Types Of Sexual Reproduction PDF
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Uploaded by TriumphalSulfur5730
St. Jerome's University
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This document describes the different types of sexual reproduction in animals and plants. It covers topics such as fertilization, cleavage, and the formation of an embryo in both animals. In plants, the document explains pollination and fertilization, as well as the role of male and female gametes.
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Types of Sexual Reproduction Sexual Reproduction in Animals Occurs from specialized sex cells called gametes. Male gamete: sperm cells Female gamete: egg cells (ova) 1. When a sperm and egg cell meet (during mating)...
Types of Sexual Reproduction Sexual Reproduction in Animals Occurs from specialized sex cells called gametes. Male gamete: sperm cells Female gamete: egg cells (ova) 1. When a sperm and egg cell meet (during mating) it is called fertilization. 2. The cell that they create when joined is known as a zygote. → The zygote then splits into 2 cells. 3. The cells divide again and again in a process called cleavage. 4. Cleavage continues until we have a multicellular embryo. The new individual will be a mix of both parents. Sexual reproduction promotes variation! Sexual Reproduction in Plants Flowers and plants can reproduce sexually. Plants that reproduce sexually have gametes too! Male gamete: Pollen Pollen is found on the stamen. The stamen is the male part of the plant. Female gamete: Ovules Ovules are found in the pistil. The pistil is the female part of the plant. Pollination Vs. Fertilization Pollination occurs when pollen is transferred from the anther of the stamen to the stigma of the pistil. Fertilization occurs when the male and female gametes meet. Cross-pollination happens when pollen of one plant is carried to the stigma of another plant. 🡪 by birds, bee, etc. Cross-fertilization happens when a grain of pollen from another plant produces a tube that grows down the style into the ovary of the plant. The pollen grain and ovule meet and a zygote forms. The zygote then begins many divisions to become an embryo. In most plants the embryo is encased in a seed. Cross-fertilization will give the plant characteristics from both parent plants. Plants can self-fertilize. BE AWARE: Pollination and cross-pollination are ONLY the TRANSFER of pollen. This may not result in an embryo if no fertilization occurs. WATCH IT! SEXUAL REPRODUCTION ADVANTAGES DISADVANTAGES Advantages of Sexual and Asexual Reproduction Sexual Reproduction Asexual Reproduction -Allows for lots of -Does not require any variation specialized cells -Protects species from -Doesn’t need gametes environmental wipeouts to merge (extinction) -Can be very fast Disadvantages of Asexual and Sexual Reproduction Sexual Reproduction Asexual Reproduction -Takes a long time -No variation -Takes a lot of energy -More likely for environmental wipeout Asexual and Sexual Reproduction Reproduction and Variation Reproduction creates new individuals of a species. The type of reproduction decides on the level of variation in individuals. There are 2 types: → Asexual Reproduction → Sexual Reproduction TYPES OF ASEXUAL REPRODUCTION Watch it! Binary Fission ONLY occurs in one-celled organisms. Ex. Amoebas, some bacteria Cell splits exactly in two 🡪 2 identical copies Budding Occurs in yeast, coral, hydra, etc. The organism creates a “bud”, a small version of itself. Sometimes this detaches, sometimes it stays attached. Spore Reproduction Occurs in fungi, moulds and plants like ferns. Spores are produced- they are similar to seeds but are made by division of parent cells, not by the union of 2 cells. Individuals produce MANY spores. Vegetative Reproduction Most plants can do this. Used by potatoes, tulips, etc. Needs no seed formation. Cuttings, runners, and rhizomes are all examples. ASEXUAL REPRODUCTION ADVANTAGES DISADVANTAGES A Closer Look at Variation Unit A- Section 2.1 Variation is the Spice of Life! Scientists study variation very closely. They look at: → How characteristics are passed from one generation to the next → How characteristics show up in individuals → How environment affects variation Heritable and Non-Heritable Characteristics Heritable Characteristics: Passed from generation to generation. Inherited from parents. Non-heritable characteristics: Not passed to offspring. Also known as acquired characteristics. Sort Them! Flower Petal Colour Hair Colour Height Heritable Sickle Cell Anemia Scars Widow’s Peak Non- Heritable Ability to Roll Tongue Eye Colour Ability to Juggle Ability to Golf HeritableHave Discrete characteristics: andanNon-Heritable either/ or option (or a limited amount). Characteristics Continuous characteristics: Many different options for the trait. Could be placed on a spectrum. Sort Them! Hand Size Hair Colour Height Discrete Sickle Cell Anemia Eye Colour Dominant Hand Continuous Ability to Roll Tongue Skin Tone Ear Lobe Attachment Ability to Golf Drank caffeine often 4’10” 4’8” 5’11” 5’1” 5’3” Very Variation and the Environment healthy smoker Certain traits can be inherited but ALSO affected by the environment. Height can be affected by nutrition or sleep patterns. The amount of sunlight a tree has affects how it grows. Adorable. Check and Reflect! Page 29 #1-5 Label the heading of your notes with: A2.1 A Closer Look at Variation Vari Wti Spe How mer t sa pi b iffn? Varit All species vary slightly. The differences between members of the same species is called variability. Wh i val imt? When the environment of a species changes variability can save a population. Bacal Camag Resne Cha n epur Abiy e difft o Nat Selon Natural selection occurs when an environment “selects” which individuals will survive long enough to reproduce. Che n Rle Page 24- #1-4 Inedde Reloss All living creatures rely on other creatures for survival. There are many types of relationships. Examples? SBI ▶ When animals of different species do things to or with each other it is called symbiosis. ▶ 3 types: Commensalism Mutualism Parasitism 1 organism benefits from Both organisms benefit 1 organism benefits and the an interaction the other from the interaction. organism is harmed. does not. The organism NOTE: This is not that does not benefit it not predation. harmed. a. commensalism b. mutualism c. parasitism a. commensalism b. mutualism c. parasitism a. commensalism b. mutualism c. parasitism a. commensalism b. mutualism Barnacles, unable to move on their own, attach themselves to whales to increase their c. parasitism chances of finding food. Whales are not affected by barnacles. a. commensalism b. mutualism The sea lamprey attaches itself to other fishes by suction. Some of the lamprey’s victims may c. parasitism die, while others live but have a scar where the lamprey attached itself. a. commensalism b. mutualism As the Monarch butterfly feeds, pollen sticks to its body. The butterfly carries the pollen to the c. parasitism next flower it feeds from. Most flowers need this pollen to produce seeds. Ineses Cti When more than one species needs the same resources we end up with interspecies competition. Why is this a problem? Nic A niche is the role of an organism in its ecosystem. This includes: → What it eats → What eats it → Habitat → Effect on other populations → Effect on environment Rese Prin ▶ Sometimes, species divide up a shared resource. This COULD cause problems. ▶ Species can avoid this by having different behavioural patterns that allow them to share the resource. Rev Quto in your notes
