The flashcards below were created by user
on FreezingBlue Flashcards.
Difference between sexual nad asexual reproduction
Asexual reproduction is when a single parent passes copies of all its genes to its offspring. Sexual reproduction is when two parents give their offspring a unique combination of their own genes to create genetic variation
Difference between somatic cell and gamete
Gametes are cells that are involved in reproduction that transmit genes from one generation to the next. Somatic cells are any cells other than those involved in gamete formation
How are chromosomes arranged in Eukaryotic cells
Chromosomes are arranged as homologous pairs in eukaryotic cells
Difference between autosomes and sex chromosomes
Sex chromosomes are the X and Y chromosomes, which mainly determine gender. Autosomes are every other chromosome.
Why are gametes protduced my meiosis?
Gametes must be produced through meiosis because in sexual reproduction two gametes are united to form a diploid cell. If the gametes didn’t reduce their chromosome number to haploid, during sexual reproduction the offspring cell would have double the diploid number of chromosomes
how does meiosis compare with mitosis?
- In Meiosis: there is one replication of DNA before meiosis I begins; there are two divisions that goes through PMAT; there is synapsis of homologous chromosomes during prophase I; four, haploid, and unique daughter cells are produced; and in animals, the daughter cells are used to make gametes.
- In Mitosis: there is one replication of DNA during interphase; there is one division that goes through PMAT; there is no synapsis of homologous chromosomes; two, diploid, and identical daughter cells are produced; and in animals, it is used to enable a zygote to grow into an adult, produce cells for growth, repair, and also asexual reproduction.
Stages of Meiosis I
- Prophase 1: Chromosomes condence, crossing over occurs during synapsis, synapsis ends during prophase each homologous pair has one or more chiasmata (points of cross over), nuclar envelope breaks down, and the microtubules from one pole attach to the two conetochores
- Metaphase 1: pairs of chromosomes line up along the plate, and both chromatids are attached to conetochor fiber
- Anaphase 1: breakdown of proteins allows homolouges to seperate, the homolouges move toward the opposite poles
- Telophase and cytokinesis: the cytoplasim divides with the cell, cleavage furrow
Stages of Meiosis II
the division of a prokaryotic cell into two different offspring cells
Elaborate on the above diagram
- G1, s, G2 are all part of the interphase. INTERPHASE is the time between cell division,
- G1: Offspring grows to mature size
- S: DNA is copied (Synthesised)
- G2:Time in which the cell prepairs to divide
- Mitosis, Cell division
the first stage of mitosis, first the nucleus dissapears and centrosomes appear next to the nucleus. In animal cells the centrosome has centriols. in both plant and animal cells the centrosomes move toward the opposit ends of cell. Then spindle fibers are created and span from end to end but to not touch the chomosomes.
the second phase of mitosis. During this phase the chromosome line up along the middle of the cells and are held by the spindle fibers
the chromatids of each chromosome begin moving toward the oppisite ends of the cells.
- the chromosomes reach the oppisite ends of the cells and the spindle fibes dissasemble and the chromosomes return to chromatin and a nucear envelope forms.
- In animal cells a cleavage furrow is formed.
In plant cells the cell plate forms andin both animal and plant cells the cells seperate.
uncontrolled growth of cells.
transmit genes from one generation to the next
Group of 4 chromosomes