Question 1
The biological insights of Mendel and Darwin in the 19th century remain important to this day.
Discuss the role of genes and chromosomes in determining individual and shared character features of the members of a species.
Genes
a. mutation changes genes/causes genetic differences
b. genes can have more than one allele/multiple alleles
OR
alleles are different forms/versions of a gene
c. different alleles «of a gene» give different characters
OR
variation in alleles between individuals
d. eye colour/other example of «alleles of» a gene affecting a character
e. alleles may be dominant or recessive
OR
dominant alleles determine trait even if recessive allele is present
f. both alleles influence the characteristic with codominance
OR
reference to polygenic inheritance
g. all members of a species are genetically similar/have shared genes OR certain genes expressed in all members of a species
h. reference to epigenetics/methylation/acetylation / not all genes are expressed «in an individual»
i. genes are inherited from parents/passed on to offspring/passed from generation to generation
Chromosomes
j. same locus/same position of genes
OR same sequence of genes/same genes on each chromosome «in a species»
k. same number of chromosomes «in a species»/all humans have 46 chromosomes/differences in chromosome number between species
I. some individuals have an extra chromosome/Down syndrome/other example of aneuploidy
OR
polyploidy divides a species/creates a new species
m. X and Y/sex chromosomes determine the sex/gender of an individual
n. meiosis/independent assortment/fertilization/sexual reproduction give new combinations «of chromosomes/genes»