Genetics Flashcards
(36 cards)
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
