2.2 Producing Gametes Flashcards
What is a Gamete?
A reproductive cell
What is a Zygote?
A cell formed by the fusion of 2 Gametes (reproductive cells: 1 maternal, 1 paternal)
What is a Gene?
This is a specific sequence section of DNA
☄️What is an Allele?
Example?
This is the different versions of a specific gene. For example we all have a gene for eye colour, however the allele will determine whether it’ll be brown, blue, etc.
(This is what the gene codes for.
Ex. Eye colour Allele.)
What is a homologous pair?
An identical set of chromosomes. (Maternal and paternal can be an ‘identical’ pair, if for ex. both are chromosome 2. It’s NOT homologous if one is chromosome 3 and the other is 10)
What is Meiosis?
The process of producing gametes that have a haploid number of chromosomes, from a diploid ‘germ’ cell.
What are the outcomes of Meiosis? (2)
- Genetic Reduction: Reduces amount of chromosomes
- Genetic Recombination: Increases diversity as DNA exchanges pieces
What is a ‘germ’ cell?
It is a diploid cell that produces gametes through meiosis. (The precursor of gametes; sperm, egg cell
What occurs in Prophase 1?
Maternal and paternal chromosome pairs find each other and cross over each other to exchange pieces.
What happens in Metaphase 1?
Homologous chromosomes(1 maternal, 1 paternal) line up along the equator. The side (left or right) that the chromosomes line in is random and by chance.
What happens in Anaphase 1?
Chromosomes separate and get pulled to opposite poles
What happens in telophase 1?
Two haploid cells result from cytokenisis
How is meiosis 2 different from meiosis 1?
Meiosis 1: Chromosomes separate in anaphase
Meiosis 2: Chromatids separate in anaphase
What’s the difference between Mitosis and Meiosis 2?
Mitosis starts as a diploid due to DNA replication in Interphase.
Meiosis 2 starts as haploid because no DNA duplication.
What occurs in Prophase 2?
Spindle fibers start to form
What happens in Metaphase 2?
Chromosomes line up in the equator
What happens in Anaphase 2?
Chromatid separate and are pulled to opposite poles
What happens in Telophase 2?
The cell goes through cytokinesis and splits
What is the product of Meiosis?
Haploid Gamete (reproductive cell)
What process produces gametes?
Meiosis
How many sperm cells does meiosis make?
4 sperm cells
How many egg cells does meiosis make?
1 egg cell and 3 polar bodies (small and arent used for reproduction)
What is process of meiosis that result in sperm cells?
Spermatogenisis
What is the process of meiosis that results in egg cells?
Oogenisis
What is the male germ cell (that make sperm)
Spermatogonia
What is the female germ cell called (make egg cells)
Oogonia
What’s the difference of Meiosis vs Mitosis? (What are they, literally)
Mitosis is for all cells except reproductive. Meiosis is for reproductive cells.
⭐️What are diploid vs haploid cells?
