Flashcards in B1 - Variation, Reproduction & New Technology Deck (29)
What are gametes?
How do parents pass on genetic information to their offspring?
They pass on genetic information in the sex cells.
What are chromosomes?
Thread like structure made up of DNA that carry genes.
In which part of a cell is the genetic information found?
In the nucleus.
What does DNA stand for?
What is the shape of the DNA molecule?
A double helix
What is a gene?
A sequence of nucleic acids in the DNA.
How many chromosomes does a normal human have and where from?
Humans have 46 chromosomes in 23 pairs. Half from the mother, half from the father.
What is the purpose of a gene?
Genes work at the level of the molecules in the body to control the development of characteristics by controlling different enzymes and proteins.
Why does asexual reproduction result in genetically identical offspring?
There is no joining of gametes and one parent meaning there is no variety.
What is a clone?
Genetically identical offspring of asexual reproduction.
What types of organisms reproduce asexually?
How does sexual reproduction produce variety?
Male and female gametes join so the mixture of genetic information in the parents leads to variety.
Why is genetic variety important?
Variety makes it more likely that the offspring will survive difficult conditions.
How are plants cloned?
Taking cuttings of mature plants.
What can change the characteristics of a person?
How is embryo cloning undertaken in cows?
-A top-quality cow is given fertility hormones in order to produce lots of eggs.
-The eggs are fertilised using the sperm of a decent bull.
-After growing, the embryo is removed from the womb and divided into several individual cells.
-The cells grow into identical embryos then are transferred to the host mothers.
-The mothers have been given pregnancy hormones so then the identical cloned calves are born.
How are plants cloned using tissue culture?
A mixture of plant hormones is used to make a small group of cells from the desired plant.
Give an advantage of embryo cloning.
The cow can produce more calves than by natural means.
How is adult cell cloning done?
-The nucleus is removed from an unfertilised egg.
-The nucleus is also taken from an adult body cell of another animal.
-The nucleus from the adult cell is transferred into the empty egg cell.
-A small electric shock causes the egg cell to begin to divide and starts embryo development.
-The embryo is placed in the womb of a third animal to develop.
-The animal born is genetically identical to the nucleus donor.
Give three disadvantages of adult cell cloning.
-People may abuse the technology to make cloned of themselves.
-Cloning produces genetically identical organisms, reducing variety. If there is a change in the environment, all of the animals will die because none of them contain the useful characteristic.
Give two advantages of adult cell cloning.
-Animals that have been genetically engineered to produce useful proteins in their milk can be cloned.
-Animals could be saved from extinction or bring back extinct species.
What is genetic engineering?
Changing the genetic material of an organism.
Explain how insulin is made using genetic engineering.
-Human cells are taken that contain the insulin producing genes.
-The insulin gene is "cut out" of the DNA using an enzyme.
-A plasmid is removed from a bacterium and split using an enzyme.
-The insulin gene is inserted into the plasmid using another enzyme.
-The plasmid with the insulin gene is taken by the bacterium.
-The bacterium multiplies many times therefore mass producing insulin.
How are genes transferred from one organism to another?
Genes from a chromosome are "cut out" using enzymes and inserted to the cells of bacteria and other organisms.
Give six advantages of genetic engineering.
-Specific proteins can be made.
-Exact amounts can be produced.
-The protein is very pure.
-Crops can be adapted making hunger less of an issue.
-The yield of GM food is generally greater.
-Plants can produce their own pesticide.
Give an example of how animal genes can be transferred interspecies to assist in farming.
Glowing genes from a jelly fish have been used to produce crop plants that glow when being attacked by insects.
How can genetic engineering be beneficial for people with genetic diseases?
The affected cells can have healthy genes inserted.