondria :)
19
Q
DNA
- shape
A
- double stranded helix
- two strands run antiparallel
- helical/spiral shape
- nitrogenous bases line up
20
Q
Packing of DNA
A
- DNA
- DNA wraps around Histones
- Chromatin
- Chromosome
21
Q
What is form of active DNA during interphase
A
chromatin - serves as source of transcription
22
Q
During mitosis what configuration is DNA in
A
chromosome
23
Q
Chromosome can mean two things:
A
- one chromatid (not an “x”)
2. both sister chromatids (X shape) This just means the DNA has been replicated
24
Q
DNA replication
- when
- what happens
A
- interphase, just before mitosis starts
- chromatin is highly condensed into chromosome form
25
What holds two sister chromatids together
centromere
26
If able to see DNA under light microscopy, what does that indicate?
can see chromosomes, means cell going through mitosis
27
Karyotype
- picture representation of all the chromosomes
- pair homologous sets
- 22 autosomes
- 1 sex chromosomes (XX or XY)
- look for deletions, duplications, what sex is the person
28
main cause of human chrom. disorders
Nondisjunction:
- Failure of homologous pairs to separate during Meiosis I
- Failure of sister chromatid to separate during Meiosis II
29
Down syndrome
- aka
- characteristics
- susceptibilities
- sexually
- risk factors
- Trisomy 21 (extra chrome 21)
- facial features, short stature, heart defects, early Alzheimers, leukemia, usually intellectual deficiency
- sexually underdeveloped, sterile
- age of mother (older eggs) but can be nondisjunction of father's chrome 21
30
Patau Syndrome
- aka
- characteristics
- stats
- life expectancy
- Trisomy 13
- serious eye, brain, circulatory defects, cleft palate
- 1:5,000 live births
- rarely live more than a few months
31
Edward's syndrome
- aka
- characteristics
- stats
- life expectancy
- trisomy 18
- almost all organ systems affected
- 1:10,000 live births
- do not live more than a few months
32
List 2 sex chromosome disorders
- Klinefelter syndrome
| - Turner sydnrome
33
Klinefelter syndrome
- number of chromosomes
- characteristics
- 47 XXY
- male sex organs, small testes, sterile
- breast enlargement, other feminine characteristics
- normal intelligence
34
Turner syndrome
- number of chromosomes
- stats
- characteristics
- how many make it to birth
- 45 chromosomes 0X
- 1:5000 live births
- genetically female but don't mature sexually during puberty, are sterile
- short stature, normal intelligence
- 98% die before birth
35
What is significant about turner syndrome
only viable monody in humans
36
Two chromosome deletion disorders list
1. Cri du chat
| 2. Fragile X
37
Cri du chat
- what is genetic problem
- characteristics
- deletion of small portion chrom. 5
| - severe mental retardation, small head with unusual facial features, cry sounds like distressed cat
38
Fragile X
- what is genetic problem
- characteristics
- stats
- x chrome is fragile at one tip
- usually have 29 repeats at this end of X but people with this syndrome have 700 due to duplications
- 1:1500 males 1:2500 females
39
What is most common form of mental retardation
Fragile X
40
What is DNA backbone composed of
1. Pentose sugar
2. Nitrogenous base
3. Phosphate group
41
What link together in DNA strand (2)
- phosphate groups like up and down chain
| - base pairs H bond between strands
42
RNA
| - 3 major diff from DNA
- uracil instead of adenine
- ribonucleic acid not deoxyribonucleic acid
- functions as single strand
43
mRNA
transcript that codes for protein during translation
44
tRNA
knows two languages - nucleic acid and amino acid, functions during translation
45
what does semi-conservative mean in regards to DNA replication
DNA starts with two strands, each daughter cell gets one original strand and one replicated strand
46
what enzyme works during DNA replication and what does it do?
DNA polymerase
- opens DNA strands to create a reading section
- links the new strands to the original strand
- can find and fix DNA problems
47
Transcription
- where does it take place
- what happens
- what cell phase
- enzyme
- in nucleus
- coding region of DNA is transcribed into mRNA which later translates into protein
- interphase
- RNA polymerase
48
Translation
- what happens
- what RNA involved
- large and small ribosome units come together and protect mRNA transcript, provides reading frame to create proteins
- rRNA, mRNA, tRNA
49
what bond is made between amino acids during translation
peptide bonds
50
Cell cycle
- what stages during interphase
- other phase
- G1, S, G2 during interphase
| - mitosis is other stage
51
what happens right before mitosis
- replicate DNA
- condense DNA into chromosomes
- nuclear membrane breaks down
52
Mitosis
- definition
- what type of cell
- what type of daughter cell is created
- somatic cell division to produce two identical daughter cells/clones
- somatic cells
- diploid cells created
53
what is function of mitosis
- development
- growth
- cell replacement of damaged cells
54
Stages of mitosis
- prophase
- metaphase
- anaphase
- telephase and cytokinesis
55
Prophase
- chromatin coil to form chromosomes
- nuclear membrane breaks down
- centrioles divide, start to migrate to opposite sides of the cell
- centrioles start to make spindle fibers
56
Metaphase
- Chromosomes line up in the middle along equatorial plate
- Lined up by microtubules
- Centrioles are at outer poles, spindle fibers attach to chromosomes
57
Anaphase
Spindle fibers are reeled in by centrioles, pull each sister chromatid to separate sides
58
Telephase & cytokinesis
- Create cell cytoplasm, cytokinesis
- Rebuild nuclear membrane
- Get two identical daughter cells
59
Meiosis
- what is created
- two stages and overview of what happens
- 4 haploid gametes
- Meiosis I - tetrads separate
- Meiosis II - sister chromatid separate
60
Meiosis I
- Chromosomes replicate
- Line up homologous pairs of chromosomes and separate
- Crossover (recombination) of homologous pairs (one from mom and one from dad). Form tetrads - entangle and divide chunks of DNA. This helps with genetic variation
- At the end have two haploid daughter cells
61
Meiosis II end brief overview
Separate sister chromatid to end up with a total of 4 haploid daughter cells
62
Major difference between Meiosis I and Meiosis II
prophase - tetrads switch genetic information
63
Metaphase in Meiosis I vs. II
I - whole pairs are separated
II - sister chromatid are separated
(both during anaphase)
64
spermatogenesis vs. oogenesis
spermatogenesis - 4 equal sperm
| oogenesis - one big egg and 3 polar bodies
65
fertilization
two haploid cells (sperm and egg) going to make one diploid cell
66
Mendelian principle of dominance
if two forms of a gene are present, the dominant allele is expressed
67
Mendelian principle of segregation
in meiosis, two alleles separate so that each gamete receives one form of the gene
68
Mendelian principle of independent assortment
each trait is inherited independent of other traits
69
Allele
form of a gene
70
Gene
segment of DNA that form a protein
71
homologous alleles
two versions of the same gene
72
phenotype
- phenotype: what it looks like, what you can see (curly or straight)
- even if you can't see it like metabolic activity
73
genotype
- what is written in the genes, what two alleles are present
| - homozygous dominant, homozygous recessive, heterozygous
74
Sex linked chromosomes
- allele is carried on sex chromosome.
- creates gender differences in inheritance
- if deleterious, more often show up in male offspring (only in daughter if both father and mother are affected)
75
Incomplete dominance
- Three genotypes and three phenotypes
- hair wave is an example: straight, curly, somewhere in-between
- flowers: red, pink, white
76
Codominance
- nothing is hidden, everything is expressed, both alleles are expressed
- blood type is an example, A, B, AB
77
Multiple alleles
two or more alleles for a trait, blood type example
78
Polygenic traits
multiple genes for a trait - skin or hair color are examples, get a wide range
79
PKU
- genetic disease
- autosomal recessive
- 1:25,000
- metabolic disorder
- results in toxic levels of phe and decreased level of tyr
- developmental issues, seizures, microencephaly, decreased cerebral fn
- hypo pigmentation
- do a newborn screening, if have, reduce phe in diet
80
Sickle cell anemia
- autosomal recessive
- incomplete dominance: shows a spectrum of affect
- single nucleotide defect
- decreased O2
- chronic or acute
81
Sickle cell trait
- heterozygous have 40% Hbs
- resistance to malaria (benefit)
- 2.5 million in US
82
Cystic fibrosis
- autosomal recessive
- mutation in channel protein of sweat and mucous glands
- increased thickness of secretions
- respiratory, digestive issues and pancreas involvement
- 30 year average life expectancy
83
Polycystic kidney disease (PKD)
- autosomal recessive and autosomal dominant forms (recessive is more common)
- two forms: AD and AR
- nephron cell mutation
- HTN, HA, abd pain, hematuria, polyuria, back pain, kidney failure
- appears in 40-60 yo
84
Hemophilia
- A most common, also b and C (least common)
- impaired clotting cascade
- sex linked recessive (seen more often in males)
85
Neurofibromatosis
- three types
- tumors in skin, skeletal deformities, freckled pits and groin
- children with >6 cafe au lait spots are higher risk
86
Congenital disorders
- aka birth defects
- exist at birth
- ex. heart disease and neural tube defects
87
Teratogenesis
environmental factors affect in utero growth and development
88
what does susceptibility of teratogenesis depend on?
| - varies with what
- genotype of the conceptus and interaction with adverse environmental factors
- varies with developmental stage at time of exposure (some critical periods exist)
89
Four manifestations of deviant development
1. death
2. malformation
3. growth retardation
4. functional defect
