Flashcards in Genetic Processes Deck (147):
Smallest structural unit of matter?
Atoms bond to form what?
Molecular compounds and ionic compounds
What are molecular compounds important to biology?
What are very large, complex molecular compounds?
What is starch/amylose?
A macromolecule consisting of 1000s of glucoses bonded together
What is Protein?
A macromolecule conisting of 100s to 1000s of amino acids
What are triglycerides?
Glycerol bonded to 3 fatty acids.
What are nucleic acids?
DNA and RNA. Millions of nucleotides bonded together.
What are macromolecules that assemble into functional groupings?
Membranes are what?
A supermolecular assembly consisting of carbohydrates, phospholipids, proteins, cholesterol
Ribosomes are what?
A supermolecular assembly consisting of protein and ribosomal RNA
Microtubules and microfilaments are what?
Supermolecular assemblies, collections of protein
The nucleolus is what?
A supermolecular assembly consisting of protein and RNA
Supermolecular assemblies organize into what functional units?
A porous double membrane surrounding DNA, RNA, nucleolus
Double membrane surrounding enzymes, dna and ribosomes
Double membrane surrounding enzymes, dna and ribosomes
Single membrane surrounding digestive enzymes
Red blood cell
List tissue examples
Epithelial, connective, muscle, nerve, plant,
What are the levels of biological organization?
Subatomic particles, atom, molecular/ionic compounds, macromolecules, supermolecular assemblies, organelles, cells, tissue, organs, organ systems, organisms.
What is biology?
The study of life
What makes something "alive"
What is respiration?
Obtaining energy as a result of chemical changes, usually decomposition of food as a result of combination with oxygen. Take in oxygen, give off carbon dioxide. Usually accompanied with rise in temp.
What is excretion?
Elimination of toxic/waste substances from the body of an organism. Not the same as egestion of undigested food.
What is feeding?
Essential preliminary to respiration. Taking in food.
What is growth?
An increase in size, usually involves an organism becoming more complicated and efficient. (tadpole to frog)
What is movement?
Can be locomotion, or restricted to certain areas, like leaves in plants, or result due to growth.
What is reproduction?
Handing life on to new individuals, resulting in continued existence of species. Can be on cellular level, not always species level.
What is irritability?
Ability to respond to stimulus. More advanced the greater the range of sensitivity. Organisms seek to maintain homeostasis. Flight or fight response, ex.
What are the types of nucleic acids?
Chromosomes are what?
Made up of DNA that is genetic material. Contain codes to make proteins for your body.
What is RNA?
Translates DNA nucleotide codes and instruction the ribosomes how to assemble amino acids into proteins for your body
What is a gene?
A segment of DNA that provides the blueprint for making one protein
Atomic level, nucleic acids are made of what?
Phosphorus, nitrogen, carbon, hydrogen, oxygen
Higher level, nucleic acids are made of what?
They are polymers made up of monomers. Made up of nucleotide chains. Are polymers of nucleotides.
What is a nucleotide made of?
A pentose sugar, a phosphate group, and a nitrogen containing base
What are the pentose sugars in DNA and RNA?
Deoxyribose and Ribose
What are phosphodiester linkages?
The linkages that hold the nucleotides in RNA and DNA together. These linkages are formed between carbon 3 of the sugar and a phosphate group that is associated with carbon 5 of the sugar.
The backbone of DNA is what?
Alternating sugars and phosphates. Double stranded.
How are polymer chains held together in DNA?
Hydrogen bonding between their nitrogen bases.
How is base pairing complementary?
Each position with a purine is found on one strand a pyrimidine is found on the other
What is a purine?
Have a double ring structure
what is a pyrimidine?
Have one ring.
How are DNA strands arranged?
They are antiparallel (one side is flipped). Strands form a double helix with a right handed twist.
What is another name for a tri-nucleotide?
What is the cell cycle?
2 stages: growth and division
Why do cells divide when they grow?
The surface area to volume ratio goes down.
How do new cells compare to divided ones?
What is mitosis?
Division of nuclear material so each daughter cell receives the same number of chromosomes.
What is cytokinesis?
The division of cell organelles and cytoplasm
When are chromosomes visible?
Why is cell division needed?
Growth of organism
Regeneration of lost or damaged tissues
Maitenance of body
What are the stages of mitosis?
prophase, metaphase, anaphase, telophase
What happens in interphase?
-G1: normal functions, growth
-Synthesis: replicated DNA molecules visible as chromatin, centrioles split and become 2 centrosomes
-G2: additional organelles, more growth
What happens in prophase?
-longest phase of mitosis
Early: chromatin condenses into visible chromosomes (sister chromatids), centrosomes move to opposite poles,
Late: nuclear membrane disappears, nucleolus disappears, centrosomes begin producing spindle fibres, chromosomes begin moving to equator
What happens in Metaphase?
-sister chromatids move to equator and align themselves randomly. nuclear membrane gone. (end of prophase)
What happens in anaphase?
-spindle fibres contract and shorten
-centromeres split apart
-sister chromatids become daughter chromosomes
-move to opposite poles
What happens in telophase?
-chromosomes reach poles
-spindle fibres break down
-nuclear membrane and nucleolus begin to reform
What happens in cytokinesis (plants specifically?)
Cleavage furrow forms as membrane constricts.
Plants: vesicles travel to equator and fuse together, form cell plate which becomes two cell walls
What are some special cases regarding mitosis?
Cancer cells which divide unchecked, specialized cells like muscle and nerve that don't divide
What is malignant cancer cells that migrate?
What is meiosis?
Form of cell division where gametes with half the amount of DNA are produced
Diploid (2n) to haploid (n)
Where does meiosis occur?
Gonads (testes or ovaries)
What is the production of gametes in males and females?
Spermatogenesis and oogenesis
What are the cells called that undergo meiosis in males and females?
Spermatogonium and oogonium
What is interphase 1 of meiosis?
Same as mitosis
What are the phases of meiosis?
Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II
What happens in prophase I
-longest and most complex (90%)
-many the same (centrosomes, spindles, nucleolus and nucleus, condense)
-synapsis: -form bivalent, then tetrad
-pairs brought to centre
How many pairs in a DNA?
How many genes human genome?
List the three foundational statements of the cell theory
-to be living must contain one or more cells
-cells are the smallest form of living organisms
-cells can only come from pre-existing cells through reproduction
How would lack of spindle fibres affect mitosis?
Would inhibit or make impossible because the sister chromatids would not be pulled apart and there would be random division in cytokinesis.
What is an allele?
Different forms of the same gene
How are karyotypes prepared?
-cells are obtained then treated so they are stopped during metaphase
-a stain makes the banding patterns on the chromosomes clearly visible
-paired and sorted longest to sex
-autosomes numbered 1-22
-sex chromosomes labeled x or y
How are chromosome pairs recognized?
-preforms normal operations. Excludes reproductive cells
How long does the cell cycle take?
Usually 12-24 hours
How is DNA semi-conservative replicated?
1. Protein unwinds the double helix into a ladder. They then unzip the DNA by breaking the hydrogen bonds in the base pairs
2. Complimentary base pairing. Enzymes travel along polynucleotide strands and attach complementary nucleotides, A-T G-C G-C T-A
3. Enzymes travel along polynucleotide strands and create the phosphodiester linkages
What are homologous chromosomes?
Same size, banding pattern, and centromere location. Contain alleles.
Homologous chromosomes that come together in prophase but aren't completely wound yet
Two homologous chromosomes side by side with 4 visible chromatids
How do chromatids compare in a tetrad?
Joined by centromere: Sister
Not joined: Non sister
Define allele and locus
Locus: position on gene. Allele is gene in certain position carrying same type of info in two homologous chromosomes.
What is crossing over and how does it happen?
-Exchange of DNA between non sister chromatids at the chiasma (pl. chiasmata) (The complete "X". Specific site called the cross-over point)
-highly variable and random
What happens in metaphase 1?
Tetrads align on the equatorial plate
independent assortment occurs
What is independent assortment?
-random arranging of pairs in metaphase
-formula is 2^n
What is Anaphase 1?
Homolgous chromosomes separate and move toward poles. Sister chromatids remain attached at centromere
What happens in Teleophase 1?
Chromosomes reach the opposite poles. Each pole has haploid set. Spindle fibres begin to break down. Nuclear membrane begins to reform. Nucleolus reappears. Chromosomes uncoil.
What happens in cytokinesis 1?
Membrane pulled inwards and organelles divided to create genetically different haploid daughters.
How does Meisosis 2 compare with 1?
-almost no interphase 2
-all the same, just 23 chromosomes organized in 2 cells
-cytokinesis produces 4 genetically different haploid daughter cells called gametes
Why is genetic variation good?
-important to population as raw material for natural selection
-increased genetic variability increases chances of survival
What are the sexual 3 sources of genetic variation?
1. Crossing over
2. Independent assortment
3. Random fertization
What is fertization?
-the fusion of a sperm and egg to form a zygote
What is a zygote?
-a fertized egg
Application of science and engineering to the direct or indirect use of living organisms (or parts or products) in their natural or modified forms.
What are historic uses of biotechnology?
6000 BC Yeast used by Sumerians and Babylonians to make beer
4000 BC Egyptians discovered how to make bread using yeast. China learned how to make yogurt and moulds to produce cheese and fermentation to make vinegar and wine
2000 BC Domestication of plants and animals
What is selective breeding?
The process of artificial manipulation of a species by humans to produce offspring with some desired characteristics.
Biotechnology has what general uses?
-understanding inheritance and gene expression
-understand and treat genetic disorders
-forensics and crime investigations (DNA fingerprinting)
What industrial applications of biotechnology?
1. Medial and health care
2. Food and crop production (beer, cheese)
3. Non food uses of crops (Biofuels)
4. Enviromental uses (bioremediation, treating waste)
What are the applications of biotechnology in health care?
1. Human Genome Project
2. Genetic Engineering
3. Reproductive technology
What is the Human Genome Project?
-started 1990 to 2003
-publicly funded by universities and government agencies around world
-mapped out 23 000 protein coding genes in our genome
What is genetic engineering?
A form of biotechnology used to produce molecules of DNA containing new genes or novel combinations of genes, usually for insertion into a host cell for cloning.
-genetically modified organism
What is recombinant DNA?
DNA formed by combining segments of DNA from two different sources
What is gene splicing?
Cutting DNA of a gene to add base pairs (done chemically)
How is recombinant DNA formed?
1. Identify individual genes of interest
2. Produce a copy of the gene (often using bacteria)
3. Insert the gene into the desired organism and regulate the expression of the gene in a useful way
What are desirable uses of Recombinant DNA technology?
1. Insulin injected into bacteria
2. Producing safe and effective vaccines
3. Increasing milk production
4. Hemophiliacs can get blood clotting stuff from bacteria
What is gene therapy and what are the two types?
Replacing defective genes with healthy genes
1. Somatic cell therapy
2. Germ-line Cell therapy
What are stem cells?
Cells that are not yet specialized to perform a particular function. They have the potential to differentiate into any cell.
What are the fates of a stem cell?
1. divide repeatedly and create more
2. differentiate to produce cells needed for tissue growth and repair.
What are the types of stem cells?
Adult multipotent stem cells
Embryonic stem cells
What are Adult multipotent stem cells?
-present in humans throughout life
-replace lost or damaged tissue
-limited plasticity (certain tissues)
-located in bone marrow, intestine, and nose
What are embryonic stem cells?
-found in embryo blastocyst (hollow ball of cells) 4-5 days after fertilization
-are completely plastic
What are stem cells controversial?
-only found in human embryos
-to harvest you must destroy the embryo
-debate as to where life begins
What is the problem with stem cells?
They are more susceptible to cancer and other diseases.
What are potential uses of stem cells?
-spinal cord injuries
What are clones?
Any organism whose genetic information is identical to that of a parent organism from which it was created.
What was the first thing to be cloned?
Tadpoles in 1952
Who was Dolly?
-first mammal successfully cloned in 1996
-one out of 277 attempts
What are current cloning projects?
-endangered mountain sheep (2001)
-other endangered or recently extinct animals
-genetically modified pigs for human organ donation
What are the risks of cloning?
90-95% of attempts fail
-clones that do survive are often in poor health and die of mysterious causes
-up to 4% of genes in cloned mice do not function properly
What are genetically modified organisms?
An organism whose genetic material has been altered using genetic engineering techniques.
What is recombinant DNA technology?
Uses DNA from different sources, which are combined into one molecule to create a new set of genes
What are transgenic animals?
An organism formed by the insertion of foreign genetic material into the cells of organisms. DNA is removed from a donor organism and foreign DNA fragments are inserted into the nucleus of a fertilized egg.
What are examples of reproductive technology?
-in vitro insemination
How does biotechnology improve plant breeding?
-tolerance of harsh conditions
What are the two key outcomes of meiosis?
1. Genetic reduction (make a haploid)
2. Genetic recombination (different combinations of alleles. Increases genetic variation
What are some errors in chromosome structure possible?
What is non-disjunction?
failure of homologous chromosomes or sister chromatids to separate during meiosis.Can occur in anaphase 1 or 2
What are trisomies and monosomies?
Tri: Loss of a chromosome due to non-disjunction
Mon: Gain of chromosome
Most result in death, some lead to genetic disorders like downsyndrome
What is prenatal genetic testing?
Tests performed on a fetus to look for genetic based abnormalities.
Initially involve blood tests and ultrasound. Also maternal blood tests and invasive tests (amniocentesis and chorionic villus sampling)
What are the differences between spermatogenesis and oogenesis?
-4 viable sperm cells
-both produce haploid cells
-1 egg cell
-cytoplasm unequally divided, one polar body
What is artificial insemination?
Sperm are collected and concentrated before being artificially introduced into the female reproductive system. Typically the semen is stored for a period of time. Makes high quality semen readily available.
What is Embryo transfer?
An egg that has been fertilized artificially is transferred into a recipient female's uterus.
What is invitro fertilization?
-eggs are combined with sperm in laboratory glassware then placed in uterus of mother
-helps couples who cannot conceive on their own
What is preimplantation genetic diagnosis?
-allows for diagnosis of genetic disorders soon after fertilization. IVF used. Zygotes allowed to develp for 2 days then tested
Also used to engineer a genetic match in a sibling for sick children.
How is gene cloning done?
1. Isolate segment of DNA to clone, choose a vector. Vectors act as carriers of the DNA to be cloned so that the DNA can be copied in a foreign cell. Usually a plasmid in a bacteria. (Small, circular pieces of DNA)
2. Insert the chromosomal DNA into the vector. Relies on use of reagents that can cut DNA and help different pieces join together. Resulting DNA is callled recombinant DNA
3. Treat foriegn cells, usually bacteria, so they take up the recombinant DNA. Once inserted many copies will be made by the host cell
What is therapeutic cloning vs. reproductive?
T: Produces genetically identical cells to treat diseases
R: Produce a genetically identical organism
Both use somatic cell nuclear transfer
What is somatic cell nuclear transfer?
1. Cells obtained
2. Nucleus removed from egg cell removed, nucleus with desired genes is obtained
3. Nucleus fused with donor egg
4. Cells are cloned