sem 1 yr 10 sci exam

what does it mean when an atom is oxidised (3 points)

it has lost electrons, highly reactive and metals mostly oxidise

What does it mean when an atom is reduced (3 points)

it has gained electrons, are highly reactive and non-metals reduce

when does reducing strength decrease and oxidation increase on the periodic table (1 point)

left to right

ionisation (1 point) (happens in oxidisation)

energy used to move electrons from the valence shell

electronegativity (happens in ionisation) (1 point)

ability of an atom to gain electrons

what is dna made of (3 points)

phosphate group, deoxyribose sugar nitrogenous base

nitrogenous base pairs (4 points)

adenine, thymine, guanine, cystotine

what nitrogenous pairs go together (2 points)

a=t g=c

what do phosphates do in dna (1 point)

link neighbouring nucleotides

list what makes dna (different from rna) (3 point)

double stranded, deoxyribose sugar, basic bases

what is rna (difference from dna) (3 points)

single stranded, ribose sugar and uracil instead of thymine

what is co-dominance (1 point)

when both alleles in a heterozygote are equally expressed

incomplete dominance (1 point)

neither phenotypes show up so a 3rd phenotype is the intermediate of both

true or false: is the y chromosome shorter than the x chromosome (1 point)

true

genetic mutation (1 point)

permanent change in DNA sequence