inherited characteristics Flashcards
alleles are different versions of…
the same gene
name characteristics that can be inherited
eyes, ears nose, colour of hair, facial features
what do dominant and recessive characteristics depend on?
dominant and recessive alleles
when are dominant alleles shown?
when present but recessive alleles are only shown in the absence of the dominant allele
what does a gene determine?
the characteristics of an off spring
what does dominant mean?
a dominant trait or gene
what does recessive mean?
the gene will only be effective if another gene (dominant gene) is present
each inherited characteristic is controlled by its genes
memorise
give examples of characteristics that are not inherited, but are caused by their environment
accent, scar
give examples of characteristics that are both effected by inheritance and by their environment
height, intelligence, body mass
name 3 disorders that are inherited
red-green colour blindness(colour blindness where red and green look the same), sickle cell anaemia( a mutated form of haemoglobin distorts the red blood cells into a crescent shape at low oxygen levels), cystic fibrosis (difficulty in breathing because his body produces too much mucus, which collects in the lungs
complete this sentence…most body cells have the same number of…
chromosomes
complete this sentence…the number of chromosomes depend on the…
species
how many pairs of chromosomes do humans have?
23 pairs 46 individual
where are chromosomes found?
in the nucleus of cells
what do chromosomes have in them?
genes
what sex chromosomes do women have?
YY
what sex chromosomes do men have?
XY
complete this sentence…a sperm will either carry an…
X or Y chromosome
complete this sentence…all eggs will carry an…
X chromosome
what pair of chromosomes determines a boy and a girl?
XX for females and XY or YX for males
why is their an equal chance of off spring being male or female?
because their is a random chance of which sperm fertilises the egg
what is genetic variation caused by (3 points)?
genes being mixed up when gametes are formed, genes coming from two parents (fertilisation) and changes in genes or chromosomes called mutations
what does homozygous mean?
having identical alleles
what does heterozygous mean?
having different alleles
what is a persons genotype?
is their genetic make-up
what is a persons phenotype?
there alleles which are expressed
what are inherited disorders caused by?
faulty genes
name a personal issue when knowing if your baby has a disorder before birth?
in deciding to have a genetic test a positive result could alter lifestyle, career and insurance.
name another personal issue when knowing if your baby has a disorder before birth?
by knowing the risks of passing on an inherited disorder could effect whether to have a baby or not
it is impossible to predict the probability of inheriting such disorders by interpreting genetic diagrams
memorise
which one of these is mostly a faulty gene? the dominant or recessive
recessive
how many chromosomes do gametes (germ cells; sperm and egg) have?
23
why are the number of chromosomes in a cell usually an even number?
so chromosomes separate when egg and sperm are formed
how many chromosomes does a fertilised egg have?
46
complete this sentence…genes are in chromosomes in the nucleus of every cell apart from?
red blood cells
dominant is more dominant than a recessive
memorise
a recessive allele is a denatured allele e.g. Aa not AA
memorise
