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;
23 Cards in this Set
- Front
- Back
|
What is meiosis? |
A type of cell division that produces four daughter cells each with half the number of chromosomes of the parent cell. |
|
|
Where does meiosis occur? |
In sex organs of sexually reproducing organisms. |
|
|
How many chromosome does meiosis make? |
They have a haploid number of chromosomes. (23 chromosomes) |
|
|
Purpose of meiosis? |
To produce gametes (eggs & sperm) that have half the number of chromosomes of the parent cell. |
|
|
What happens when meiosis goes wrong? |
May result in a miscarriage or lead to genetic disorders. |
|
|
What are gametes? |
Are special cells used in sexual reproduction. (Have haploid chromosomes) |
|
|
Brief steps of meiosis |
•In meiosis cells divide twice. •One parent cell divides to produce two daughter cells. •These daughter cells then divide again to reproduce four daughter cells. •the final four daughter cells are haploid, that means they only have one copy of chromosomes, |
|
|
Prophase 1 |
•crossing over occurs •Nucleus disappears •Nuclear membrane breaks down •centrioles migrate to the poles |
|
|
Metaphase 1 |
Homologous pairs line up at the equator of the cell. |
|
|
Anaphase 1 |
Homologous chromosomes move to opposite poles of the cell. |
|
|
Telophase 1 |
Homologous chromosomes reach the cells opposite sides. |
|
|
Prophase 2 |
•new spindle appears •chromosomes become visible •nucleus disappears •nuclear membrane breaks down
|
|
|
Metaphase 2 |
•Chromosomes line up at the equator of the cell. •each chromosome has a spindle fibre attached to its centromere. |
|
|
Anaphase 2 |
•pairs of chromatids separate to now be referred to as chromosomes •chromosome are pulled apart at the centromere. •centromere separate |
|
|
Anaphase 2 |
•pairs of chromatids separate to now be referred to as chromosomes •chromosome are pulled apart at the centromere. •centromere separate |
|
|
Telophase 2 |
•spindle disappears •four daughter cells are produced, each with a set of haploid (23) set of chromosomes. |
|
|
What are alleles? |
Variations of genes |
|
|
What are homozygous? |
2 alleles that are the same |
|
|
What are heterozygous? |
Combination of alleles. |
|
|
What is genotype? |
The genetic info. |
|
|
What are phenotype? |
The observable characteristics. |
|
|
What are homologous pairs? |
Is when 2 chromosomes are similar in length, gene position and centromere location. (Pair up) |
|
|
Mother & father |
•Maternal chromosome come from the mother. •Paternal chromosome comes from the father. |
