B16.1 Chromosomes and genes (2025+)

Define inheritance

the transmission of genetic information from generation to generation

Define chromosome

thread-like structure of DNA, carrying genetic information in the form of genes

Define gene

length of DNA that codes for a protein

Define allele

a version of a gene

What sex chromosomes does a male have?

XY

What sex chromosomes does a female have?

XX

Draw a punnett square to predict the inheriance of having a baby boy

Two squares are XX & 2 squares are XY - the chance of being is boy is 2:2 or 50%

Define halpoid nucleus

a nucleus containing a single set of unpaired chromosomes e.g. in gametes

Define diploid

a nucleus containing two sets of chromosomes (one inherited from the mother and one inherited from the father), e.g. in body cells

Are gametes haploid or diploid?

haploid

Are body cells haploid or diploid?

diploid - there is a pair of each type of chromosome

How many pairs of chromosomes are there in a human diploid cell?

23 pairs (46 chromosomes in total)

What are proteins made of?

amino acids

What determines the order of amino acids in a protein?

the sequence of bases in a gene is the genetic code for putting together amino acids in the correct order to make a specific protein

Where in a plant/animal cell is DNA found?

In chromosomes in the nucleus