Mid Years Flashcards
What is a nucleus?
Location in a eukaryotic cell where the genetic material is stored.
What is a chromosome?
The coiled up form of a DNA molecule.
What is a gene?
A section of a chromosome which codes for a particular characteristic.
What is an allele?
Different versions of the same gene.
What is a dominant allele?
A characteristic which is expressed regardless of the paired allele.
What is a recessive allele?
A characteristic which is only expressed if paired with an identical allele.
What is a gamete?
A sex cell, in humans this is an egg or a sperm.
What is homozygous?
Both alleles for a particular characteristic are identical.
What is heterozygous?
The alleles for a particular characteristic are different.
What is genotype?
The genes and alleles which determine the characteristics of an organism.
What is phenotype?
The physical expression of the characteristics in an organism.
Define the 5 steps involved in selective breeding
1.The Characteristics that are desirable are chosen e.g. blue flowers.
2.Humans choose Two parents that express these characteristics.
3. Breed them together.
4. The Offspring that have the desired characteristics are selected and bred with an
organism that also expresses the Characteristics.
5. Repeat the process over many generations. (over a number of years).
What happens to a Human Cell in genetic engineering
- The DNA containing the desired gene is removed from the cell
- Enzymes then work to cut out the desired gene
- The Enzymes then insert the Human gene into the Bacterium DNA
- The Bacteria reproduce rapidly. This creates bacteria with the new Characteristic
What happens to a Bacteria Cell in generic engineering
- DNA is taken from the Bacterium
- Enzymes insert the Human gene into the Bacterium DNA
- The Bacteria reproduce rapidly. This creates bacteria with the new Characteristic
What are the stages of Nuclear Transfer Cloning. E.G. Sheep
Note: (One side explains the Selected Sheep and the Other is the Female Donor)
Selected Sheep 1. Body Cell removed from Sheep to be Cloned. Female Donor 1. Egg cell removed.
Selected Sheep 2. Nucleus is removed and kept. Female Donor 2. Nucleus is removed and discarded.
- Nucleus and Egg cell Fuse. VIA electric shock
- Cell division occurs (one cell becomes many)
- Implant the egg cell into a Surrogate mother (Female sheep that carries and gives birth to the lamb)
- The Cloned sheep is born.
How do you express a Dominant allele. e.g. Brown eyes
Using a CAPITAL letter. (B) for brown eyes
How do you express a Recesive allele. e.g. Blue eyes
lower case letter. (b) for blue eyes
What is the Meaning of DNA
Deoxyribonucleic acid
