Genes and Cloning Flashcards
Where are genes carried?
Chromosomes in the nucleus
What does sexual reproduction produce?
Offspring that resemble their parents but are not identical to them.
Why do offspring resemble their parents?
They contain genetic information passed onto them by their parents.
Where chromosomes found?
In the cell nucleus.
What are found in chromosomes?
Many genes.
What is a gene?
A section of DNA which carries a particular protein.
What do different genes control?
The development of different characteristics of an organism.
How many chromosomes are in the human body?
46
How many pairs of chromosomes are in the human body?
23
What is variation?
When individuals of a species look similar but are not identical.
What is inherited variation?
Variation due to genetic causes.
Give some examples of inherited variation.
Eye colour
Hair colour
Skin colour
Give two examples of variation.
Environmental and Inherited
How do characteristics of animal and plants vary in an environment?
Climate Diet Accidents Culture Lifestyle
What are different forms of a certain gene called?
Alleles.
How is a transgenic organism created?
Genetic modification or genetic engineering.
What is the sum total of our genes called?
Genotype
What are our characteristics in our appearance called?
Phenotype
What are the two different types of allele?
Recessive or Dominant
What is a recessive allele?
It only shows if the individual has two copies of the recessive allele. For example the allele for blue eyes is recessive.
What is a dominant allele?
It only shows if the individual has one copy of the dominant allele. For example, the allele for brown eyes is dominant.
What is genetic modification?
When a gene from one organism is put into the cells of another organism.
What is a transgenic organism?
An organism treated by genetic modification.
What is cloning?
The production of genetically identified copies.
What is the difference between genetic engineering and cloning?
Genetic engineering produces a set of unique genes and their genes can be swapped across species.
Cloning produces exact copies and the genes are copied within the same species.
What are the problems with genetic engineering?
Some people believe the process is unethical and should be banned.
What does IVF stand for?
In-Vitro Fertilisation
How does IVF work?
A woman’s egg is taken from her uterus, fertilised outside the body, and then implanted back into her uterus.
What are the ethical problems with IVF?
Couples may want ‘designer babies’ with ‘desirable’ qualities.
What does asexual reproduction produce?
Clones that are genetically identical to their parents.
Name two ways plants can be cloned.
Cuttings or Tissue Culture.
Name two ways animals can be cloned.
Embryo Transplants or Fusion Cell Cloning.
What are sex cells called?
Gametes.
What are the male and female sex cells?
Sperm and Eggs
What happens when gametes meet?
Fertilisation
What happens after fertilisation?
It produces a zygote that then develops into an embryo.
How many parents does asexual reproduction require?
One.
What are the advantages of cloning plants?
They can be produced cheaply and commercially, on a massive scale in a short period of time.
How do cuttings clone plants?
A cutting from the parent plant is taken and planted in damp compost. Plant hormones encourage new roots to develop. It is usually covered in a clear plastic bag to keep it moist and warm. After a few weeks roots develop and a new plant is produced.
How does tissue culture produce clones?
Small amounts of parent tissue or a number of cells are taken.
The plant material is transferred to plates containing sterile nutrient agar jelly.
Plant hormones are added to stimulate the cells to divide.
Cells grow rapidly into small masses of tissue.
More growth hormones are added to stimulate the growth of roots and stems.
The tiny plantlets are transferred into potting trays where they develop into plants.
How do embryo transplants produce clones?
A developing embryo is removed from a pregnant animal at an early stage, before the embryo’s cells have had time to become specialised. The cells are separated, grown for a while in a laboratory and then transplanted into host mothers.
When the offspring are born, they are identical to each other. They are not identical to their host mothers, because they contain different genetic information.
How does fusion cell cloning produce clones?
A egg cell was removed from the ovary of an adult female sheep, and it’s nucleus removed.
The nucleus from an udder cell of a donor sheep was inserted into the empty egg cell.
The fused cell then began to develop normally, using genetic information from the donated DNA.
Before the dividing cells become specialised, the embryo was implanted into the uterus of a foster mother sheep.
What is DNA?
The complex chemical that carries genetic information.
Where is DNA found?
Chromosomes.
What does a DNA molecule carry?
The different codes needed for different amino acids.