Untitled Flashcards Set

1. Describe the structure of a flower.  Where do megasporangia and 

microsporangia occur within the floral structure?

• A flower is a reproductive shoot, stem branch that produces reproductive organs instead of leaves, composed of concentric whorls of floral organs, typically having an outer ring of sepals. Sepals protect the flower in development. Inside of sepals are petals, which attract pollinators to the flower. Inside of petals are stamens which are composed of filament and anthers. Anthers are microsporangia-microspore mother cells which undergo meiosis to produce 4 microspores which develop into pollen grains through mitosis. Inside stamens are carpels fused and called pistils, each carpel contains an ovary which in turn contains one or more ovules. Ovules are megasporanigia-megaspoer mother cells which divide by meiosis to produce 4 megaspores 3 die, leaving one. Divides mitotically to form the female gametophyte housed in the ovule. 

2. Describe the structure of the male and female gametophyte stage in flowering plants.

• A male gametophyte (pollen grain) develops in the anthers of the flower, the microspore mother cell goes through meiosis 1 and produces 2 gametophytes then goes through meiosis 2 and produces 4 male gametophytes haploid microspores. Spores divide through mitosis to form a tube cell and generative cell. This becomes a two cell gametophyte or a cell within a cell. After meiosis 2 the gametophytes secrete a tough outer coat to form pollen grains. The pollen grain is then released by the anther to land on the stigma of another flower. Landing on stigma triggers mitotic division of generative cells forming two sperm cells. Female gametophytes develop in ovules of the megaspore, by mitosis of the megaspore and contain an egg cell, 2 synergids to support the egg, 3 antipodal cells, and  2 haploid nuclei. 

3. Describe the process of double fertilization in flowering plants. What happens to the two fertilized cells

• 2 sperm cells in the pollen tube allow for double fertilization, one fuses with the egg and the other with the central cell to form a triploid cell which divides to form endosperms. Two sperm cells from pollen grain fuse with two female cells within the ovule.

4. What are six levels of biological organization?  Describe each level, and explain how the concept of emergent properties applies to this list.

• Molecular, cellular, tissue organ, organ system, and organism. Molecular is the chemical component that makes up the cell. Cellular is the fundamental unit of life that can exhibit specialization or differentiation. Tissues are cells of a particular type coming together to provide a specialized function. Organs are structural arrangements of two or more tissues specialized to perform a specific function. Organ system is a group of organs working together to perform a certain function in an organism's body. Organisms are a complete set of interacting organ systems that together exhibit the characteristics of life. These are emergent properties because the smaller parts that are emergent in the larger parts but not in the smaller parts.

5. What are four common animal tissues, and what are their key characteristics?

• Muscle, Nervous, epithelial, and connective tissues. Muscle tissue is the capacity to contract, there are 3 types of muscle tissue, skeletal, smooth, and cardiac. Nervous tissue specialized tissue that controls and regulates body activity by transmitting information in the form of electrical impulses. Epithelial tissue is coverings on all external and internal surfaces of the body cavities and hollow organs, major tissue in glands. Connective tissue has diverse forms and provides diverse function, provides solid support, cushions and insulators, mechanical strength, and mechanical forces.

6. Name and briefly describe seven types of epithelial tissue.

• Seven types of epithelial tissue are simple squamous, simple cuboidal, simple columnar, transitional, stratified cuboidal, stratified squamous, pseudostratified columnar. Simple epithelia are composed of single layers of cells. Stratified are composed of multiple layers. Squamous epithelia are composed of cells that are flattened or scale-like. Cuboidal epithelia are cube-like. Columnar epithelia are composed of cells that are column shaped. Transitional epithelium changes shape when stretched which exhibits squamous shape and when relaxed it exhibits cuboidal shape. 

7. Describe the difference between intracellular and extracellular fluids, and between interstitial fluid, plasma and hemolymph.

• The difference between extracellular and intracellular is that extracellular is fluid that is outside of the plasma membrane, intracellular is fluid that is inside of the plasma membrane. Interstitial fluid is extracellular fluid that bathes cells in tissues, plasma and hemolymph are extracellular fluid found in vessels in animals. Hemolymph is the circulatory fluid in invertebrates and insects bathes tissue similarly to blood in vertebrates. 

8. Describe the digestive functions that are provided by the oral cavity and stomach

• Oral cavity has dentition (teeth) and tongue aids in breaking food into smaller pieces and swallowing. Salvia released by salivary glands lubricates food to facilitate swallowing, dissolves food to facilitate taste and increases accessibility to digestive enzymes lysozyme enzyme of polysaccharides with salivary amylase enzyme.  The stomach is a sac-like organ used for storing food and digestive function. Mechanical disruption of food partially digests proteins, and hydrochloric acid kills bacteria microbes dissolves/denatures proteins and pepsinogen is converted to pepsin when in stomach acid environment begins protein digestion. Stomach churns protein into liquid chyme. Stomach muscles then empty it out into the small intestine.

9. Describe the digestive functions provided by the small intestine 

• Digestion and absorption, carbohydrate digestive enzymes found attached to the inner luminal of the small intestine called brush border enzymes carboxypeptidase removes amino acids from the carboxyl group. Aminopeptidase removes one amino acid at a time at the amino end. Dipeptidase splits dipeptides into separate amino acids.Finger-like projections called villi which maximizes surface area and aids in absorption.

10.  Describe the organs and digestive contributions of the accessory organs of the mammalian digestive system

• Liver produces bile to emulsify fats, and pancreas has crucial zymogen protein digestion enzymes also has active enzymes secretes enzymes to breakdown. Gallbladder releases bile and emulsification fatty material not soluble in water bile salts help break down insoluble fat globules into smaller insoluble fat globules Bile salts have hydrophobic and hydrophilic ends called amphipathic no bile salts would cause biolescents

11. Identify the locations and enzymes and enzyme sources that provide for carbohydrate digestion in the human digestive system

• Begins in the oral cavity with action of salivary amylase which breaks things down to smaller pieces. Not much happens in the stomach, In lumen of small intestine polysaccharides turn into maltose and disaccharides catalyzed by pancreatic amylase. Epithelium of the small intestine turns disaccharides into monosaccharides by brush border enzymes.

12. Identify the locations and enzymes and enzyme sources that provide for protein digestion in the human digestive system.

• Begins in the stomach with activity of pepsin proteins turn to small polypeptides and polypeptides break down to smaller polypeptides by pancreatic trypsin and chymotrypsin then pancreatic carboxypeptidase break down to amino acids then in the Epithelium of small intestine turns small peptides into amino acids through dipeptidase, carboxypeptidase, and aminopeptidase, Trypsinogen is activated to become trypsin and can now activate others different enzymes clip amino acid chains Brush border enzymes finish off cleavage.

13. Explain the significance of chylomicrons in the process of lipid absorption.

• Digested lipids are present as micelles in the small intestine coded with bile salts. Direct diffusion across the epithelial cell membrane-enclosed protein lipid package called chylomicrons acts as primary transport to peripheral tissues, don't go into the bloodstream taken up in by lymphatic system, called lacteals taken up in the central vessel called lacteal gets delivered into circulatory system.

14. Describe the processes by which the final digested products of carbohydrates and proteins are absorbed and enter into the bloodstream.

• Absorbed by secondary active transport Cotransport with ions moving down concentration gradients provides energy requirement for amino acid transport into intestinal epithelial cells Concentration in lumen is less than that in cells. Cotransport Protein brings amino acids moves an ion sodium in at the same time sodium is high on outside low on inside intentionally movies from high to low energetically favorable Monosaccharides absorbed by diffusion or secondary active transport none energy dependent Transport of glucose, galactose require energy provided by cotransport Released into interstitial fluid taken up by circulatory system capillaries to be delivered to other areas of the body