3.1 + 3.2 genes and chromosomes Flashcards
what is a gene?
a heritable factor that consists of a length of DNA and influences a specific characteristic
what are alleles?
the various specific forms of genes
how are new alleles formed?
by mutation
new alleles form as a result of mutations, contributing to increased…
genetic variation
sickle cell anaemia is caused by ___________ mutation
base substituition
why is haemoglobin different in an individual with sickle cell anaemia?
- due to base substitution mutation in gene coding for haemoglobin protein
- which leads to a change in the base sequence of mRNA transcribed
- this leads to a change in the sequence of polypeptide in haemoglobin
sickle cell anaemia is an [autosomal/sex-linked] disorder
autosomal
what is the difference in RBC in a healthy individual and an individual w sickle cell anaemia?
healthy: biconcave shape
sickle cell anaemia: sickle shaped
what are the implications of individuals w sickle cell anaemia?
sickle cells may clump together and clog blood vessels, interfering w blood circulation
sickle cell anaemia is [recessive/dominant]
recessive
what are 2 symptoms of sickle cell anaemia?
chronic anaemia and jaundice
what is a genome?
it refers to all the DNA present in an individual
what is the human genome project for?
- to work out the base sequences of the human genome
- and identify the location of these genes
what are some outcomes of the human genome project?
- mutations can be located and genes associated with diseases can be identified
- tests for genetic diseases can be developed → earlier detection
- evolutionary history can be studied
prokaryotes have circular DNA while eukaryotes have _______ DNA
linear
what is the opposite of naked DNA?
DNA associated w histones
___karyotes have homologous chromosomes
eukaryotes
eukaryotes have… but prokaryotes don’t have these
centromeres, telomeres, homologous chromosomes