variation and classification Flashcards
what are the 2 types of keys
numbered keys and branching keys
define genes
a set of instructions located in the nucleus of every cell.
what do genes do
control growth and development
describe how an egg becomes an embryo
the nucleus of the sperm joins with the nucleus of the egg and fertilises an egg. the fertilised egg divides making many cells and forms an embryo. the new cells are contained in the embryo.
what do characteristics rely on
genes and environment
how does the environment affect one’s characteristics
environment affects one’s upbringing, culture, lifestyle and so on
give an example on how environment could affect one’s characteristics
for example if you’re parents speak mandarin but you grew up speaking english that means the environment you grew up in changed that
name a characteristic controlled by genes only
blood group
name a characteristic controlled by genes and environment
height
name a characteristic controlled by environment only
language spoken
define chromosomes
long thin threads found in a cell nuclei containing genetic material
what are chromosomes made out of
DNA
how many chromosomes in one cell
2
how many pairs of chromosomes does a human usually have
23
how many chromosomes does a human usually have
46
