Genetics and Inheritance Flashcards
what is DNA
the genetic material found in the chromosomes in the nuclei of cells
where is DNA found
nucleus
what is a chromosome
a string of genes/DNA
what is the shape of DNA
double helix
what are the 4 bases
Adenine
Cytosine
Guanine
Thymine
what are the complementary bases
AT
CG
what holds the DNA strands together
weak hydrogen bonds
DNA is a _________ made up of __________
polymers monomer
what is a DNA monomer called
a nucleotide
what is a nucleotide made up of
phosphate
sugar
base
what is the biggest molecule in nucleotide
sugar
what are the 3 steps to extracting DNA from fruit
- grind fruit to separate cells
- add detergent to break open the cell membranes
- add ice-code alcohol so that the DNA precipitates out
who discovered inheritance
Gregor Mendel
describe Mendels experiment
- Mendel created pure bread pees that would always produce the same offspring when bred
- he bred tall peas with dwarf spread and discovered that all the offspring were tall
- he discovered that the tall gene was dominant and the short gene was recessive
what is a game
a sex cell
what is made when 2 gametes fuse
a diploid zygote
what is a gene in terms of genetics
it codes for a particular characteristic
what is an allele
a different version of a gene
what does homozygous mean
when the person has the same allele for a particular characteristic on both chromosomes
what does heterozygous mean
when the person has different alleles for a particular characteristic on the chromosomes
what is the genotype
shows the alleles in the individual
what is the phenotype
means the characteristics that are produced
how many chromosomes do humans have
23 pairs or 46 chromosomes
what is the genotype of a male
XY
what is the genotype of a female
XX
what is the chance of your child being a male
50%
what 3 alleles are used to determine blood group and if they are recessive or dominant
A - dominant
B - dominant
O - recessive
what are the four blood groups
A
B
AB
O
how is the blood group AB possible
codominant, this occurs when the heterozygous individual shows the effects of both alleles that they carry for the gene
name 2 sex-linked disorders
colour blindness
haemophilia
what is meant by a sex-linked disorder
when a disease is more likely to affect males as they carry only one X chromosome a recessive allele on this chromosome will affect the phenotype as an allele on the Y chromosome will not match it
what 2 factors cause variation
genes and environment
what is a mutation
when the sequence of bases in a gene is changed
what was the human genome project
a collaboration between scientists to decode the human genome (the order of bases on all human chromosomes).
what are 3 advantages of the human genome project
- it can be used to alert people of any particular disease that they are at risk for so that they can change their lifestyle and prevent it
- can be used to distinguish between similar diseases
- allows doctors to tailor treatments, where specific alleles affect how a person will respond to a treatment
what are 2 disadvantages of the human genome project
people who are at risk of certain diseases may have to pay more for life insurance
it may not be helpful to tell someone they have an incurable disease
