- Asexual reproduction is naturally how clones are formed. Clones are used in agriculture and research in order to develop dissed organisms, tissues and genes. Budding, fragmentation, vegetative reproduction, and spore formation are all types of asexual reproduction. One organism that reproduces by budding is bacteria and yeast. An example of fragmentation is annelid worms, mitochondrial eukaryotic. Organisms that use Vegetative reproduction are plants and crops such as corn, apples, mangoes and avocados. organisms that reproduce by Spore formation: Eukaryotic organisms, plants, algae,
and fungi. Some advantages of asexual reproduction are, large numbers of offspring are produced very quickly from one parent. Another advantage is that energy is not required to find a mate. And lastly large colonies form that will out-compete other organisms. Some Disadvantages of asexual reproduction is when you have one negative mutation, it can affect the whole offspring and can destroy large numbers of offspring because they are all genetic clones. Another is the fact that uncontrollable conditions such as extreme temperature change can wipe out entire colonies.
- The production of a new living organism by putting together genetic information from two different individuals (male/Female). One individual (male) produces a small gamete that travels to fuse with a larger gamete produced by the other (female). What sex a baby will be is decided when the egg and sperm meet. Each egg and each sperm have one sex chromosome. There are two kinds of sex chromosomes X and Y. Eggs carry only an X and sperm carry either an X or a Y. X+X means the cell will develop into a girl. X+Y means that it will develop into a boy. Once you are born, you will grow up into a unique human being there’s no-one else like you in the world. Even identical twins are not exact copies of each other they each have their own personalities.
Mitosis; a process that divides and genetically copies cells. ( 4 stages/ PMAT)
- The replicated chromosomes coil up into x-shaped chromosomes.
- the nucleolus will disappear
- the nuclear membrane will begin to break down
- spindle fibers begin to form
- the spindle fibers complete forming
- chromosomes attach to the spindle fibers
- the spindle fibers pull the X-shaped chromosomes into a single line across the equator of the cell
- spindle fibers begin to contract and shorten pulling the chromosomes apart
- the sister chromatids move to opposite poles of the cell
- once separated there are all considered chromosomes
- there is a new complete set of chromosomes at each end of the cell
- spindle fibers disappear
- nuclear membrane reappear around each set of chromosomes
- a nucleolus appears the cell can now divide.
- MEIOSIS I: Pairs of chromosomes are lined up at the center of the cell and then pulled to each side. Meiosis is a bit different than mitosis because there something called crossing-over happens with the DNA. This crossing over is an exchange of genes. Normally the cell would begin to go about and slowly duplicate the chromosomes for another mitosis division. Since this is meiosis, there is a very short interphase and division begins again.
- MEIOSIS II: In Prophase II the DNA that remains and the cell begins to condense. Each chromosome pair has a centromere. The centrioles also begin traveling to opposite sides of the cell. In Metaphase II all of the chromosomes line up along the center of the cell for duplication. Anaphase II, the chromosomes split and move to opposite sides of the cell. Each one splits into two pieces. They don’t divide up the DNA between the new cells; Each daughter cell will get one-half of the DNA needed to make a fully working cell.
Pollination; pollen is a substance that is powdery typically yellow, it is discharged from a male plant. pollen is transferred by bees, hummingbirds, moths, the wind, flies, and people.
Fetal development; Embryonic development is the stage that occurs before the fetus begins to develop. (There are 3 trimesters or stages)
- The first trimester; developing an organ system. Time from fertilization= 8 weeks. length of embryo/fetus= 9cm
- The second trimester; growth of the fetus, time from fertilization= 12-16 weeks. Length of fetus= 35cm
- The third trimester; continued growth of the fetus, time from fertilization= 32 weeks, length of fetus= 40-50cm.
External Fertilization; Through a process called spawning a male and female fish would release their sperm or egg cells that unite outside their bodies. When the sperm cell reaches the egg cell that’s when the fertilization has begun. This process is normally common with underwater species.