1.3 - Inheritance Flashcards
How many chromosomes do somatic cells have?
46
What is mitosis?
The process by which somatic cells are formed
How many chromosomes do the sex cells have?
23
What is meiosis?
The process by which sex cells are formed
What is homozygous dominant?
Having two dominant alleles e.g BB GG
What is homozygous recessive?
Having 2 recessive alleles
What is heterozygous?
Having a dominant and recessive allele
What’s a phenotype?
The word description for a characteristc
What’s a genotype?
The genetic description for a characteristic e.g BB, ee, Ee
Why do men suffer from more sex related diseases than women?
Because the y chromosome is shorter so contains fewer genes
How can genetic profiling be used?
- fingerprinting can be used to place people at a crime scene
- evidence for a paternity case
How can DNA be used for closely related species?
- DNA Will be similar
- physical characteristics
What does genetic engineering mean?
It involved the transfer of genes from one organism to another using bacteria
What does transgenic mean?
Where an animal or plant contains foreign genes
What are bacteria?
-microscopic single celled organisms that do not have a proper nucleus
What do restriction enzymes do?
They cut DNA at specific points
What do plasmids do?
They carry genes that are resistant to antibiotics
3 examples of genetic engineering
- insulin production
- cystic fibrosis production
- haemophilia production
What are the advantages of genetic engineering?
- production of new organisms
- treats inherited diseases
- processes are cheaper and more efficient
What are the disadvantages of genetic engineering?
- inserted genes may be harmful as we have a lack of knowledge how they work
- new organisms could get out of control
- altered genes could be harmful to other organisms
How does genetic engineering happen?
- A plasmid is removed from a bacterium and a restriction enzyme cuts out a section
- The same enzyme cuts out a piece of human DNA which is then inserted into the plasmid
- The plasmid is inserted into the bacterium and it replicates by mitosis so each new cell has the new gene
E.g insulin gene
How does herbicide resistance in plants work?
- Selecting a gene for herbicide resistance and cutting into a plasmid
- Plasmid with a gene is inserted and so a plant becomes transgenic
- Growing seeds in a petri dish containing herbicide so only transgenic plants grow
- Transgenic plants grow in a field and farmer sprays throughout the year
Who discovered DNA?
Watson and Crick
