sexual reproduction

sexual reproduction is when offspring are produced by two organisms, a male gamete (sperm cell) fertilizes a female gamete (egg cell). in simpler terms, sexual reproduction is when a male organism and a female organism come together to make an offspring. there are disadvantages and advantages to sexual reproduction. the disadvantages to sexual reproduction is that you need to find a mate, takes up a lot of  energy, fewer offspring, etc. the advantages to asexual reproduction is that all of the organisms are not the same thanks to meiosis which means that the same disease can’t easily kill all of the sexually reproduced organisms.

asexual reproduction

asexual reproduction is when a single organism produces offspring by itself, making an identical copy of itself. there are many ways that asexual reproduction is performed. the first way is binary fission, which is basically when a single cell organism like bacteria split in half to make an identical copy of itself. the other way that asexual reproduction occurs is by budding, which is when offsprings are produced by the parent and the organism produces an organism that grows on the main organism which then breaks off to create another organism entirely. the next method of asexual reproduction is fragmentation which is when a organism’s body part breaks off, which then creates a whole new organism, an example is a star fish. the other asexual reproduction method is vegetative reproduction which is when an organism like a strawberry or potato, produces another organism that detaches form the parent plant and becomes another organism. the last method of asexual reproduction is spore formation which is basically when an organism breaks up into many pieces then those pieces become a copy of the original parent spore. now that we have talked about the methods of asexual reproduction, there are also advantages and disadvantages to to asexual reproduction. the advantages to asexual reproduction is that it takes little energy, you don’t have to find a mate, you produce many offspring at a time, etc. the disadvantages to asexual reproduction is that because all of the organism that are produced are identical copies, they can be easily killed by the same disease, the other reason is because there is no difference/variety.

mitosis

mitosis is a part of the cell cycle where cells split to create more cells to make more cells or to replace the cells that have died/are damaged. mitosis is the shortest stage of the cell cycle. there are a few steps to mitosis which is easily memorized by PMAT, prophase, metaphase, anaphase, and telophase. prophase is when the nucleus disappears and spindle fibres attach to the chromosomes in the cell. metaphase is when the spindle fibres line up the chromosomes on the equator of the cell. anaphase is when the spindle fibres pull the sister chromatids to the opposite poles of the cell. is the last phase, telophase, the spindle fibres disappear and a nuclear membrane forms around each set of chromosomes.

meiosis

meiosis is how the body makes gametes (sperm and egg cells). a male body keeps producing sperm cells thought his life time, however this is not what occurs in female bodies because female bodies are born with millions of egg cells. gametes have 23 chromosomes because when they meet the other half which would be a egg cell and a sperm cell then it will equal to 46 chromosomes, creating an organism with half of the chromosomes from one parent and the other half of chromosomes from the other parent. meiosis also has multiple stages, they have PMAT 1 and PMAT 2. PMAT 1 is prophase 1, metaphase 1, anaphase 1, and telophase 1. PMAt 1 and PMAT 2 are not the same things. in prophase 1 homologous chromosomes pair up, and non-sister chromatids exchange genetic material, this process is called crossing over. in metaphase 1 homologous chromosomes pair up at the equator of the cell. in anaphase 1 homologous chromosomes separate and are pulled to opposite poles by the spindle fibres. in telophase 1 one chromosome from each homologous pair is at each pole of the cell. now we are going to be moving on to PMAT 2. in prophase 2 there is one chromosome of the homologous pair up in each cell. in metaphase 2 the x-shaped chromosomes form a single line across the middle of the cell. in anaphase 2 sister chromatids move to opposite poles of the cell, and once they separate, each sister chromatid is considered to be a chromosome. in the final stage of meiosis, telophase 2, spindle fibres begin to disappear, and a nuclear membrane forms around each set of chromosomes.

comparing mitosis and meiosis

mitosis and meiosis are somewhat similar, but there are many differences, so here are some of those differences. the first difference is that in meiosis non-sister chromatids exchange genetic material via crossing over which is not a something that is done in mitosis. another difference is that in meiosis the cell has to divide 2 times but in mitosis the cell only has to divide once. another difference is that meiosis is used for genetic material like gametes, but mitosis is for regular body cells. there are many differences between mitosis and meiosis but these were just a few.

how organisms grow

organisms grow by producing cells over and over and over again. they keep doing this to grow in size. the way cells are produced in by mitosis. however, for mitosis to work the cells need to meet some requirements.  the first requirement is that the cell can’t be damaged at all, or else the cell can’t split. the second requirement is that the cell must have enough nutrients. the last requirement is that the DNA inside the cell’s nucleus must be replicated.

 

 

sources:

info – what Mr.Robinson taught me

first picture – https://www.knowswhy.com/similarities-between-sexual-and-asexual-reproduction/

second picture – https://en.wikipedia.org/wiki/Mitosis

third picture – https://en.wikipedia.org/wiki/Meiosis