TOPIC 10 & 11 Genetics Flashcards
What is a Genotype
The genetic makeup of an individual.
Eg. Eyes
What is a Phenotype:
The observable traits or characteristics of an organism.
E.g Blue coloured eyes
What is a Genome:
The complete set of an organism’s genes.
What is an Allele:
Different versions of a gene.
What is Recombination:
The reshuffling of genetic material during meiosis.
What is an Autosome:
Non-sex chromosomes.
What are Sex-linked genes:
Genes located on the sex chromosomes (X and Y).
What is a Dominant allele:
An allele that masks the effect of the recessive allele.
What is a Recessive allele:
An allele whose effect is masked by the dominant allele.
What is a Heterozygous gene:
Having two different alleles for a particular gene.
Eg. Aa
What is a Homozygous gene:
Having two identical alleles for a particular gene.
Eg. aa
What are Homologous chromosomes:
Chromosomes that carry the same genes but may have different alleles.
Eg. a human arms and the wings of a bat
Explain the significance of alleles in terms of heredity patterns
Alleles determine the specific traits an individual will inherit from their parents
How does genetic recombination affect genetic diversity
It produces unique combinations of alleles and therefore diverse phenotypes
What do dominant alles a required for a disease to manifest?
Dominant disorders require only one copy of the disease-causing allele to manifest
E.g Aa
What do recessive alles are required for a disease to manifest?
recessive disorders require two copies (homozygous)
Eg. AA
What happens in co-dominance
Co-dominance leads to both alleles expressing their traits in a heterozygote
eg red and blue fish = reds and blue on the fish
What happens in incomplete dominance
Incomplete dominance results in a heterozygote with an intermediate phenotype.
Eg. red fish and blue fish = purple fish
What is Sex-linked inheritance?
Sex-linked inheritance involves genes located on the X or Y chromosomes, leading to gender-specific inheritance patterns.
What is a genetic mutation?
A mutation is a change in the DNA sequence
How do mutations occur?
Errors in DNA replication, exposure to mutagens (e.g., radiation, chemicals), or spontaneous changes.
What is a point mutation (substitutions):
Point mutations (substitutions): Single base changes that may or may not alter protein production
What are insertion and deletion (indels) mutations:
Insertions and deletions (indels): Additions or removals of DNA bases, which can lead to frameshift mutations.
What are Silent mutations:
Silent mutations: Point mutations that do not affect the resulting protein.
What are Nonsense mutations:
Nonsense mutations: Create a premature stop codon, leading to a truncated, non-functional protein.
What are Deleterious mutations :
Deleterious mutations are harmful and can reduce an organism’s fitness.
What are Advantageous mutations :
Advantageous mutations provide an advantage, enhancing the organism’s chances of survival and reproduction, contributing to evolution.
What is an A single nucleotide polymorphism (SNP) mutation?
A single nucleotide polymorphism (SNP) is a variation at a single DNA base, often with multiple alleles.
What is a point mutation :
A point mutation refers to a single base change in the DNA sequence and can include both SNPs and other base changes.
What are the Chromosomal rearrangements:
TID
Chromosomal rearrangements include translocations, inversions, and duplications.
What is Karyotype analysis:
Karyotype analysis is a technique to examine an individual’s chromosomes.
Aneuploidy is a condition where an individual has an abnormal number of chromosomes, which can result in genetic disorders.
Down syndrome, XXX syndrome, Edwards syndrome, Turner syndrome
What is Nucleic acid analysis:
Nucleic acid analysis, such as sequencing, is used to identify specific genetic mutations.
What are the advantages of genetic testing?
Advantages include early disease detection and informed decision-making.
What are the disadvantages of genetic testing?
Disadvantages may involve ethical, psychological, and privacy issues.
Why is mutation important in maintaining genetic diversity
Mutation introduces new genetic variation, which is essential for adaptation to changing environments and the evolution of species.
What do genetic counsellors do?
Genetic counselors provide information and support to individuals and families facing genetic conditions.
They help people make informed decisions about genetic testing and its implications.
What are the the ethical, legal and social issues involved with genetic testing:
These issues involve concerns about privacy, discrimination, consent, and the potential misuse of genetic information.
Describe the principle of pre-implantation genetic diagnosis (PGD)
PGD is a genetic testing method used in assisted reproduction to screen embryos for specific genetic conditions before implantation.
Describe the key concepts involved in the genetic engineering and the advantages/disadvantages to the methods described
Genetic engineering involves modifying an organism’s DNA. Advantages include creating disease-resistant crops, but ethical and ecological concerns exist.
