Biology - B1 Flashcards
What do all cells contain?
Nucleus
What do nucleus’s contain?
Genetic Material
What is a chromosome?
a long molecule of DNA that’s coiled up (inside a nucleus)
What is a Gene?
a short length of a chromosome
What do genes do?
they control the development of different characteristics and how an organism functions
What do genes code for?
making a certain protein
What controls characteristics like dimples?
only genes
What controls characteristics like eye colour?
several or one gene
What controls characteristics like scars?
environmental factors
what controls characteristics like weight?
environmental factors and genes
In body cells chromosomes come in …….?
pairs
what are different versions of the same gene called?
alleles
Alleles can be………..?
dominant or recessive
what do dominant alleles show?
dominant characteristics
what do recessive alleles show?
recessive characteristics
how many pairs of chromosomes are there in very human body cell?
23 pairs
what are the 23rd pair of chromosomes called?
XY
what do the XY chromosomes decide?
if your male or female
if genes are faulty what do they cause?
they can cause disorders
what are the symptoms of Cystic Fibrosis?
thick mucus - in the airways, gut and pancreas
breathing difficulty’s
chest infections
difficulty digesting food
Is Cystic Fibrosis recessive or dominant?
recessive
if a person has only one copy of a Cystic Fibrosis gene what are they known as?
carrier
how can a child get Cystic Fibrosis?
the parent must be a carrier or sufferer
What are the symptoms of Huntington’s Disease?
tremors (shaking) clumsiness memory loss mood changes poor concentration
When does Huntington’s Disease set in?
around the age of 40
what is Huntington’s Disease caused by?
faulty dominant allele of a single gene
Who can genetic testing be used on?
embryos
children
adults
what are the issues of genetic testing?
may not be accurate
people can be told they have a disorder when they don’t (false positive}
people don’t have a disorder when they do (false negative)
aren’t 100% safe
what type of sexual reproduction produces clones?
Asexual
what does Asexual reproduction mean?
reproducing without sexual reproduction
how do bacteria reproduce?
they divide in 2
what are stem cells?
unspecialised cells (cells without purpose that could turn into different types of cells)
what are embryonic stem cells?
unspecialised cells found in embryos and can turn into any kind of cell
what are adult stem cells?
unspecialised cells found in adults and can turn into many cell but not all of them
how can stem cells be used in medical procedures
to fix blood diseases bone marrow can be transplanted (bone marrow contains stem cells that can replace faulty ones)
