Which of the following statements regarding the function of mitosis or meiosis is correct?
Mitosis allows somatic cells in an organism to reproduce asexually
Genes on the same chromosome are
Linked but may be separated by crossing over in prophase 1
Sexual reproduction could be compared to a card game where
Some combinations of cards are better than others but the same cards are always played. Alleles in a population are shuffled. Some combinations of alleles are better than others
Dominant alleles
Are always expressed as part of that organism’s phenotype
A trisomy results when
Homologous chromosomes fail to separate in anaphase I or sister chromatids fail to separate in anaphase II
Sex determination in certain bees and wasps is very different to humans. They exhibit
Haplodiploidy where males are haploid and females are diploid. The males don’t have fathers but grandfathers
Hypercholesterolemia
Individuals that are homozygous for the allele that doesn’t make LDL receptors have the full disease causing them to have very high cholesterol levels
Codominance
The expression of both alleles for a trait in a heterozygous individual
Mutations
Are the only source of new alleles in a population
Anaphase I
Homologous chromosomes separate
Random fertilization
Occurs when 2 haploid gametes fuse to form a diploid zygote
Meiosis 1
Sister chromatids combine to form tetrads and the tetrads are pulled apart forming 2 daughter cells with sister chromatids
Crossing over
Recombines linked genes into assortments of alleles not found in the parents. Happens in meiosis 1, prophase
Alleles
Are different versions of a gene. Humans can have 2 alleles at each locus because we are diploid
Locus
Location on a chromosome where genes are located
Thomas H Morgan
Discovered mutations and linked genes
Down’s syndrome
A trisomy on chromosome 21
Mendel’s law of independent assortment
Chromosomes sort independently of each other during gamete formation
Meiosis 2
Sister chromatids are separated
