Inheritance, Variation and Evolution Flashcards
What does DNA stand for?
DNA stands for deoxyribonucleic acid
What is DNA?
The chemical a cell’s genetic material is made from
What is the structure of DNA called?
The structure of DNA is a double helix
What is a chromosome?
A chromosome is a long molecule of DNA that normally come in pairs
How many pairs of chromosomes do humans have?
Humans have 23 pairs of chromosomes
What is the male chromosome?
The male chromosome is XY
What is the female chromosome?
The female chromosome is XX
What is a gene?
A gene is a small section of DNA found in a chromsome
What does a gene code for?
A gene codes for a specific sequence of amino acids
What is a genome?
A genome is an entire set of genetic information
What do genomes help us better understand?
Genomes help us better understand inherited disorders and the migration patterns of past populations
What are the things that make up a nucleotide?
The phosphate, sugar-phosphate backbone, sugar and base up a nucleotide
What are the base pairs?
A + T / C + G
What is the first stage of protein synthesis?
The first stage of protein synthesis is transcription, which is where the bases of genes are copied into an mRNA strand. The mRNA strand then passes out of the nucleus into the cytoplasm
What is the second stage of protein synthesis?
The second stage of protein synthesis is translation. The mRNA attaches to the ribosome. Amino acids are brought to the ribosome on carrier molecules (RNA). The ribosomes read the bases on the mRNA to join the correct amino acids in the correct order.
What are four characteristics which could be selected for the breeding of animals and plants?
- Disease resistance in crop plants
- Animals that produce more meat or milk
- Domestic dogs with a gentle nature
- Large or unusual flowers
What is a major disadvantage caused by selective breeding?
A large disadvantage caused by selective breeding is that it can lead to interbreeding where some breeds are particularly prone to disease or inherited defects
How often do mutations occur?
Mutations occur continuously
How likely is it that a mutation will lead to a new phenotype?
It is very rare that a mutation will lead to a new phenotype
What is a phenotype?
A phenotype is an individual’s observable traits, such as height, eye colour, and blood type
What is a genotype?
The genotype is the collection of alleles that determine an organism’s characteristics
What are examples of GM organisms?
Examples of GM organisms include;
- Insulin-producing bacteria (human insulin gene injected from bacterial cells to produce insulin for diabetes)
- Crops that can kill pests, resist herbicides and have increased shelf life
- Sheep that can produce drugs in their milk
What is the process of insulin being made from bacteria?
The process of insulin being made from bacteria include;
1) . remove the desired gene with a restriction enzyme
2) . cut plasmid open with restriction enzyme
3) . ligase enzyme inserts a gene into the plasmid
4) . plasmid put back in bacteria
5) . bacteria cultured in the fermentor
6) . lots of insulin is produced
What are the pros of genetic engineering?
The pros of genetic engineering are that it produces lots of cheap food, less waste due to pests, more money for farmers and extra nutrients in food
