Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
50 Cards in this Set
- Front
- Back
|
What are the four phases of mitosis?
|
prophase, metaphase, anaphase, and telophase
|
|
|
What is the following phase of mitosis: spiondle fibers disappear, nuclear envelope disappears, chromatin cendense to chromosomes?
|
prophase
|
|
|
What occurs during metaphase in mitosis?
|
chromosomes line up along metaphase plate
|
|
|
What occurs during anaphase in mitosis?
|
the sister chromatids begin to pull away from each other toward opposite poles
|
|
|
What occurs during telophase of mitosis?
|
the cell splits to two cells and the nuclear envelope begins to appear and the spindle fibers disappear
|
|
|
When does crossing over occur?
|
prophase in mitosis, prophase I in meiosis
|
|
|
What is crossing over?
|
when two chromosomes get close together and part of them splits and the two chromosomes switch DNA
|
|
|
What is the chiasma?
|
the area during crossing over where the chromosomes attatch
|
|
|
What is synapsis?
|
the action of the arms coming together in crossing over and forming the chiasma
|
|
|
What is the main advantage of crossing over?
|
It increases gwnwitc diversity
|
|
|
In meiosis, what happens during metaphase I?
|
the homolgous chromosomes meet at the metaphase plate
|
|
|
When does crossing over occur?
|
prophase I
|
|
|
In meiosis, what occurs during prophase I?
|
the spindle fibers appear, the nuclear envelope disappears, chromatids form chromosomes, and homologous chromosomes pair up
|
|
|
What happens during anaphase I?
|
the homologous pairs split and go to opposite poles
|
|
|
What occurs during telophase I?
|
the cell splits into two and forms nuclear envelope and the spindle fibers dissappear
|
|
|
Meiosis II is basically _____, but instead of forming two diploid cells, four ____ cells are formed
|
mitosis, haploid
|
|
|
What is interphase?
|
the stage of the cell in which DNA replication and cell growth occurs
|
|
|
What are the stages of interphase and what occurs during these phases?
|
G1,growth, S,growth and DNA replication, G2, growth and prep for division
|
|
|
How many chromosomes are in human somatic cells?
|
46
|
|
|
How many chromosomes are in human haploid cells?
|
23
|
|
|
What are gametes?
|
cells produced in meiosis-eggs and sperm
|
|
|
What is a zygote?
|
the result of fertilization
|
|
|
What are pyrimidines?
|
cytosine and thyamine
|
|
|
What are purines?
|
adenine and guanine
|
|
|
What are the enzymes involved in DNA replication?
|
helicase, DNA polymerase, ligase, primase
|
|
|
What does helicase do?
|
"unzips" DNA
|
|
|
What does primase do?
|
initiates DNA replication at certain nucleotides
|
|
|
What does DNA polymerase do?
|
attatches new nitrogenous bases to unzipped DNA
|
|
|
What does ligase do?
|
joins two okazagi fragments together on lagging strand
|
|
|
What are Okazagi Fragments?
|
the fragments on the lagging strand of DNA in which DNA is replicated
|
|
|
Whay is DNA said to be anti parallel?
|
on side goes from 5' to 3' and the other goes from 3' to 5'
|
|
|
What is the only way that DNA can be replicated?
|
from 5' to 3'
|
|
|
What are linked genes?
|
two seperate genes that are close on the chromosome and therefore tend to show up together
|
|
|
When most of the young of the parents look like the parents we attribute _____
|
linked genes
|
|
|
What is dosage compensation?
|
a mechanism that makes it so males and females have the same amount of genetic information when related to the X chromosome
|
|
|
What is a barr body?
|
a condensed X chromosome in women to make it so women and men have the same amount of genetic material
|
|
|
What does Mendels principle of independant assortment?
|
allels of different loci are disributed randomly into the gametes
|
|
|
What does it mean to be recombinant?
|
you don;t look like your parents
|
|
|
What is mendel's principle of segregation?
|
during meiosis, the alleles for each locus seperate and when haploid gametes are formed, each contains only one allele for each locus
|
|
|
What is incomplete dominance? Give an example
|
When both traits are displayed together-red flower + white flower = pink flower
|
|
|
What is codominance? Give an example
|
When both traits show up-blood type AB
|
|
|
What is Pleiotropy? Give an example
|
When one gene has multiple affects-cystic fibrosis
|
|
|
What is epistasis?
|
when one allele affects how another one shows up
|
|
|
What is polygenic inheritance?
|
when many genes affect one trait-skin color
|
|
|
What is alteration of generation?
|
when part of life is haploid and the other part is diploid
|
|
|
What is the main function of DNA?
|
code for proteins
|
|
|
Give two examples of X-linked traits
|
color blindness and hemophelia
|
|
|
Why would a test cross be done?
|
You have something that shows a dominant trait, but you don't know if its homozygous or heterozygous, you mate it with a heterozygous recessive to determine the genotype
|
|
|
What do histones do?
|
provide structure for DNA to organize
|
|
|
Extra
|
Extra
|
