His parents maybe a having the genotypes of GG and Gg. Galactosemia is a dominant allele so whoever gets the dominant allele, that person is positive to the disorder. Having a parent who is dominant homogeneous alleles crossed by a carrier could have a higher probability to have a child who will inherit this gene.
Answer:
There is less biodiversity in the ecosystem.
Explanation:
Since the barren ground doesn't provide suitable living conditions for most of the living organisms, the ones that need the lest resources to survive create the primary succession, usually the mosses and lichens. The organisms of the primary succession provide biomass, so the ground is mixing with it, thus new soil is forming.
Explanation:
I'm not sure but look online for the answers
Crossing over happens in Meiosis 1 only. In Prophase 1 a cells chromatin (chromatin = chromosomes that have not condensed yet) condense and pair up forming homologous chromosomes (paired = XX (2 chromosomes together)). When this happens segments/ alleles of the chromosomes pairing up swap over. This creates genetic diversity as each chromosome is different, it has parts from its pair. This leaves every chromosome unique and individual.
I hope this helps, sorry some of the vocab is rather technical. By the way I would suggest watching the
'Crash Course: Meiosis' on YouTube, this really helped me when I was learning this topic. :D