Gen-Bio-2-Reproduction (2).pdf

General Biology 2  Response to different stimuli include many processes in plants and animals such as: Reproduction And Development Chemical And Nervous Control Nutrition Immune Systems Gas Exchange...

General Biology 2  Response to different stimuli include many processes in plants and animals such as: Reproduction And Development Chemical And Nervous Control Nutrition Immune Systems Gas Exchange Sensory And Motor Transport/Circular Mechanism Regulation Of Body Fluids  Asexual Reproduction in Plants There are different types of asexual reproduction in plants that give rise to Offspring genetically similar with their parent, hence, are clones of parents.  Asexual Reproduction in Plants Vegetative reproduction requires a fragment of the plant produced from budding and tillering. In this type of reproduction, structural modifications of the stem or roots and a few species leaves are involved.  Asexual Reproduction in Plants Vegetative reproduction requires a fragment of the plant produced from budding and tillering. In this type of reproduction, structural modifications of the stem or roots and a few species leaves are involved.  Asexual Reproduction in Plants Types of vegetative Propagation: 1. Natural 2. Artificial 1. Tubers Spider Plant  Asexual Reproduction in Animals Asexual reproduction has several potential advantages. For instance, it enables animals living in isolation to produce offspring without locating mates. It can also create numerous offspring in a short amount of time, which is ideal for colonizing a habitat rapidly.  Sexual Reproduction in Plants All plants reproduce via ALTERNATION OF GENERATIONS, a reproductive life cycle where offspring alternate between diploid and haploid varieties. - Most plants undergo an alteration of the generation having two multicellular phases, the gametophyte, and the sporophyte. Sporophytes consists of roots, shoots, leaves, having the diploid state of reproductive structure that eventually produces the gametophyte. Gametophytes contain a haploid number of chromosomes giving rise to the male or female gametes or both. - Flowering plants have highly reduced male and female gametophytes, called pollen grains and embryo sacs. PARTS OF A COMPLETE FLOWER 1. Sepals- an accessory part that protects the inner parts of the flower in the bud, collectively known as calyx. 2. Petals- usually bright colored structure found lying inside the sepals, collectively called corolla. Their color and aroma attract pollinators such as insects and birds. 3. Stamen- commonly known as the male reproductive organ found surrounded by the petals. It consists of a filament or stalk where the anther that holds the pollen attaches to its highest point. 4. Pistil - commonly known as the female reproductive organs where the ovary is located. A stalk called style protrudes from the ovary and at its apex is a slight enlargement, known as the stigma, that receives the pollen. 5. Receptacle- structure that holds all organs of a flower. Types of flowers based on the presence of the whorls: A. Complete - is a plant biology term that is used to describe a flower that is built with four parts which include the sepals, petals, pistils, and stamens. Types of flowers based on the presence of the whorls: B. Incomplete -If any of the sepals, petals, pistils, and stamens, which are integral in forming a flower, is missing, a flower is called an incomplete flower. Types of flowers based on the presence of the reproductive whorls: A. Perfect/Bisexual – is one in which both male and female reproductive structures are present. Both androecium (whorl of stamens) and gynoecium (whorl of carpels or pistil) are located on the same flower. Example: Roses, Sunflower, Hibiscus, Lily Types of flowers based on the presence of the reproductive whorls: B Imperfect/Unisexual -flower that does not have both male and female structures. 1. staminate flower (male) 2. carpellate/pistillate flower (female) Examples: squashes, cucumbers, corn, and grasses  Sexual Reproduction in Animals Sexual reproduction increases genetic variability (one of its advantages over asexual reproduction) among offspring by generating unique combinations of genes inherited from two parents.  Fertilization The fusing of the male and female gametes to form a zygote  Internal Fertilization The male generally delivers sperm cells directly into the body of the female. Her moist tissues provide the watery medium required for movement of sperm. Examples: Most terrestrial animals, few fish and some other aquatic animals  External Fertilization Mating partners usually release eggs and sperms into the water simultaneously. Examples: Many fish, amphibians, and other sexual aquatic animals use external fertilization (the exceptions are aquatic mammals, sharks, and some other special types of fish)