Topic 5

What are some reasons that cells typically divide? Growth Repair/replacement to reproduce

Circle one: The longest phase of the cell cycle is INTERPHASE / M phase

G1 is about cell __growth__.

How does a duplicated strand of DNA end up being identical to the original strand? In DNA replication one strand serves as a template for a new strand to be made, resulting in two DNA strands each with one old and one new strand.

The last stage of Interphase is G2.

In mitosis, the goal is to get cells that are genetically __identical __That is, we want to go 2N2N.

Match the following Mitosis stages to what happens C--Prophase a. Chromosomes move to opposite ends of cell D---Metaphase b. Nucleus reforms, DNA loosens, last stage A---Anaphase c. DNA condenses; nuclear breaks down B--Telophase d. Chromosomes line up in middle of cell

What is the difference between plant and animal cytokinesis? In cells without walls (animal cells ), it is accomplished by pinching of the cell. In plant cells, the wall prevents pinching; instead a new cell wall forms.

What does meiosis do to the number of chromosomes? Reduces the number of chromosomes by half, diploid cells become haploid

Meiosis goes from 2N N, or from diploid  haploid.

What is crossing over? process in which homologous chromosomes exchange pieces of their chromatids

When does crossing over happen? Prophase I

Topic 6

A Organism with two different alleles for the same trait __J___ Dominant allele __I___ F1 generation __K___ F2 generation __B___ Genotype __H___ Gregor Mendel __A___ Heterozygous __E___ Homozygous __C___ P generation __D___ Phenotype __F___ Punnett Square __G___ Recessive allele A Organism with two different alleles for the same trait Genetic makeup Parental generation Physical characteristics Organism that has two identical alleles for a trait Tool that can predict and compare genetic variation Allele that can be masked Priest who worked with garden peas First offspring generation Allele that can mask other alleles Second offspring generation

A monohybrid cross looks at ___1___ trait, while a dihybrid cross looks at __2__ traits at the same time.

What is Mendel’s idea of Dominance? the dominant trait is expressed if at least one dominant allele present Segregation? in meiosis, 2 alleles separate so that each gamete receives only one form of the gene Independent Assortment? each trait is inherited independently of other traits

When the dominant allele does not completely mask the recessive allele, it is called _Incomplete__ dominance. What are two examples? Pink flowers from red and white flowers crossing; purple feathers from red and blue crossing

When both alleles show up together (one is not really dominant over the other), it is called__codominance______. What are two examples? Speckled chickens and striped flowers

Sex-linked traits are those found on the _____X______ chromosome, and show up more in (circle one) males / females