Save
Upgrade to remove ads
Busy. Please wait.
Log in with Clever
or
show password
Forgot Password?
Don't have an account?  Sign up 
Sign up using Clever
or
Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account. Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't Know
Remaining cards (0)
Know
0:00
edit
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

BIO 1510 Chapter 11

terms

TermDefinition
sexual reproduction The process of producing offspring through an alternation of fertilization (producing diploid cells) and meiotic reduction in chromosome number (producing haploid cells).
gamete A haploid reproductive cell.
somatic cell Any of the cells of a multicellular organism except those that are destined to form gametes (germ-line cells).
zygote The diploid (2n) cell resulting from the fusion of male and female gametes (fertilization).
fertilization The fusion of two haploid gamete nuclei to form a diploid zygote nucleus.
syngamy The process by which two haploid cells (gametes) fuse to form a diploid zygote; fertilization.
meiosis occurs during gamete formation, producing cells with half the normal number of chromosomes. The subsequent fusion of two of these cells ensures a consistent chromosome number from one generation to the next.
sexual reproduction The process of producing offspring through an alternation of fertilization (producing diploid cells) and meiotic reduction in chromosome number (producing haploid cells).
germ-line cells During zygote development, cells that are set aside from the somatic cells and that will eventually undergo meiosis to produce gametes.
meiosis I homologous chromosomes separate, and the daughter cells have only the haploid number of chromosomes
meiosis II two haploid cells undergo a mitosis-like division without DNA replication to produce four haploid
synapsis The point-by-point alignment (pairing) of homologous chromosomes that occurs before the first meiotic division;
synaptonemal complex A protein lattice that forms between two homologous chromosomes, holding the replicated chromosomes with each other so that base-pairs can form between nonsister chromatids for crossing over that is usually exact within a gene sequence.
when does synaptonemal complex occur? in prophase I of meiosis
crossing over the exchange of corresponding chromatid segments between homologous chromosomes; responsible for genetic recombination between homologous chromosomes.
chiasma An X-shaped figure that can be seen in the light microscope during meiosis; evidence of crossing over, where two chromatids have exchanged parts;move to the ends of the chromosome arms as the homologues separate.
sister chromatid cohesion The process in which sister chromatids of each homologue are also joined by the cohesin complex
recombination nodules thought to contain the enzymatic machinery necessary to break and rejoin chromatids of homologous chromosomes.
Terminal chiasmata hold the homologous chromosomes together in metaphase I so that homologues can be aligned at the equator of the cell.
independent assortment the random assortment of alleles for each of the genes
anaphase I microtubules of the spindle fibers begin to shorten. As they shorten, they break the chiasmata and pull the centromeres toward the poles, dragging the chromosomes along with them.
telophase I chromosomes have segregated into two clusters, one at each pole of the cell. Now the nuclear membrane re-forms around each daughter nucleus
achiasmate segregation The lining up and subsequent separation of homologues during meiosis I without the formation of chiasmata between homologues
Prophase II at the two poles of the cell, each nuclear envelope breaking down as a new spindle forms.
Metaphase II spindle fibers from opposite poles bind to kinetochores of each sister chromatid, allowing each chromosome to migrate to the metaphase plate as a result of tension on the chromosomes from polar microtubules pulling on sister centromeres.
Anaphase II spindle fibers contract, and the cohesin complex joining the centromeres of sister chromatids is destroyed, splitting the centromeres and pulling the sister chromatids to opposite poles
Telophase II the nuclear envelope re-forms around the four sets of daughter chromosomes. Cytokinesis then follows.
nondisjunction Failure of chromosomes to move to opposite poles during either meiotic division. It produces one gamete that lacks a chromosome and one that has two copies.
aneuploid gametes Gametes with an improper number of chromosomes
1st distinct feature of meiosis Homologous pairing and crossing over joins maternal and paternal homologues during meiosis I.
2nd distinct feature of meiosis Sister chromatids remain connected at the centromere and segregate together during anaphase I.
3rd distinct feature of meiosis Kinetochores of sister chromatids are attached to the same pole in meiosis I and to opposite poles in mitosis.
4th distinct feature of meiosis DNA replication is suppressed between the two meiotic divisions.
Created by: 40011394
Popular Biology sets

 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
Retries:
restart all cards