Unit 3 Flashcards
Criminalistics
Largest area of forensic science, science applied to solving crimes
Forensic science
Science in the service of the law
Physical evidence
Objects or things connected to a crime Ex. Blood, DNA
Non physical evidence
Verbal testimony about a crime
Karyotype
Map or picture of chromosomes of a cell arranged into their homologous pairs
Mutation
change in the nucleotide sequence of DNA
Physical evidence vs non physical evidence
physical touch, non physical can’t touch
Three types of cells that do not contain a complete copy of the DNA what are they and what portion of a persons DNA do they contain
egg, sperm, and red blood cells
Give example of a genetic marker used in criminal investigation (especially in past)
Male (XY) vs Female (XX)
Do you need to be alive to win a Nobel prize
Yes
How many people can share a noble prize
3
Why are Nobel prizes given to research done many years in the past
time to prove itself worthy
What are two possible results of a mutation in a normal body cell
errors of replication or chemicals or radiation
DNA
molecule of heredity common to all life forms that is passed from parents to offspring
What are two possible results of a mutation in an egg or sperm cell
can be passed on, will be in all body cells
chromosome
a single large DNA molecule wrapped around proteins. chromosomes are located in the nuclei of most eukaryotic cells
nucleotides
the building blocks of DNA each nucleotide consists of a sugar, a phosphate, and a base. the sequence of nucleotide (As, Cs, Gs, and Ts) along a DNA strand is unique to each person
double helix
the spiral structure formed by two strand of DNA nucleotide bound together
DNA profile
a visual representation of a person’s unique DNA sequence
DNA replication
the natural process by which cells make and exact copy of a DNA molecule
PCR polymerase chain reaction
a laboratory technique used to replicate and thus amplify a specific DNA segment
a. What two types of molecules make up a chromosome?
DNA protein
b. Where are chromosomes found in a eukaryotic cell?
Nuclei
c. How many chromosomes are found in a human cell?
46
d. How many of your chromosomes come from your mother?
23
a. Describe the basic structure of the DNA molecule
double helix, twisted ladder
b. What are the four different nucleotides of DNA?
adenine, thymine, guanine. cytosine
c. Explain why the two strands are considered to be “complementary”
they will bond together, have same amount of bonds
d. If you know the sequence of nucleotides on one strand of DNA you automatically know the sequence on the other strand. Explain why.
A with T, C with G
e. What is the function of DNA in living organisms?
genetic codes
- Describe the semiconservative replication of DNA
two copies of the original DNA exist. each molecule consists of an original and a new strand
a. Describe how PCR and DNA replication are similar.
they both replicate DNA
b. Describe how PCR and DNA replication are different.
PCR happens in a test tube and only replicate certain regions
c. During PCR, what is used to separate the DNA strands to initiate replication?
heat
d. How many copies of a DNA segment can a PCR generate in a few hours?
billions
- The discovery of DNA as the genetic molecule involved several scientists. Describe the scientific contributions of the following scientists to the discovery of the structure of DNA?
a. James Watson
chemical basis of inheritance
- The discovery of DNA as the genetic molecule involved several scientists. Describe the scientific contributions of the following scientists to the discovery of the structure of DNA?
b. Francis Crick
chemical basis of inheritance
- The discovery of DNA as the genetic molecule involved several scientists. Describe the scientific contributions of the following scientists to the discovery of the structure of DNA?
c. Maurice Wilkins.
contributed to the scientific understanding of phosphorescence, isotope separation, optical microscopy and X-ray diffraction,
- The discovery of DNA as the genetic molecule involved several scientists. Describe the scientific contributions of the following scientists to the discovery of the structure of DNA?
d. Rosalind Franklin
the water loving phosphate groups of DNA must be on the outside, xray defections confirmed that the elongated form a of DNA had all the characteristics of a twisting helix
- The discovery of DNA as the genetic molecule involved several scientists. Describe the scientific contributions of the following scientists to the discovery of the structure of DNA?
e. Erwin Chargaff
base pairing
- DNA testing has helped the Innocence Project free more than 300 people from prison since 1992, including how many who served time on death row?
18
- How did Barry Bench die?
suicide, ran in front of truck
- What piece of evidence from the original case yielded mixtures of DNA, containing DNA from the victim and another person?
nightshirt
- What is the name of the scientist who developed the method known as PCR (and later won the Nobel prize for his/her work)?
Kary Mullis
homologous chromosome
a pair of chromosomes that both contain the same genes. In a diploid cell, one chromosome in the pair is inherited from the mother, the other from the father
diploid
having 2 copies of every chromosomes
haploid
having only 1 copy of every chromosome
phenotype
the visual or measurable features of an individual
genotype
the particular genetic makeup of an individual
gametes
specialized reproductive cells that carry one copy of each chromosome (haploid) sperm are male gametes eggs are female gametes
meiosis
specialized type of nuclear division that generates genetically unique haploid gametes
zygote
cell that is capable of developing into an adult organism. the zygote is formed when an egg is fertilized by a sperm
embryo
an early stage of development reached when a zygote undergoes cell division to form a multicellular structure
recombination
an event in meiosis during which maternal and paternal chromosomes pair and physically exchange DNA segments
independent assortment
the principle that alleles of different genes are distributed independently of one another during meiosis
ovaries
paired female reproductive organs, the ovaries contain eggs and produce estrogen and progesterone
oviducts
the tube connecting an ovary and the uterus in females. eggs are ovulated into and fertilized within the oviducts
uterus
the muscular organ in females in which a fetus develops
vagina
the first part of the female reproductive tract, extending up to the cervix; also known as the birth canal
cervix
the opening or neck of the uterus where sperm enter and babies exit
fertilization
the fusion of an egg and a sperm
semen
the mixture of fluid and sperm that is ejaculated from the penis
testes
paired male reproductive organs, which contain sperm and produce androgens
scrotum
the sac in which the testes are held
vas deferens
paired tubes that carry sperm from the testes to the urethra
urethra
tube that connects the bladder to the genitals and carries urine out of the body. in males the urethra travels through the penis and also carries sperm
- Give two symptoms of the genetic disease cystic fibrosis (CF).
mucus clogs airways
can’t digest well
- What is the most common fatal genetic disease in the United States?
Cystic fibrosis
a. Where does each of the chromosomes in a homologous pair come from?
one from father and one from mother
b. How many homologous pairs of chromosomes are found in human cells?
46
a. Are gametes haploid or diploid?
haploid
b. How many chromosomes are in a human gamete?
23
c. Are there homologous pairs in a gamete?
no
d. What is the gamete produced by females?
egg
e. What is the gamete produced by males?
sperm
a. When does DNA replication happen? (Before or after cell division)
before
b. How many cell divisions happen in meiosis?
2
- Compare and contrast the cell division processes of mitosis and meiosis
mitosis copies and reproduces cells from one cell to two daughter cells. meiosis takes a gamete with only 23 chromosomes and connects to another gamete. they fertilize and split into 4
- Why does recombination and independent assortment occur during meiosis (what is its function)?
recombination does so that the maternal and paternal chromosomes switch around with each other. independent assortment is that each pair of chromosomes switches separately from others (not a package deal) so that offspring will have different DNA
- Female reproductive system ((Infographic 30.1.) Be able to identify the labeled parts (ovaries, cervix, vagina, oviducts, and uterus).
ok
- Male reproductive system (Infographic 30.2). Be able to identify the labeled parts (testes, vas deferens, urethra, penis, scrotum)
ok
- What is the difference between semen and sperm?
semen is a mixture of fluids (fructose, alkaline bases) containing sperm
sperm is a cell (gamete) with only 23 chromosomes
Where in the female reproductive tract does fertilization actually occur?
oviducts (fallopian tubes)
a. How long can sperm live (remain viable) inside the female reproductive tract?
3-7 days
b. What makes a zygote into an embryo?
cell division
c. Where does embryonic and fetal development occur in the female reproductive tract (what part)?
uterus
b. What is the fundamental difference in the way fertilization happens in fish compared to humans, mammals, birds, and reptiles?
n
b. What is the fundamental difference in the way fertilization happens in fish compared to humans, mammals, birds, and reptiles?
outside of body
- What is the name of the 5-girl rock ‘n’ roll band featured in Chapter 11?
Hellen
c. Which type of cell division (meiosis or mitosis) does bacterial reproduction most resemble? Explain.
mitosis
- How many babies are born with cystic fibrosis each year?
2500
- What is the failure rate for barriers as a contraceptive method
2-21%
- What is the average cost of a single round of IVF treatment?
$12,400
recessive allele
an allele that reveals itself in the phenotype only if masking dominant allele is not present; lower case letter
dominate allele
an allele that can mask the presence of a recessive allele uppercase letter
heterozygous
having 2 different alleles
homozygous
having 2 identical alleles
Punnett square
a diagram used to determine probabilities of offspring having particular genotypes, given the genotypes of the parents
carrier
an individual who is heterozygous for a particular gene of interest, and therefore can pass on the recessive allele without showing any of its effects
law of segregation
when an organism produces gametes, the two alleles for an given trait separate so that each gamete receives only one allele. consequently, each parent donates only one of any two alleles to any offspring. the alleles don’t blend but remain as discrete pieces of information as the pass from one generation to the next
law of independent assortment
two alleles for any given trait will segregate independently from and other alleles when passed on to gametes, consequently, each gamete may acquire any possible allele combination and traits
blood
a collection of cells that circulate within a protein-rich salty fluid called plasma
erythrocytes
red blood cells, no nucleus, carries oxygen to cells and carbon dioxide away, live about 120 days constantly being replaced by new cells produced in your bone marrow
leukocytes
white blood cells, denfend the body, make up less than 1% of cells but only component that has a nucleus, attack and kill foreign cells makes antibodies to fight disease
a. For the following examples, indicate if the individual is homozygous dominant, homozygous recessive, or heterozygous: AA
homozygous dominant
a. For the following examples, indicate if the individual is homozygous dominant, homozygous recessive, or heterozygous: Aa
heterozygous
a. For the following examples, indicate if the individual is homozygous dominant, homozygous recessive, or heterozygous: aa
homozygous recessive
- Assume a genetic disorder is caused by a recessive allele (also see infographic 11.7).
a. Would a heterozygous carrier show symptoms of the disorder?
no
Assume a genetic disorder is caused by a recessive allele
b. Could this person pass the recessive allele on to his/her children?
yes
Assume a genetic disorder is caused by a recessive allele
If both parents are heterozygous carriers, what is the chance that their child will ; Not have the disorder?
75%
Assume a genetic disorder is caused by a recessive allele
If both parents are heterozygous carriers, what is the chance that their child will ; Have the disorder?
25%
- Assume a genetic trait is caused by a dominant allele (also see infographic 11.8)
a. For the following genotypes, indicate if the individual would have the trait (show the disease):
i. TT
yes
- Assume a genetic trait is caused by a dominant allele (also see infographic 11.8)
a. For the following genotypes, indicate if the individual would have the trait (show the disease):
ii. Tt
yes
- Assume a genetic trait is caused by a dominant allele (also see infographic 11.8)
a. For the following genotypes, indicate if the individual would have the trait (show the disease):
iii. tt
no
- Assume a genetic trait is caused by a dominant allele b. If both parents are heterozygous, what is the chance that their child will:
i. Have the trait?
75%
- Assume a genetic trait is caused by a dominant allele b. If both parents are heterozygous, what is the chance that their child will:
ii. Not have the trait?
25%
- What is pre-implantation genetic diagnosis (how is it done)?
by IVF you can select the embryos without defects to be implanted
- Why do some couples use pre-implantation genetic diagnosis?
so that their children won’t develop the diseases they could inherit
- Researchers have long puzzled over why the disease varies in two people with identical CF alleles. What have scientists found in recent years, dealing with genes and alleles, that helps to explain this situation?
scientists have found that other genes on different chromosome that can contribute to the severity of CF symptoms
- Inheritance of two genes (see infographic 11.9). The genotypes of both parents are AaDd.
a. List the 4 possible allele combinations that can be found in their gametes (remember: since these cells are haploid, they only contain 1 copy of each allele)
AD,Ad,aD,ad
Inheritance of two genes (see infographic 11.9). The genotypes of both parents are AaDd.
b. How many of the 16 possible offspring will have genotype AaDd?
4
Inheritance of two genes (see infographic 11.9). The genotypes of both parents are AaDd.
c. How many will be homozygous recessive for both genes?
1
MENDELS’ GARDEN
- List several traits that Mendel studied. How many forms were possible for each of these traits?
seed shape, seed color, pod shape, pod color, flower color, stem length. 2 for each
- Mendel began his experiments with plants that “bred true”. Based on what you learned in Chapter 11, would you conclude that these plants were homozygous or heterozygous?
homozygous
- Mendel crossed white-flowered plants with purple-flowered plants.
a. How did he prevent self-pollination?
removing male parts from plants
- Mendel crossed white-flowered plants with purple-flowered plants.
b. What color flower did the offspring (F1 generation) produce?
purple
- Mendel crossed white-flowered plants with purple-flowered plants.
c. Be able to explain how the recessive trait (white flowers) reappears in the F2 generation (see Infographic M4.3)
by having both recessive allele from each parent (rr)
- Be able to explain how Infographic M4.4 shows the law of independent assortment.
offspring can display any combo of the different traits. rather than inheriting traits together
FROM LECTURE NOTES
1. About how much blood does an average adult human have?
5-6 quarts
- Give two important molecules found dissolved in blood plasma.
proteins and salts
- Blood cells
a. What is special about the genetic component of erythrocytes?
no nucleus
- Blood cells
b. What is the main role of erythrocytes in the human body?
carries oxygen to cells and carbon dioxide away
- Blood cells
c. About what % of blood cells are leukocytes?
1%
- Blood cells
d. What is the main role of leukocytes in the human body?
fight infections
- What are the possible genotypes and phenotypes of the four major groups of human blood types?
AB,Ab,aB, ab
A, B, AB, O
- Who was the Punnett square named after?
Reginald C. Punnett
- Where did Mendel study math, physics, zoology, botany, and plant physiology?
University of Vienna
- What is the scientific name for the pea plant? (from photo on pg. 253)
Pisum sativum
- Type AB blood is considered to be “codominant”. What does that mean?
if your mother passes on the A allele and your father passes on the B allele, you will be genotypically “AB” and phenotypically “blood type AB”. This differs, say for example with a A and O - A is completely dominant. If a person is genotypically “AO” then they are phenotypically “blood type A”.
autosomes
paired chromosomes present in both males and females, all chromosomes except the x and y chromosomes
sex chromosomes
Paired chromosomes that differ between males and females, XX in females, XY in males
X-linked trait
a phenotype determined by an allele on an X chromosome
Incomplete Dominance
a form in inheritance in which heterozygotes have a phenotype that in intermediate between homozygous dominant and homozygous recessive
Co dominance
a form of inheritance in which both alleles contribute equally to the phenotype
contiuous variation
Variation in a population showing an unbroken range of phenotypes rather than discrete categories
polygenic trait
a trait whose phenotype is determined by the interaction among alleles of more than one gene
Multifactorial inheritance
an interaction between genes and the environment that contributes to a phenotype or trait
anueploidy
an abnormal numbner of one or more chromosomes (either extra or missing copies)
Nondisjuction
the failure of chromosomes to separate accurately during cell division; nondisjunction in meiosis lead to aneuploid gametes
Trisomy 21
carrying an extra copy of chromosome 21; also known as Down syndrome
Amniocentesis
a procedure that removes fluid surrounding the fetus to obtain and analyze fetal cells to diagnose genetic disorders
Nuclear DNA*
the DNA found in the nucleus of the cell; most used for forensic
Mitochondrial DNA*
DNA from your mother
Restriction enzymes*
isolated from certain species of bacteria; evolved as a way for bacteria to destroy the DNA of invading viruses
Karyotype
the chromosomal makeup of cells. Karyotype analysis can be used to detect trisomy 21 prenatally
- X and Y chromosomes
a. How many sex chromosomes are in an egg?
2, 1 pair (XX)
- X and Y chromosomes
b. How many are in a sperm cell?
2, 1 pair (XY)
- X and Y chromosomes
c. What determines if a baby will be a boy or a girl, the sperm or the egg (or both)?
sperm
- Why do X-linked traits affect sons with higher frequency than daughters?
a. Identify three specific X-linked disorders.
Duchenne muscular dystrophy, color blindness, hemophilia
- Why do X-linked traits affect sons with higher frequency than daughters?
b. Are the alleles that cause problems dominant or recessive?
recessive
- Why do X-linked traits affect sons with higher frequency than daughters?
c. Can a woman be color blind?
yes, rarely
- Why do X-linked traits affect sons with higher frequency than daughters?
d. Understand the inheritance pattern of X-linked recessive traits (Infographic 12.2).
recessive mutatuion on the X chromosome; affects males because they only inherit one copy of X; a single DMD allele determines their phenotype; females have two X chromosomes, may have mutation but it won’t show
- Why does the Y chromosome persist relatively unchanged from generation to generation?
Y chromosomes don’t have homologous chromosome with which to pair and exchange DNA during meiosis; rarely goes through genetic recombination
