Unit 2 Flashcards
heredity (p. 138)
the passing of traits from parents to offspring
genetics (p. 138)
variation of inherited characteristics
deoxyribonucleic acid (DNA) (p. 138)
carries genetic information in cells
gene (p. 138)
DNA molecule that codes for a particular trait; found on a chromosome
locus (p. 138
the location of a gene on a chromosome
polyploid (p. 139)
having more than two sets of chromosomes
asexual reproduction (p. 139)
the production of offspring from a single parent; the genetic makeup of the offspring is identical to that of the parent
sexual reproduction (p. 140)
the production of offspring from the fusion of two sex cells (usually from two different parents); the genetic makeup of the offspring is different from that of either parent
fragmentation (p. 143)
a method of asexual reproduction in which body fragment of the parent organism develops into a mature individual
mitosis (p. 143)
eukaryotic cell divides the genetic material in its nucleus into two new identical nuclei
interphase (p. 143)
when the genetic material (in the form of chromatin) is duplicated
chromatin (p. 143)
the tangled strands of DNA and protein within a eukaryotic nucleus
sister chromatid (p. 143)
the identical copy of a single chromosome that remains attached to the original chromosome at the centromere
cytokinesis (p. 145)
eukaryotic cell divides its cytoplasm into two new daughter cells
cloning (p. 146)
the process of producing one individual that is genetically identical to another, using a single cell or tissue
biotechnology (p. 146)
the use and modification of organisms for applications in engineering, industry, and medicine
genetically modified organism (p. 148)
an organism in which the genetic material has been altered using genetic engineering techniques
gamete (p. 152)
a sex cell
fertilization (p. 152)
the formation of a zygote by the joining together to two gametes
zygote (p. 152)
a cell produced by the fusion of two gametes
ova (p. 152)
female sex cells (egg cells)
meiosis (p. 153)
a two-stage cell divisionin which the resulting daughter cells have half the number of chromosomes as the parent cell; results in the formation of gametes or spores
homologous chromosomes (p. 153)
matching pairs of chromosomes, similar in size and carrying information for the same genes.
tetrad (p. 154)
a pair of homologous chromosomes, each with two sister chromatids
synapsis (p. 154)
the physical pairing up of homologous chromosomes during prophase I of meiosis
crossing over (p. 154)
the exchange of chromosome segments between homologous pairs during synapsis
gametogenesis (p. 157)
the production of gametes (sex cells) in animals
spermatogenesis (p. 157)
the production of mature sperm cells
oogenesis (p. 157)
the production of mature egg cells
karyotype (p. 158)
the chromosomes of an individual that have been sorted and arranged according to size and type
sex chromosomes (p. 158)
chromosomes that differ in males and females of the same species; the combination of sex chromosomes determines the sex of the offspring
autosomes (p. 159)
non-sex chromosomes
non-disjunction (p. 161)
the failure of homologous chromosomes to move to opposite poles of the cell during meiosis; results in an abnormal number of chromosomes in the daughter cells
trisomy (p. 161)
a chromosomal abnormality in which there are three homologous chromosomes in place of a homologous pair
monosomy (p. 161)
a chromosomal abnormality in which there is a single chromosome in place of a homologous pair
Down syndrome (p. 162)
a chromosomal abnormality in which an individual has three copies of chromosome number 21; also referred to as trisomy 21
prenatal testing (p. 163)
testing for a genetic order that occurs prior to birth
maternal inheritance (p. 167)
a type of inheritance in which a zygote formed from
two gametes inherits cytoplasmic DNA from only the female gamete
paternal inheritance (p. 168)
a type of inheritance in which a zygote formed from two gametes inherits cytoplasmic DNA from only the male gamete
horizontal gene transfer (p. 170)
the transfer of genetic information from one species into a different species
Cell Division Patterns (Somatic Cells / Body Cells)
interphase → mitosis karyokinesis → cytokinesis …. REPEAT (start with 46 end with 46)
Cell Division Patterns (Reproductive Cells / Germ Cells)
interphase → meiosis I → cytokinesis I → meiosis II → cytokinesis II (start with 46 end with 23)
Interphase
● chromosomes/DNA replicate, condense
(i.e. DNA wraps tightly around histone proteins)
Mitosis (PMAT)
● occurs in all somatic / body cells
● produces 2 genetically identical diploid nuclei
Cytokinesis
division of cytoplasm and organelles
Prophase
● asters (centriole & spindle fibre) move to the poles- forming the mitotic spindle
● nuclear membrane dissolves
● chromosomes shorten and thicken
Metaphase (Karyotype Stage)
● sister chromatids align in the middle
● spindle fibres from opposite poles attach to each sister chromatid at the kinetochore
Anaphase
● sister chromatids separate → now called chromosomes
●sister chromatids pulled to opposite poles
Telophase
● nuclear membrane appears around each new chromosome set creating two identical nuclei
●NM reappears
●spindles disappear
● cell membrane pinches in at cleavage furrow
● chromosomes “loosen” again becoming chromatin
What are 2 types of natural clones/copies?
● single cell bacteria
● identical twins (kind of)
What are 2 types of genetically designed clones/copies?
○ i.e. plants that make insulin
○ i.e. animals that make spider silk
Gene Cloning
■ plasmids with gene inserts placed into bacteria and yeast cells (factories!)
■ proteins made en masse by all the bacteria / yeast with the inserted gene
■ drugs / proteins made for human use
● Insulin is produced by bacteria & yeast (drug for diabetics)
● Insulin can produced by safflower plant seeds that have the insulin gene inserted into their genome (they are like factories)
Therapeutic Cloning
■ enucleated egg cell + somatic nucleus of organism you LOVE → grow tissue in a petri dish
■ use for transplant and / or drug tests
● expts to understand disease & test new drugs
Reproductive Cloning
■ enucleated egg cell + somatic nucleus of organism you LOVE → insert embryo in a uterus
■ grow a “full grown” clone! (sheep/Dolly, cow, goat, etc.)
○ make clones
○ make $$
What are some ethical issues with cloning?
● An increase in abortions and miscarriages.
● Deformed embryos and clones.
● Parenting a clone.
● Clones becoming self-sufficient.
● Unknown personality of the clone.
● Rights for the clone.
● Pet cloning vs. unwanted animals & exploitation of grief
Sexual Reproduction
● sexual reproduction unites two haploid (n) gametes → generating genetic diveristy
● a gonochoric species has a male organism and female organism that produce gametes
● gametes can unite via internal fertilization or external fertilization
Gametogenesis
● haploid gametes have one of each homologue
● haploid gametes therefore carry one copy of every gene (gene = allele + allele)
● fertilization creates diploid zygotes with ….
○ 2 copies of every gene (one on each homologue)
Interphase
●DNA replication
●chromosomes become sister chromatids
Meiosis I
The Reduction Phase
Prophase I
● asters (centriole & spindle fibre) move to the poles- forming the mitotic spindle
● nuclear membrane dissolves
● chromosomes shorten and thicken
(sister chromatids,centromeres)
● synapsis forming tetrads
● crossing over
Metaphase I (Random Assortment creates genetic variation)
● alignment in the middle
● spindle fibers from opposite poles attach at the kinetochore
● replicated homologues align in the middle (tetrads)
●random assortment (2n)
Anaphase I
●replicated homologous pairs move to opposite poles
Telophase I
nuclear membrane around two “piles” of chromosomes
Cytokinesis I
● cytoplasm and organelles are divided
●two haploid cells with replicated chromosomes
Prophase II
● asters (centriole & spindle fibre) move to the poles- forming the mitotic spindle
● nuclear membrane dissolves
● chromosomes shorten and thicken (sister chromatids,centromeres)
Metaphase II
● alignment in the middle
● spindle fibres from opposite poles attach at the kinetochore
Anaphase II
● sister chromatids separate
Telophase II
● nuclear membrane around two “piles” of chromosomes
Cytokinesis II
● cytoplasm & organelles divide
● 4 genetically unique haploid cells
Spermatogenesis
Male Reproductive System
● reproductive cells (2n) are in seminiferous tubules
● reproductive cells (2n) are called spermatogonia
Oogenesis
Female Reproductive System
● reproductive cells (2n) are in the ovaries
● reproductive cells (2n) are called oogonia
What is NonDisjunction?
nondisjunction means a failure to separate
Where can NonDisjunction happen in meiosis?
○ anaphase I- replicated homologous chromosomes / tetrads fail to separate
○ anaphase II- replicated chromosomes / sister chromatids fail to separate
What are some causes of NonDisjunction?
maternal age
lifestyle
Artificial Reproductive Technologies
Gametes with Aneuploidies
Dom/ rec
Rr
Inc dom
BB(1)
Co dom
I(A) I(B)
Sex linked
XX or Xy (nothing on y)
nuclein (p. 228)
The original name given to DNA. it was discovered in the nucleus of cells by Friedrich Miescher in 1869
nucleotide (p. 229)
The repeating unit in DNA. it comprises a deoxyribose sugar, a phosphate group, and one of the four nitrogenous bases
X-ray crystallography (p. 230)
A technique in which a pure substance is subjected to X-rays. X-rays bend and spread helps reveal the structure of the pure substance
scientific model (p. 230)
a simplified representation of a concept. This can be tangible or conceptual
complementary base pairing (p. 231)
pairing of the nitrogenous base of one strand of DNA with the nitrogenous base of another strand. adenine (A.) pairs with thymine (T), and guanine (G) pairs with cytosine ©
point mutation (p. 234)
a small-scale change in the nitrogenous base sequence of a DNA. The mutation may be beneficial, harmful, or neutral (having no effect on the organism)
chromosome mutation (p. 234)
an error that involves an entire chromosome or a large part of a chromosome
spontaneous mutation (p. 236)
a mutation that is not caused by any outside factors. it occurs randomly
induced mutation (p. 236)
a mutation that occurs because of exposure to an outside factor. Such as second-hand smoke increases the chance of developing lung cancer
antibiotic resistant (p. 237)
describes strains of bacteria that are no longer susceptible to the effects of antibiotics. These are sometimes called “superbugs” and are prevalent in hospital settings
transposon (p. 237)
a specific segment of DNA that can move along or between the chromosomes
transposition (p. 237)
the process of moving a gene sequence from one part of the chromosome to another part of the chromosome
microarray (p. 238)
a small membrane or glass slide that has been coated in a predictable and organized manner with a genomic sequence
Human Genome Project (HGP) (p. 240)
a collaborative worldwide project to sequence the nitrogenous bases in human DNA
human genome (p. 240)
the sequence of DNA nitrogenous bases found on the 23 sets of chromosomes in humans
coding DNA (p. 240)
a region of DNA that contains a sequence of nucleotides that will be expressed; a gene
non-coding DNA (p. 240)
a region of DNA that does not contain a sequence of nucleotides that will be expressed
functional genomics (p. 241)
the study of the relationship between genes and their function
model organism (p. 241)
an organism that can be used to study biological functions of another organism, due to its genetic similarity
DNA bank (p. 242)
a database of DNA sequences; the sequences can be from plants, animals, or humans
DNA fingerprinting (p. 243)
a pattern of bands on a gel that is unique to each individual
restriction enzyme (p. 245)
a molecule that has the ability to cut DNA at a specific site; different restriction enzymes recognize and cut different sites
recombinant DNA (p. 245)
fragments of DNA consisting of nucleotide sequences from at least two different sources
gene therapy (p. 249)
the process by which defective genes in a genome are corrected with a normal copy of the gene
target cell (p. 249)
one of the cells that contain the faulty gene to be corrected
vector (p. 249)
any agent, such as a plasmid or a virus, capable of inserting a piece of foreign DNA into a cell
What is Lactose tolerance?
Able to consume as much dairy without side effects
What is Lactose intolerance?
Unable to consume dairy without side effects
Insertion
(add a letter)
Deletion
(subtract a letter)
Duplication
(duplicate a letter)
Invitation
(switch around)
Nature vs. Nurture Debate (Triplet Study)
● 3 boys placed in different homes - no clue triplets
● multiyear study by child psychiatrist - examining the question of “nature vs. nurture,” - never published, and the study’s materials are being kept at Yale University.
Nature vs. Nurture Debate (Mother Rats)
Those who mothers were lickers child become lickers and those who were not became non lickers
Nature vs. Nurture Debate (FAS)
Is a disorder that happens when the mother drinks alcohol while pregnant.
Nature vs. Nurture Debate (WWII testing)
● 3000 twin sets - 200 survived
● Eugenics is the scientifically erroneous and immoral theory of “racial improvement” and “planned breeding” – believed that they could perfect human beings through genetics and heredity
Down syndrome
trisomy of chromosome 21
Edward syndrome
trisomy of chromosome 18
Klinefelter syndrome
two X and one Y sex chromosomes
Turner syndrome
one X and no Y sex chromosome
Patau syndrome
trisomy of chromosome 13
Chargaff’s rule
• The amount of adenine (A.) is always equal to the amount of thymine (T).
• The amount of guanine (G) is always equal to the amount of cytosine (C).
Genetic disorders: Huntington’s
Huntington’s disease when it stops parts of the brain working properly over time. It’s passed on from a person’s parents.
Genetic disorders: Sickle cell Anemia
It affects the shape of red blood cells, which carry oxygen to all parts of the body.
Genetic disorders: Colored vision
This means you cannot see color
Genetic disorders: hemophilia
usually an inherited bleeding disorder in which the blood does not clot properly
What are the 5 steps to Gene cloning?
1.Isolation of donor DNA fragment or gene.
2.Selection of suitable vector.
3.Incorporation of donor DNA fragment into the vector.
4,Transformation of recombinant vector into a suitable host cell.
5.Isolation of recombinant host cell
Scientists and contributions: Watson and Crick
discovered the double-helix structure of DNA
Scientists and contributions: Chargaff
found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal.
Scientists and contributions: Gladwell
Canadian journalist
Scientists and contributions: Suzuki
Was a gentiet in Vancouver
Scientists and contributions: Paabo
Nobel Prize in Physiology & Medicine
Scientists and contributions: Mendel
discovered the fundamental laws of inheritance.
GMO: Bt corn
Bt corn is enhanced through biotechnology to protect against insect
GMO: pesticide resistant crops
Allow no pesticides
GMO: insulin producing bacteria
GMO insulin is also known as synthetic insulin, or human insulin. It is produced with genetically modified bacteria, instead of the traditional method that produces what is known as pork insulin. In this method, sometimes called natural insulin, the pancreas of a cow or pig is used to produce insulin.
GMO: antifreeze genes in plants
inhibit the growth and recrystallization of ice that forms in intercellular spaces.
3 steps to Gene therapy
Replacing a mutated gene that causes disease with a healthy copy of the gene
- Inactivating, or “knocking out,” a mutated gene that is functioning improperly
- Introducing a new gene into the body to help fight a disease
Law of segregation
When an organism makes gametes, each gamete receives just one gene copy, which is selected randomly.
Law of independent assortment
the alleles of two (or more) different genes get sorted into gametes independently of one another. In other words, the allele a gamete receives for one gene does not influence the allele received for another gene.
IVF (process, purpose, uses)
- mature eggs are collected (retrieved) from ovaries and fertilized by sperm in a lab. Then the fertilized egg (embryo) or eggs (embryos) are transferred to a uterus.
- to help with fertility
- to help a woman become pregnant
recombinant dna
scientists can easily add genes from one species into bacteria to produce a product. For example, insulin is regularly produced by means of recombinant DNA within bacteria. A human insulin gene is introduced into a plasmid, which is then introduced to a bacterial cell.
What are gene therapy obstacles?
Unwanted immune system reaction.
Targeting the wrong cells. .
Infection caused by the virus. .
Possibility of causing a tumor.
Types of DNA Banks
○ personal / private
○ endangered species
○ police forces / RCMP
Why might you sequence DNA?
● legal issues
○ illustrate innocence or guilt
○ look for serial offenders
● paternity suits
● determine ancestry
● predict genetic disorders
● identify remains
● supermarket labels
Day 5
