evolution and genetics Flashcards
(28 cards)
What underlies biodiversity?
Genetic diversity
Genetic diversity is essential for the variety of life forms in an ecosystem.
What is the ultimate source of genetic variation?
Random mutations
Mutations occur randomly and contribute to the diversity of genetic traits.
What determines an organism’s phenotype?
Genotype and environment
The phenotype reflects the interaction of the organism’s genetic makeup with environmental factors.
What are the complementary base pairs in DNA?
A-T, C-G
These pairs form the rungs of the DNA double helix.
What type of molecule is RNA?
Polymer of ribonucleotides
RNA plays a crucial role in protein synthesis and gene expression.
What is the role of messenger RNA?
Intermediate between DNA and protein
mRNA carries genetic information from the DNA to the ribosome for protein synthesis.
What is the primary structure of proteins?
Sequence of amino acids
The primary structure determines the protein’s unique characteristics.
What are the two types of secondary structures in proteins?
Alpha helices, beta sheets
These structures contribute to the overall shape and function of proteins.
What did Beadle and Tatum propose in the 1940s?
One gene, one protein
This hypothesis suggests that each gene encodes a specific protein.
What did Hershey and Chase demonstrate in the 1950s?
Bacteriophage injects DNA, not protein
This experiment provided evidence that DNA is the genetic material.
What is genetic diversity?
Heritable variation within and between populations of organisms
It is essential for the adaptability and survival of species.
What is genetic variation?
Differences in the A, T, C, G sequence of DNA
This variation is crucial for evolution and natural selection.
What is epigenetic variation?
Differences in gene expression, not sequence
Epigenetic changes can affect phenotype without altering the DNA sequence.
What is a mutation?
A change in the sequence of bases in DNA
Mutations are the source of genetic variation and can lead to different traits.
What is a point mutation?
A small mutation
Point mutations involve a change in a single nucleotide.
What is a SNP?
Single nucleotide polymorphism
SNPs are variations at a single nucleotide position in the DNA sequence.
What is Haemophilia A caused by?
An inversion of a chromosomal region encoding the Factor VIII
This genetic disorder affects blood clotting.
What causes Smith-Magenis syndrome?
A deletion in the short arm of chromosome 17
This syndrome results in the loss of multiple genes.
What is XX male syndrome?
Translocation of a region of the Y chromosome to the X
This genetic condition can affect sexual development.
What characterizes Turner Syndrome?
Full or partial loss of X chromosome
This condition affects females and can lead to various developmental issues.
What types of mutations can exist with regard to their effects on phenotype?
Neutral, small, or large effects
Some mutations have no effect, while others can significantly change traits.
What happens during a population bottleneck?
Reduction in genetic diversity
This can occur when a population undergoes a dramatic reduction in size.
What is the impact of habitat fragmentation on genetic diversity?
Increased inbreeding
Fragmentation can isolate populations and reduce genetic variation.
