What are the medical applications of the Human Genome Project’s research? List at least three.
- Prediction and prevention of diseases
- Testing and treatment for inherited disorders
- Development of new and better medicines
These applications can lead to tailored medical advice and treatments.
What is one advantage of knowing which genes make people more likely to get diseases?
Individually tailored advice on diet and lifestyle
This could help avoid likely health problems.
How can genome research lead to the development of new drugs?
By highlighting genetic variations that affect treatment responses
This allows for drugs tailored to specific genetic profiles.
What causes genetic variation within a species?
- Different alleles (versions of genes)
- Mutations
- Sexual reproduction
Genetic variation leads to differences in phenotype, the characteristics displayed by an organism.
What are mutations?
- Changes to the base sequence of DNA
- Can result in new alleles
Mutations can be neutral, have slight effects, or rarely cause significant changes in phenotype.
What happens when a mutation occurs within a gene?
It results in an allele, or a different version of the gene
Most mutations do not affect the phenotype, but some can lead to slight or significant changes.
What is an example of a condition caused by a significant mutation?
Cystic fibrosis
A mutation affects a protein that controls salt and water movement in cells, leading to thick mucus production.
What is the role of environmental factors in variation?
- Influence phenotype
- Can lead to acquired characteristics
Environmental conditions, like sunlight or food availability, affect how traits are expressed.
How many matched pairs of chromosomes are in every human body cell?
23
The 23rd pair determines the sex of the individual.
What are alleles?
Different versions of the same gene
Alleles are represented by letters in genetic diagrams.
What does it mean if an organism is homozygous for a trait?
It has two identical alleles for that trait
Homozygous can be either dominant or recessive.
What does it mean if an organism is heterozygous for a trait?
It has two different alleles for that trait
Heterozygous organisms have one dominant and one recessive allele.
What is a genotype?
An individual’s specific genetic makeup
Genotype determines the phenotype.
What is a phenotype?
The observable characteristics of an organism
Phenotype is influenced by genotype.
What forms the backbone of DNA strands?
- Sugar molecules
- Phosphate molecules
The sugar and phosphate molecules alternate in the backbone.
Name the four different bases that join to each sugar in DNA.
- A (adenine)
- T (thymine)
- C (cytosine)
- G (guanine)
These bases pair up in specific ways to form the DNA structure.
Where are chromosomes found in eukaryotic cells?
In the nucleus
Chromosomes are long, coiled up molecules of DNA.
What is a gene?
A section of DNA on a chromosome that codes for a particular protein
The sequence of bases in the gene determines what protein is produced.
What is a genome
All of the DNA found in an organism’s cell
The genome encompasses all genetic information of an organism.
How to extract DNA from fruit
Mash fruit and mix with a solution (detergent, water and salt)
,add protease, heat and filter solution, pour ice cold ethanol into filtrate
The detergent breaks down cell membranes, while salt helps DNA stick together.
Why is ice cold ethanol added
To precipitate DNA
The DNA appears as a stringy white precipitate.
What are gametes in humans?
- Sperm cells
- Egg cells
Gametes contain half the number of chromosomes compared to normal cells.
What is the diploid number of chromosomes in humans?
46
The haploid number is 23.
What is a zygote?
A fertilized egg that has a full set of chromosomes (diploid)
Formed when a male gamete fuses with a female gamete.
