Inheritance, Variation and Evolution Flashcards
what are chromosomes?
long molecules of DNA
What does DNA stand for?
DeoxyriboNucleic Acid
what is DNA?
the chemical that all genetic material in a cell is made up from
what does DNA do?
contains coded information - instructions to put an organism together and make it work
what does you DNA determine?
what inherited characteristics you have
where is DNA held in a plant and animal cell
In the Nucleus
DNA is a polymer. What’s a polymer?
large molecules made up of repeating units called monomers
What shape is DNA in?
two stands of DNA coiled up in the shape of a Double Helix
What’s a gene?
a small section of DNA found on a chromosome
What’s a genome?
the entire set of genetic material in an organsim
Each gamete contains how many chromosomes?
23 chromosomes
how many chromosomes does a normal cell contain?
23 pairs
46 in total
the chromosomes in egg cells and sperm cells fuse together so that the offspring has…
46 chromosomes
what creates variation in offspring?
a mixture of genetic information
How are gametes produced?
Meiosis
what type of cell division happens in asexual reproduction?
Mitosis
What does Meiosis produce?
cells with half the normal number of chromosomes
In Meiosis wat does the cell do before it starts to divide?
duplicates its genetic information and forms two armed chromosomes
In the first division on Meiosis what happens?
the chromosome pairs line up in the centre of the cell
and are now pulled apart
In the second division on Meiosis what happens?
The chromosomes line up again in the centre of the cell. The arms of the chromosomes are now pulled part
What controls weather your male or female?
chromosomes
out of 23 pairs the 23rd pair does what?
decides your gender and is labelled either xx or xy
what combination of chromosomes does a male have?
XY
what combination of chromosomes does a female have?
XX
