Chapter 2.6 Flashcards
(16 cards)
What is the difference between sexual and asexual reproduction?
Sexual reproduction involves the joining together if make and female reproductive cells (gametes). Meiosis is then used to produce an offspring.
Asexual reproduction doesn’t involve fusion of sex cells instead some eukaryotic organisms use mitosis for To asexually reproduce.
What is the difference between a haploid and diploid?
A haploid only has the possession of one coup of each chromosome in a cell - ‘n’ is the symbol to represent haploid cells
A diploid describes the paired set of chromosomes within a Somatic cell - ‘2n’ is used to represent diploid cells.
What is the difference between mitosis and meiosis?
Mitosis occurs in somatic cells where they genetically replicate themselves and become clones to the original for replacement, repair and growth in the body.
Meiosis is when gametes are produced for sexual reproduction. This process makes haploid cells.
Explain What Interphase is?
The Cell rests, and chromosomes are being duplicated
Explain what is prophase?
- Chromatin (uncoiled chromosomes) condense to become chromosomes
- Cell membrane begins to break down
- Centrioles near the nucleus splits in 2 and each half travels to an opposite pole of the cell
- a spindle made of microtubules form between then in cytoplasm.
What happens during metaphase?
- pro-metaphase ; nuclear membrane breaking apart and the spindle starts to interact with chromosomes.
- Spindle fibre attaches to the centromere of each pair of sister chromatids.
- chromatids line up at the centre of the equator and spindle fibres ensure that the chromatids are being pulled to opposite sides.
Explain what is Anaphase?
Sister chromatids seperate by their centromeres and are being pulled to opposite poles of the cell ( one sister to one side)
By the end of anaphase each pole will have a complete set of chromosomes
Explain what is telophase
Chromosomes being to uncoil and form chromatin
This action preaches the genetic material for directing the metabolic activities of new cells
The spindle breaks down and a nuclear membrane forms
Explain what cytokinesis is ..
Final stage where cytoplasm splits into 2 and the cell divides
This dictions occurs when the plasma membrane of the parent cell pinches inwards along the cell’s equator until 2 daughter cells form
What are spindle fibres?
If is a cytoskeletal structure of eukaryotic cells that forms during cell division to seperate sister chromatids between cells.
What is a centromere?
Specialised DNA sequence of a chromosome that links a pair of sister chromatids.
What are centrioles?
Organelles in cells involved in the development of the spindle fibres in cell division
What are Chromatids?
They are chromatin split in half and the centromere is the thing that connects an air of chromatids in their centres.
What is meiosis?
Meiosis is a type of cell division in sexually reproducing organisms and produces variations in the gametes.
Variation in the gametes ensures higher survival rates in the human population.
46-92- 2x46 - 4x23
How does Variations occur?
Jumbling of chromosomes each time a female is produced. The combinations in which the chromosomes are divided up into unique in each gamete.
Another way is through crossing over where a section of 1 chromosome is transferred to male chromosomes or visa versa.
How does Fertilisation occur?
2 Haploid gametes (1sperm and 1egg) fuse together and forms a diploid Zygote which contains 23 maternal and 23 paternal chromosomes.
From there the fused Zygote grows through the process of mitosis.
