classic mendelian genetics Flashcards
what is interface
cell just sits there and performs normal functions
what is G1
prepares cell for replication by replicating organelles
why do some cells dont use all of the genes even if all cells contain the whole genome
some genes are turned off
what is meiosis 1
- chromosomes condense
- spindle forms
- homologous chromosomes
what is meiosis 1 and meiosis 2 seperated by?
interkinesis
what is genetic recombination
chromosomes pair up and parts of genetic material crosses over
what leads to trisomy 18
edward’s syndrome
what do females with 1 x chromosome suffer from?
turners syndrome
what does the posession of 3 x chromosomes lead to
metafemale syndrome
what is an allele?
different forms of a gene
what is a genotype?
person’s genetic makeup
what is the expression of a genotype?
phenotype.
what is mitosis?
cell divides and passes on all its DNA to the 2 daughter cells.
what is the S phase?
DNA replicates using DNA polymerase and adding complementary nucleotides.
what is G2?
enzymes needed for cell division are synthesised
What happens in early prophase?
centrioles start to migrate by pushing away from each other
chromosomes consist of sister chromatids
what happens in late Prophase?
- nuclear envelope fragments.
- spindles attach to chromosomes.
what is metaphase?
chromosomes along the equator
what is anaphase?
spindles contract and splits chromosomes and pulls each sister chromatid towards each pole.
what happens in telophase and cytokinesis?
nuclear envelope starts to reform
f actin contracts until cell is separate.
what is diploid number of chromosomes?
contains 2 copies of each chromosome.
what is Haploid number of chromosomes?
contains 1 copy of each chromosome.
what process are male gametes formed by?
spermatogenesis.
What process are eggs formed by?
oogenesis
what do 2 gametes produce?
diploid zygote
what is Meiosis 1?
homologous chromosomes seek each other out (synapsis) forming tetrads. 2 daughter cells
What is meiosis II ?
centromeres break and chromosomes move to opposite ends of cells
4 daughter cells.
what is independent assortment?
different combination of chromosomes
what is genetic recombination?
chromosomes pair up during synapses
parts of genetic material cross over.
what is random fertilisation?
different gametes pair up
what is non-disjunction?
chromosomes don’t completely separate.
what does Trisomy 21 cause?
Down’s syndrome
what does Trisomy 13 cause?
Patau’s syndrome
what do XXY males look like?
Kleinfelter’s syndrome
female traits.
how is the sickle cell anaemia gene beneficial?
protects against malaria.
what do heterozygous individuals with sickle cell anaemia produce?
produce both normal and sickled haemoglobin.
what is sex-linked inheritance?
involves sex chromosomes.
