Bio Sem 2 Unit - Topic 2 = Reproduction and Inheritance Checklist Flashcards
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Define Asexual reproduction
requires only one parent and produces genetically identical offspring
Describe binary fission
An organism duplicates its genetic material and then divides into two parts (cytokinesis) with each organism receiving one copy of the DNA.
Describe fragmentation
A piece of an organism breaks off and the piece grows to form another organism with the same DNA as the original
Describe budding
- Small bud grows out of parent
- Two different sized structures made (with identical
DNA) - Bud can breaks off and grow into new organism
- Yeast and hydra reproduce by budding
Describe vegetative propagation
- A form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures
- Plants can do this naturally through the production of runners
Identify the advantages and disadvantages of asexual reproduction
Advantages
- Asexually reproducing populations grow faster - good for organisms that are fine-tuned to the environment.
- Does not require an organism to find a mate to reproduce.
- Requires very little parental investment and removes the need to protect fragile offspring.
Disadvantages
- Genetic diversity is low and asexually reproducing populations may suffer during rapid environmental change.
Define Cloning and clones
Cloning produce genetically identical individuals, otherwise known as a clone.
Clone is a geneticly identical offspring of a parent
Process of SCNT to produce clones
Somatic cell is taken out of animal A –> the nucleus of the somatic cell is taken out –> the donor egg cell is taken out from animal B and it’s nucleus is removed –> the nucleus from animal A is inserted into the empty egg from animal B by enucleation –> the new egg is than placed into the Surrogate mother.
Issues associated with reproductive cloning technologies
- Animal suffering
- Human cloning
- Premature ageing
- safety and efficiency
- Cost per cloning
Define sexual reproduction
Reproduction of 2 organisms who combines their genes (23 from male + 23 from female) to produce genetically diverse offsprings
Describe the general steps of sexual reproduction
Sperm from the male which has 23 chromosomes combines with egg from the female which has 23 chromosomes to produce genetically diverse offsprings
Importance of meiosis in sexual reproduction
Meiosis is important in sexual reproduction as it creates genetic diversity in the offsprings produced by dividing 2 times and mixing the genes together
How are chromosomes divided during the two stages of meiosis
In the first stage of meiosis, the chromosomes undergo ‘cross-over’ (DNA exchange) then chromosome halving to produce 2 non-identical daughter cells
In the second stage of meiosis, the chromosomes divide again to produce 4 non-identical cells
Define Haploid and Diploid
Haploid - A cell that contains a single set of chromosomes. Example = Gametes
Diploid - A cell containing two copies of each chromosome. Example = body cells
What events increase genetic diversity in meiosis and how?
‘Cross over’ in M-phase 1 exchanges DNA from male and female chromosomes combined with cell halving leading to 2 non-identical daughter cells
Cell division in M-phase 2 halves the cell’s chromosome again which further increases the genetic diversity leading to 4 non-identical daughter cells
