E2 Module 7: Cell Division & Genetic Inheritance Flashcards
Exam 2
One parent cell divides into two identical daughter cells
Mitosis
How do prokaryotes do mitosis?
Reproduce asexually by copying themselves
How do Eukaryotes do mitosis?
Multiplies the somatic cells
All body cells aside from egg or sperm
Somatic cell
To prepare for mitosis, a cell replicates its entire genome, resulting
in ______________ __________ _____________
Two identical copies
Each replicated chromosome consists of two
identical
Sister chromatids
Sister chromatids are attached at the
Centromere
The step where cytoplasm gets divided as the cell pinches in two
Cytokinesis
One parent cell divides twice to produce four non-identical daughter cells
Meiosis
Eukaryotes use ________ to produce gametes (eggs & sperm) that contain only _____ of a parent’s genome.
Meiosis; half
These alternate copies of the same genes
are located on
Homologous chromosomes
_________ never stops, even when you have genes
Mitosis; helps form new skin cells
Homologous chromosomes = _____ genes, ______ alleles
Same; different
A cell with both sets of homologous chromosomes is ___________,
meaning it has two versions of each gene.
Diploid
the cell divides; homologous chromosomes
separate into different cells.
Meiosis I
paternal & maternal chromosomes are
_________ sorted into the two resulting cells, so that
each cell has a mix of maternal & paternal alleles for
each gene
Randomly
it has ONE
version of each gene; this happens when?
Haploid; end of meiosis I
both cells divide; sister chromatids separate
into different cells
Meiosis II
At the end of meiosis I, each cell is still _________: it has
one version of each gene.
Haploid
At the end of Meiosis II, there are ____________
4 gametes (reproductive cell)
When gametes are formed, the two alleles of a gene separate into
separate gametes, so that each gamete carries
just one allele of each gene
Law of Segregation
When gametes are formed, alleles of different genes get sorted into gametes independently of each other
Law of Individual Assortment
When the homologous chromosomes exchange a piece of themselves
Crossing over
Before crossing over: Two Homologous chromosomes are each made up of
two identical sister chromatids
Chromosomes with some paternal and some maternal
Recombinant chromosomes
Genes that are located close together on the same chromosomes are called
Linked genes
The farther apart two genes are, the (greater/less) the chance of a cross-over happening between them
Greater
The distantly spaces genes (follow/do not follow) the Law of Independent Assortment
Follow
A diagram that lets you chart all the possible allele combinations that could occur in an offspirng that results from a cross of two individuals with know genotypes
Punnett square
An organism’s combination of alleles for a particular gene
Genotype
individual has two of the SAME allele for a gene (ex: CB CB or CP CP)
Homozygous
individual has two DIFFERENT alleles for a gene (ex: CB CP)
Heterozygous
An organism’s combination of alleles for a particular gene
Genotype
An organism’s physical traits
phenotype (fein moshpits get physical)
Heterozygous individuals express the phenotype associated with this allele
Dominant trait
Heterozygous individuals DON’T express the phenotype associated with this allele
Recessive Trait
Most phenotypic traits ARE NOT… (3)
- Shaped exclusively by the genotype
- Shaped by only one gene
- Have on fully dominant and one fully recessive allele
Most traits are influenced by (one/multiple) genes
Multiple
When heterozygous individuals have a blended phenotype, instead of one or the other (Ex is CbCp instead of CpCp)
Incomplete dominance
When one gene has 3+ alleles, instead of just two (CxCx, CyCy, CzCz)
multiple alleles
When the “E”ffects of one gene override that of another gene
Epistasis
When a phenotypic trait is shaped by many different genes
Polygenic inheritance (poly=many)
this OR that
Addition or multiplication?
Addition
