Intro To Genetics Flashcards
What is genetics?
The study of heredity and the transmission of genes and chromosomes from one generation to the next
It encompasses various subfields including transmission genetics, population genetics, and molecular genetics.
What are the main subfields of genetics?
- Transmission genetics
- Population, evolutionary genetics
- Quantitative genetics
- Molecular genetics
Define a gene.
A unit of inheritance, a specific location on a chromosome, a sequence of base pairs, transcribed into RNA, encodes a protein, and specifies a phenotype.
What are codons?
Three nucleotide sequences that specify a specific amino acid.
Can several genes encode one protein?
Yes, several genes may encode one protein.
Can one gene encode different proteins?
Yes, one gene may encode different proteins through mechanisms such as alternative splicing.
What percentage of the genome is protein-coding?
Less than 3% of the genome is protein-coding.
What is non-coding RNA?
RNA that does not encode proteins, which includes house-keeping ncRNAs and regulatory ncRNAs.
What is genetic variation?
Differences in DNA sequences among individuals, observed as SNPs (single nucleotide polymorphisms).
How do somatic mutations accumulate in individuals?
Somatic mutations slowly accumulate, with approximately 500 changes per cell.
What is the haploid genome?
A genome consisting of 23 chromosomes, approximately 3 billion base pairs of DNA, and about 25,000 genes.
How much do chimps and humans differ in DNA sequence?
Chimps and humans differ by about 1% of DNA sequence.
What is the difference between a chromosome and a chromatid?
A chromosome is a structure containing many genes, while a chromatid is one half of a duplicated chromosome.
What is the ploidy of gametes?
Haploid, meaning they contain one copy of each chromosome.
What is the difference between genes and alleles?
Genes are the basic units of heredity, while alleles are differing variants of a gene.
What is the definition of genotype?
A list of alleles carried by a specific individual.
What is the definition of phenotype?
The observable/measurable characteristics of an individual.
What is a dominant allele?
An allele that always produces a certain phenotype regardless of other alleles present.
What is a recessive allele?
An allele that does not produce a phenotype if a dominant allele is present.
How are dominant and recessive alleles represented?
Dominant alleles are represented with capital letters; recessive alleles are represented with small letters.
In genetic terms, what does the analogy of a song represent?
A song represents a gene, while the tape contains recorded information that represents DNA.
