chapter 11 Flashcards
What is embryo cloning?
Splitting cells apart from a developing embryo to produce several identical embryos.
This process occurs before the cells become specialized.
What is nuclear transfer?
Transferring a body cell into an egg and then stimulating cell division to produce an embryo.
This technique allows for the creation of clones from differentiated cells.
What are cuttings in the context of cloning?
Taking a small piece of stem and growing it in the right conditions to produce a new plant.
This method is commonly used in horticulture.
What is tissue cloning?
Getting a few cells from a desirable plant to make a big mass of identical cells, each of which can produce a tiny identical plant.
This technique allows for mass production of genetically identical plants.
What is asexual reproduction?
Reproduction that involves only one parent, resulting in offspring that are genetically identical to the parent.
This is a natural method of cloning.
Who was the first vertebrate clone?
A frog.
The nucleus of a body cell was taken from an adult frog and placed in an egg cell.
Who was the first cloned mammal?
Dolly the sheep.
Dolly was born at the Roslin Institute in Edinburgh in 1996.
How was Dolly the sheep cloned?
A cell from the donor animal was taken from a mammary gland and put in the egg of another sheep, which was then placed into a surrogate mother.
This process demonstrated that a cell from a specific part of the body could recreate a whole individual.
What are some benefits of cloning?
- Providing new babies for infertile couples
- Producing new organs for transplant that won’t be rejected
- Helping ensure the survival of endangered species
- Bringing back extinct animals
- Producing useful proteins in milk to treat diseases
- Producing medically useful animals
- Producing prize agricultural animals
- Pet cloning
These benefits highlight the potential applications of cloning in various fields.
What are potential problems associated with cloning?
- Many embryos were miscarried before Dolly was produced
- A large number of embryos are destroyed in this technology
- Religious or ethical beliefs state that it is wrong to interfere with nature
- Many believe it is wrong to destroy or tamper with embryos
- The method reduces genetic variation
These concerns highlight the ethical and practical challenges of cloning.
True or False: Many embryos are destroyed in cloning technology.
True.
This raises ethical concerns about the treatment of embryos in the cloning process.
What is the ethical concern regarding the reduction of genetic variation in cloning?
The method reduces genetic variation, which can impact the resilience of populations.
Genetic diversity is crucial for the adaptability and survival of species.
What does genetic modification involve?
The transfer of a gene from one organism into another
How are genes removed and inserted in genetic modification?
Using special enzymes
What is a vector in the context of genetic modification?
A means to transfer genes from one organism to another
What are plasmids?
Small circles of DNA found in bacteria
Why are plasmids used as vectors?
They can easily be removed from bacteria
What is the first step in the process of inserting the insulin gene?
Removing the insulin gene from human DNA using a restriction enzyme
What is done to the plasmid DNA to prepare it for the insulin gene?
A piece of DNA is removed using the same restriction enzyme
What enzyme is used to join the insulin gene to the plasmid?
DNA ligase enzyme
What is the role of the plasmid in this process?
It serves as the vector that puts the insulin gene into the bacterium
What happens to the recombinant plasmids and bacteria after incubation?
They reproduce in a fermenter
What is the final product obtained from the bacteria containing the insulin gene?
Insulin, which is extracted and purified for diabetes treatment
Fill in the blank: The insulin gene is inserted into a _______.
plasmid
True or False: The recombinant plasmids are incubated separately from the bacteria.
False
What is diabetes?
A condition in which the body cannot control blood sugar.
What hormone is released from the pancreas after a meal?
Insulin
What is the function of insulin?
Instructs cells to convert glucose to the storage molecule glycogen.
What happens to blood sugar levels in people with diabetes?
Their blood sugar remains high.
How do people with diabetes manage their blood sugar levels?
They must inject insulin.
Why was traditional insulin production from livestock not ideal?
Animal insulin is not exactly the same as human insulin and requires many animals for small quantities.
What technology allows for the production of human insulin in large quantities?
Biotechnology
What is a host bacterium?
A bacterium which can be modified by adding genes using a vector.
What are sticky ends in DNA?
Exposed unpaired bases resulting from a staggered cut made by a restriction enzyme.
What is the role of restriction enzymes?
They cut DNA at particular sequences leaving ‘sticky ends’.
What is DNA ligase?
An enzyme that can connect pieces of DNA together.
What is a plasmid?
An independently replicating circle of DNA containing a few genes.
What is the purpose of plasmids in genetic engineering?
They can be used to carry genes into a suitable host bacterium.
Fill in the blank: __________ are enzymes found in bacteria that cut DNA at particular sequences.
[restriction enzymes]
Fill in the blank: __________ is an enzyme that can connect pieces of DNA together.
[DNA ligase]
True or False: Sticky ends are formed when DNA is cut by restriction enzymes.
True
What is the primary goal of genetically engineered bacteria in this context?
To produce human insulin.
What is a significant issue faced in many parts of the world regarding diet?
Water shortages and droughts, outbreaks of crop pests, and poor food storage
These factors can lead to difficulty in accessing a balanced diet.
What does genetic modification provide in terms of food security?
The opportunity to insert genes that add extra nutrients to plants
This is particularly relevant in less economically developed countries (LEDCs).
Which crop is primarily affected by nutrient deficiencies in LEDCs?
Rice
Rice is the main food source in many LEDCs.
What are the consequences of iron and vitamin A deficiencies?
High death rates and illness in mothers and children
These deficiencies are particularly severe in regions reliant on rice.
How can genetic modification of rice help combat nutrient deficiencies?
By increasing the availability of vitamin A and iron
Genetically modified rice can help reduce deficiency-related diseases.
What have researchers succeeded in doing with rice?
Genetically modifying rice to enhance its vitamin A and iron content
This aims to improve nutritional value for communities.
What is the plan for the new varieties of genetically modified rice?
To make them freely available to local rice farmers for planting
This approach supports local agricultural practices.
What are stem cells used for in the body?
To replace worn out or faulty cells
For how long has stem-cell technology been used in bone-marrow transplants?
More than 20 years
What happens to stem cells if a bone-marrow transplant is successful?
They migrate into the patient’s bone marrow and begin producing new, healthy blood cells
How many specific cell types can stem cells differentiate into?
Over 200 specific cell types
What medical issues is stem-cell research seen as holding the key to?
Spinal-cord injury, stroke, burns, heart disease, diabetes, arthritis
True or False: Research using stem cells is uncontroversial.
False
What moral and ethical issues are raised by stem-cell research?
Questions regarding ‘meddling with nature’ and the implications of new technologies
Which type of stem cells is currently seen as holding the best potential for research?
Embryonic stem cells
Fill in the blank: Embryonic stem cells can differentiate into _______ cell types.
all
What happens to embryos when stem cells are removed for research?
The process will destroy the embryo
What is a common argument against the use of embryonic stem cells?
Under natural conditions, the embryos would go on to form a baby
What do proponents of embryonic stem-cell research argue about unused harvested embryos?
They would anyway be destroyed
What phrase is used to describe the view that the outcomes justify the means in stem-cell research?
The ends justify the means
What is 3D-tissue and organ printing?
A novel way of utilizing stem cells to revolutionize surgery and replace faulty organs
What is the purpose of 3D-bioprinting?
To address the need for tissues and organs suitable for transplantation
How do bioprinters deliver cells in the bioprinting process?
Using inkjet needles to deliver cells, a sticky polymer, and pressurized air
What is the role of the small electric field in bioprinting?
To convert the mixture into superfine threads with cells trapped inside
Why is bioprinting more complex than non-biological printing?
It involves correct cell selection, materials, growth factors, and technical challenges with living cells
What fields of study are combined in 3D-bioprinting?
- Engineering
- Biomaterials science
- Cell biology
- Physics
- Medicine
What types of tissues have been made and transplanted using 3D-bioprinting?
- Skin
- Bone
- Heart tissue
What is a ‘bioink’ in the context of bioprinting?
A mixture of stem cells in a growth medium that can be used in the bioprinting process
What components make up a bioprinter cartridge?
A chamber attached to a long extrusion nozzle fitted with a syringe
What does the software in a bioprinter do?
Lays down stem cells in precise patterns
What material is interspersed with the cells during the bioprinting process?
Hydrogel, which forms a temporary mould around the cells
What is the function of sticky polymers in bioprinting?
To form a scaffold for cells
What happens to the printed tissue after bioprinting?
It is left to grow and can be used in transplants or medical research
