Gen Bio 2 Page 16: Angiosperm Reproduction Summary

Angiosperm Reproduction

• Alternation of generation occurs between diploid sporophyte and haploid gametophyte generations
• Meiosis in the diploid sporophyte produces haploid spores
• Haploid spores give rise to the haploid gametophyte generation
• Microspores undergo mitosis to produce pollen grains containing tube cells and generative cells
• Tube cells produce the pollen tube, while generative cells produce two sperm nuclei
• Pollen grains are the male gametophyte, while sperm nuclei are the male gamete
• Megaspores undergo meiosis to produce one surviving megaspore, which becomes the female gametophyte
• Egg cells are the female gamete

Pollination

• Abiotic vectors include non-living things like water and wind
• Biotic vectors include living things like bees, birds, and insects

Fertilization

• Double fertilization event involves one sperm fusing with the egg to form a zygote, and another sperm fusing with the endosperm mother cell to form a triploid endosperm
• Sperm + egg = zygote (2n)
• Sperm + endosperm mother cell = endosperm (3n)

Embryo and Seed Development

• Seed consists of an embryo, endosperm, and seed coat
• Endosperm nourishes the developing embryo
• Embryo grows, producing one or two cotyledons

Fruit Development

• Non-essential flower parts fall off after fertilization
• Hormones influence the ovary to develop into a fruit
• Achene is a type of fruit where the seed is part of the fruit

Classical Genetics

• Gene is a portion of DNA that encodes a protein
• Alleles are variations of a gene
• Chromosomes are long strands of DNA associated with proteins
• Chromosomes come in homologous pairs, with one set from each parent
• Traits are determined by genes on the chromosomes
• Genotype is the actual gene makeup, while phenotype is the physical appearance
• Humans have 46 chromosomes or 23 pairs

Human Digestive System

• Peristalsis involves waves of contractions to move food along the digestive tract
• Muscular sphincters control movement from one compartment to another
• Digestion begins in the mouth with teeth breaking down food and salivary glands producing saliva
• Epiglottis prevents food from entering the trachea
• Stomach stores food, mixes it with gastric juice, and turns it into liquefied chyme
• Hydrochloric acid in the gastric juice kills microorganisms and denatures proteins
• Small intestine is the main site of digestion and nutrient absorption
• Villi and microvilli absorb products
• Pancreas supplies enzymes to break down macromolecules
• Liver produces bile to emulsify fat and aid in lipid digestion
• Gall bladder stores and releases bile

Large Intestine

• Large intestine absorbs water and remaining nutrients
• Material remaining after absorption in the small intestine passes to the large intestine

Nutrition

• Essential organic nutrients are required for growth, maintenance, reproduction, and repair
• Components of food necessary for all living beings include carbohydrates, fats, vitamins, and minerals
• Plants make their own food, while animals cannot
• Autotrophs produce their own food, while heterotrophs obtain energy from outside sources

Nutrition in Plants

• Autotrophic nutrition involves producing their own food
• Heterotrophic nutrition involves obtaining energy from outside sources
• Photosynthesis is the process of making food using light energy

Photosynthesis

• Stages of photosynthesis include light-dependent and light-independent reactions
• Light-dependent reactions occur in thylakoid membranes and convert solar energy to chemical energy
• Light-independent reactions occur in the stroma and use ATP and NADPH to reduce CO2 to glucose
• Oxygen is a byproduct of photosynthesis

Animal Nutrition

• Digestive system derives energy and raw materials from food
• Activities of the digestive system include ingestion, propulsion, and digestion
• Ingestion involves taking food into the alimentary tract
• Propulsion moves the contents along the alimentary tract
• Digestion involves mechanical and chemical breakdown of food