Genetics Flashcards
What is asexual reproduction
Reproduction involving one parent, producing genetically identical offspring through mitosis
What is sexual reproduction
The joining of male and female gametes producing genetically varied offspring
Advantages of sexual reproduction
- Produces variation
- Aids survival in changing environments
- Decreases extinction risk
- Allows for selective breeding
Advantages of asexual reproduction
- Requires only one parent
- Faster
- Uses less energy
- Produces many identical offspring in favorable conditions
What is meiosis
A process producing four genetically different haploid gametes from one cell
What is the structure of DNA
DNA is a polymer of nucleotides with a double-helix structure containing sugar, phosphate, and bases which are held together by complementary base pairing
What is a genome
All the genetic information in an organism.
What is protein synthesis
The process of making proteins from DNA
Types of genetic mutations
- Insertion: Adds a base, altering the reading frame
- Deletion: Removes a base, altering the reading frame
- Substitution: Changes one base; may or may not affect the amino acid
What is codominance
When two dominant alleles are expressed together
What are Mendel’s key findings
Traits are inherited through ‘hereditary units’ (genes), one from each parent, can be dominant or recessive
What is sex-linked inheritance
Traits linked to genes on sex chromosomes, often X-linked
Difference between genotype and phenotype
- Genotype = The genetic makeup of an individual
- Phenotype = The physical expression of traits
What is a punnett square
A diagram used to predict the probability of offspring inheriting particular genotypes and phenotypes
What are gametes
Reproductive cells with half the number of chromosomes (23) compared to body cells
What are alleles
Different forms of the same gene, inherited from each parent
What is a dominant allele
An allele that expresses its trait with just one copy present
What is a recessive allele
An allele that requires two copies to express its trait
What happens during fertilisation
Gametes fuse - combining genetic material to form a zygote with the full number of chromosomes (46 in humans)
What is complementary base pairing
In DNA, Adenine (A) pairs with Thymine (T), and cytosine (C) pairs with guanine (G)
What are nucleotides made of
A sugar molecule, a phosphate group, and one of four organic bases (A, T, G, C)
What is the role of RNA polymerase in protein synthesis
RNA polymerase binds to non-coding DNA before a gene, separates DNA strands, and assembles mRNA by matching complementary bases
What are tRNAs and their role
Transfer RNAs (tRNAs) carry specific amino acids to ribosomes during protein synthesis, matching their anticodons to mRNA codons
What is a mutation
A change in the DNA sequence that can affect protein structure and function, depending on whether it occurs in coding or non-coding reginos
Examples of sex-linked conditions
Hemophilia and red-green colour blindness
What is the Human Genome Project
A research project that mapped the entire human genome, aiding in understanding disease, genetic disorders, and human migration
What is Mendelian inheritance
The inheritance of traits based on dominant and recessive alleles, as demonstrated by Gregor Mendel’s pea plant experiments
What is multiple-gene inheritance
Traits influenced by many genes, such as eye colour, which involves up to 16 genes
What is pedigree analysis
A tool to track inheritance patterns of traits or conditions through generations using family trees
Why is meiosis important for genetic variation
It shuffles chromosomes and produces gametes with different genetic combinations
What are the uses of Punnett squares in genetics
To calculate probabilities of offspring inheriting specific genotypes and phenotypes
What causes variation in phenotypes
- Genetic variation: From mutations or sexual reproduction
- Environmental variation: Changes due to external factors, not inherited
What is the role in bromelain in extracting DNA
Bromelain, an enzyme in pineapple juice, breaks down proteins bound to DNA, helping to isolate it
Why is ethanol used in DNA extraction
Ethanol precipitates DNA, making it visible as a white mass in the solution
What is the difference between coding and non-coding DNA
- Coding DNA = Directly codes for proteins
- Non-coding DNA = Regulates gene expression or has other functions
What is a zygote
A diploid cell formed after the fusion of two haploid gametes during fertilisation
