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Explore the process of meiosis, which produces haploid gametes or spores. Learn about the similarities and differences between meiosis and mitosis. Discover the production of sperm and egg through spermatogenesis and oogenesis. Understand the concepts of sexual and asexual reproduction, including their advantages and disadvantages. Explore different life cycles, such as haploid and diploid stages, and the alternation of generations.
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Chapter 7.1 Meiosis
Let’s make a sex cell! • Meiosis – Production of haploid gametes or spores. • Meiosis is very similar to mitosis with four distinct differences. The same phases are used as in mitosis only they are run through twice without interphase in the middle. In metaphase I the chromosomes line up next to each other. Meiosis produces haploid cells Meiosis results in four cells
Making Sex Cells • Meiosis involves the production of sex cells, namely the sperm and egg. • The production of sperm in men is known as spermatogenesis. • The production of an egg (a.k.a. an ovum) in women is known as oogenesis. • Meiosis in males results in 4 sperm cells whereas meiosis in females results in only 1 egg
Chapter 7.2 Sexual & Asexual Reproduction
Asexual Reproduction • Asexual Reproduction – Type of reproduction that only involves one parent passing all of its genes to the offspring. • Individuals produced by asexual reproduction are called clones. • Clone – an organism that is genetically identical to its parent. • Examples of this are fission, fragmentation or budding.
Sexual Reproduction • Sexual Reproduction – is when two parents form haploid reproductive cells which join to form an offspring. • Sexual Reproduction occurs in eukaryotic cells. • What are some positives and negatives of sexual reproduction and asexual reproduction?
Life cycles • Haploid L.C. – Most of these organism’s life is spent in the haploid stage. Eg protists and algae. • Diploid L.C. - Most of these organism’s life is spent in the diploid stage. Eg. Animals. • Alternation of Generations – Organisms like plants spend part of their lifetime as a haploid cell and the other part as a diploid.
Alternation of Generations • The diploid phase that produces spores is called the sporophyte. • The gametophyte is the haploid stage that produces gametes. • The sporophyte undergoes meiosis which will produce spores that will eventually come together to form a zygote.