Biology Unit 5 Test Flashcards
Define Somatic Cell
body cells, 2n, 2 copies of each chromosome
Define Gamete
reproductive cell, 1n, 1 copy of each chromosome
What is the main purpose of meiosis?
To create reproductive cells as 1n from the mother and father make 2n for the next generations’ body cells.
How is meiosis DIFFERENT from Mitosis?
2 rows of chromosomes lined up
Creates 4 haploid cells
Meiosis occurs twice
Additionally includes prometaphase
List the enzymes involved in DNA replication
Helicase - “unzips” the double helix in the parent DNA by breaking apart the Hydrogen Bonds holding the bases together
Primase - adds a primer of RNA to tell where to start the replication
DNA Polymerase - adds on complementary nucleotides to the 3’ end of the growing strand
Ligase - seals the nicks in the backbone of the lagging strand, between the Okazaki Fragments
What is the difference between dominant and recessive?
Dominant - an allele that always appears in the phenotype
Recessive - an allele only appears in the phenotype when there are 2 copies of it
What is the difference between an allele and a gene?
allele - a version of a gene
gene - most have 2 alleles which determine the trait that the gene will code
What is the difference between homozygous and heterozygous?
Homozygous - two copies of the same allele (AA, aa)
Heterozygous - one copy of each allele (Aa)
What is the difference between a phenotype and a genotype?
Phenotype - physical appearance of a trait due to a genotype
Genotype - the arrangement of alleles that results in a phenotype
What is the difference between monohybrid and dihybrid?
monohybrid - involves 1 pair of alleles with one trait
dihybrid - involves 2 pairs of alleles with 2 traits
Explain how a pedigree is autosomal dominant.
When at least one of the parents has it (dominant) and there are either the same number of males and females affected or when more males are affected than females (autosomal).
(dominant - most likely every generation has at least one person affected)
Explain how a pedigree is autosomal recessive.
When neither parents have it (recessive) and if more females are affected than males (autosomal).
(recessive - neither parents could have it or one parent could have it and the other is heterozygous)
Explain how a pedigree is x-linked recessive.
When neither parents have it (recessive) and if more males are affected than females (x-linked).
Explain how a pedigree is x-linked dominant.
When at least one parent is affected (dominant) and when more females are affected than males. (x-linked).
During what phase do homologous chromosomes swap genes in the process known as crossing over?
Prophase I
