Biology 111 Exam 1: Key Concepts
If you pound a nail into a tree 1 meter off the ground and come back to find it in 20 years, it will be:
1 meter off the ground and more deeply embedded in the tree. Apical meristems elongate shoots through primary growth; therefore, the tree grows from the top. Lateral meristems add girth to woody plants through secondary growth; therefore, the tree would increase in diameter but the nail would not be elevated.
The three basic components of circulatory system:
1) A circulatory fluid (blood) 2) A set of interconnecting vessels 3) A muscular pump, the heart.
What are the two main types of buds, describe their function:
1) Apical buds- where most of the growth is concentrated near the top of the plant. Primary growth stems from this. 2) Axillary buds- Buds found in the upper angle formed by each leaf at every node. Lateral growth stems from this.
What are the 3 tissue types found in all plants?
1) Dermal 2) Vascular 3) Ground
What are the 3 basic steps of nephron filtration:
1) Glomerular filtration 2) Tubular reabsorption 3) Tubular secretion
List the main differences between Monocot & Eudicot plants: (6)
1) Monocots have 1 cotyledon/ Eudicots have 2 2) Monocots have parallel leaf venation/ Eudicots have net-like venation 3) The vascular tissue in monocots is scattered/ the vascular tissue in eudicots is arranged in a ring 4) Monocots have fibrous roots/ Eudicots have a taproot 5) Monocots have one opening in their pollen grain/ Eudicots have 3 6) Monocots have floral organs (petals) in 3s and 6s/ Eudiocts have them in 4s or 5s
List the 5 common cell types in plants:
1) Parenchyma 2) Collenchyma 3) Sclerenchyma 4) Xylem 5) Phloem
List the 3 "atypical" types of stems & describe each:
1) Rhizomes- Underground stems that grow horizontally (ex: Ginger) 2) Stolons- Stems that run along the surface of the ground and produce clones (ex: strawberries) 3) Tubers- Stems that are specialized to store food. (ex: potato; the eyes of a potato are actually clusters of axillary buds)
List the 4 basic plant organs:
1) Roots 2) Stems 3) Leaves 4) Reproductive structures.
List 4 adaptations/types of epithelial tissue:
1) Stratified squamous epithelium : protective barrier (skin, esophagus lining) 2) Simple cuboidal epithelium : secretion (kidney tubules) 3) Simple squamous epithelium : exchange materials by diffusion (blood vessels, lung lining) 4) Simple columnar epithelium : nutrient absorption (intestines)
List the "atypical" type of leaf & provide two examples:
1) Tendrils- modified leaves for support Ex: The spines of a cacti are the leaves, photosynthesis is carried out by the stems. Ex: Storage leaves- onions; the layers are leaves
All organisms require a standard set of _____ amino acids to make a complete set of proteins.
20
Describe a cuticle:
A cuticle is a waxy coating made of secretions of cutin that helps prevent water loss in non-woody plants.
What happens when your blood sugar is high?
A high level of glucose in the blood stimulates the pancreas to secrete insulin, a hormone that causes a decrease in the blood glucose level.
Relate Stomata and hormone:
A hormone called Abscisic acid (ABA) is produced in the roots & leaves in response to water deficiency and signals guard cells to close stomata. This response reduces wilting nut also restricts CO₂ absorption, thereby slowing photosynthesis.
Describe the organic and inorganic components of soil:
A soil's composition encompasses its inorganic (mineral) and organic chemical components. The organic components include the many life-forms that inhabit the soil. For inorganic components, the surface charges of soil particles determine their ability to bind many nutrients. Most soil particles are negatively charged, so positively charged ions (cations), such as potassium (K+), bind strongly to them. Negatively charged ions (anions), such as nitrate, are easily lost by leaching (when excess water is flushed through the soil). For organic components, the major organic components of topsoil is humus, the remains of dead organisms and other organic matter that acts as a great fertilizer. Humus prevents clay particles from packing together and forms a crumbly soil that retains water but is still porous enough to aerate roots adequately. Humus also increases the soil's capacity to exchange cations and serve as a reservoir of mineral nutrients.
What process contributes directly to the turgor pressure that opens and closes stomata?
Active Transport. Stomata open when guard cells actively accumulate K+ from neighboring epidermal cells.
Name the organs of the alimentary canal and any accessory organs attached to them. Tell which major events of digestion occur in each:
After food is chewed and swallowed, it takes 5-10 seconds for it to pass down the esophagus and into the stomach, where it is stored for 2-6 hours during the first stages of processing. Complete digestion and nutrient absorption occur in the small intestine over a period of 5-6 hours. Processing is completed in the large intestine, and undigested material is expelled through the anus as feces.
What plant cell types are alive/dead at maturity?
Alive: 1) Parenchyma 2) Collenchyma 3) Phloem Dead: 1) Sclerenchyma (sp.) 2) Xylem
Describe lateral meristems:
Allow growth in thickness ↔ provides cells for secondary growth. The vascular cambium adds layers for vascular tissue called secondary xylem (wood) and secondary phloem. The cork cambium replaces the epidermis with a thick, tough periderm (in woody plants).
Explain how one hormone can have very different effects on different tissues (using epinephrine):
Also called adrenaline, epinephrine is secreted by the adrenal glands, which lie on top of the kidneys. When you are in a stressful situation, perhaps running to catch a bus, the release of epinephrine rapidly triggers responses that help you chase the departing bus: raising the glucose level in the blood, increasing blood flow to muscles, and decreasing blood flow to the digestive system. In the liver, epinephrine binds to a β-type epinephrine receptor in the plasma membrane of target cells. This receptor activates the enzyme protein kinase A, which regulates enzymes of glycogen metabolism, causing release of glucose into the bloodstream. In blood vessels supplying skeletal muscle, the same kinase activated by the same receptor inactivates a muscle-specific enzyme. The result is smooth muscle relaxation, vasodilation, and hence increased blood flow. In contrast, intestinal blood vessels have an α-type epinephrine receptor. Rather than activating protein kinase A, the a receptor triggers a distinct signaling pathway involving different enzymes. The result is smooth muscle contraction, vasoconstriction, and restricted blood flow to the intestines.
Describe an essential element:
An element that is required to live, but is not produced by cells. It must be obtained from the environment.
Describe angiosperm reproduction:
Angiosperm reproduction involves an alternation of generations between a multicellular diploid sporophyte generation and multi-cellular haploid gametophyte generation. Flowers, produced by the sporophyte, function in sexual reproduction.
What do animal cells use fatty acids for?
Animal cells use fatty acids to produce cellular components that include membrane phospholipids, signaling molecules, and storage fats
Produces the pollen containing sperm:
Anther
Describe the two sides of epithelial tissues:
Apical and Basal The apical surface faces the lumen (cavity) or outside of the organ. The basal surface is attached to a basal lamina, a dense mat of extracellular matrix.
What are the two major "compartments" in plants? Describe them:
Apoplast -In an apoplastic route, water and solutes move along the continuum of cell walls and extracellular spaces. (externally) Symplast -In the symplastic route, water and solutes move along the continuum of cytosol. This route requires substances to cross a plasma membrane once, when they first enter the plant. (internally)
Channels in a cell for water to pass:
Aquaporins
Transport proteins that facilitate the diffusion of water across cell membranes:
Aquaporins
Distinguish between arteries, capillaries, and veins:
Arteries carry blood from the heart to organs throughout the body. Within organs, arteries branch into arterioles. These small vessels convey blood to capillaries, microscopic vessels with very thin, porous walls. Local networks of capillaries, called capillary beds, infiltrate tissues, passing within a few cell diameters of every cell in the body. Across the thin walls of capillaries, dissolved gases and other chemicals are exchanged by diffusion between the blood and the interstitial fluid around the tissue cells. At their "downstream" end, capillaries converge into venules, and venules converge into veins, the vessels that carry blood back to the heart.
Explain the impact of waste on osmoregulation & compare the types of waste in animals:
Because most metabolic wastes must be dissolved in water to be excreted from the body, the type and quantity of an animal's waste products may have a large impact on osmoregulation. When proteins and nucleic acids are broken apart for energy or converted to carbohydrates or fats, enzymes remove nitrogen in the form of ammonia (NH₃). Ammonia is very toxic, in part because its ion, ammonium (NH₄⁺), interferes with oxidative phosphorylation. Although some animals excrete ammonia directly, many species expend energy to convert it to a less toxic compound, either urea or uric acid, prior to excretion.
Describe Apical Dominance:
Because of chemical communication by plant hormones, the closer an axillary bud is to an active apical bud, the more inhibited it is.
Describe connective tissues:
Bind and support other tissues
Stomata open during the day in response to:
Blue light triggering the uptake of K+ by guard cells
Describe the function of the Sieve-tube members & Companion cells:
Both of these cells are specialized to conduct sugars throughout the phloem. Sieve-tube members for tubes, while the companion cells load sugars into the sieve-tube members.
Animals obtain the energy they need for growth by:
Breaking down organic molecules
Long distance transport in plants occurs through ________ ______ the movement of liquid in response to a pressure gradient. Describe it:
Bulk flow. Bulk flow always occurs from higher to lower pressure, however, bulk flow is independent of solute pressure.
Describe the female parts of a flower:
Carpels: - Ovary: the portion of a carpel in which the egg containing ovules develop - Ovules: A structure that develops within the ovary of a seed plant and contains the female gametophyte. - Style: The stalk of the flower's carpel, with ovary at base and stigma at the top - Stigma: The sticky part of a flower's carpel, which receives pollen grains.
In addition to a cell phospholipid bilayer, plants also have:
Cell wall (ex: cellulose)
Describe the Casparian strip:
Cells of the endodermis have a band of waterproof, waxy Suberin. The casparian strip completely block the apoplastic route of water and minerals into the xylem. They must follow the symplastic route to enter the xylem. This forces all mineral and water to pass through the membrane of a living cell; this allows selective permeability to filter out unwanted or unnecessary substances from entering the xylem.
Compare derivative and stem cells:
Cells that remain as sources of new cells are called stem cells, which perpetually divide and remain functionally unspecialized. The new cells displaced from the meristem, which are known as derivatives, divide until the cells they produce become specialized in mature tissues. Once displaced from the meristem, derivatives will divide until their daughter cells specialize.
Incomplete vs. Complete Digestive Tracts:
Complete Digestive Tract (alimentary canal)- Rather than a gastrovascular cavity, animals with complex body plans have a digestive tube with two openings: a mouth and an anus. Food moves along the alimentary canal in a single direction, encountering a series of specialized compartments that carry out stepwise digestion and nutrient absorption. An animal with an alimentary canal can ingest food while earlier meals are still being digested, a feat that is likely to be difficult or inefficient for an animal with a gastrovascular cavity. Incomplete Digestive Tract- Animals with relatively simple body plans typically have a digestive compartment with a single opening. This pouch, called a gastrovascular cavity, functions in digestion as well as in the distribution of nutrients throughout the body. EX: Small freshwater cnidarians (hydras). The hydra uses its tentacles to stuff captured prey through its mouth into its gastrovascular cavity. Specialized gland cells secrete digestive enzymes that break the soft tissues of the prey into tiny pieces. Other cells lining the cavity engulf these food particles, and most of the hydrolysis of macromolecules occurs intracellularly. After the hydra has digested its meal, undigested materials that remain in its gastrovascular cavity, such as exoskeletons of small crustaceans, are eliminated through its mouth. Many flatworms also have a gastrovascular cavity.
Legumes (members of the pea family) have roots with swellings called nodules that:
Contain nitrogen fixing bacteria
If a plant is deficient in phosphorous, it will not be able to make:
DNA
A plant's outer protective covering:
Dermal Tissue
The stage of a cardiac cycle in which a heart chamber is relaxed & fills with blood:
Diastole
Describe the structure and function of a nephron:
Each nephron consists of a round renal corpuscle (that resides up in the cortex), followed by a long and winding renal tubule that loops around between the cortex and medulla. The outer layer of the renal corpuscle is the bowman's capsule. Inside the bowman's capsule is a tangle of capillaries called the glomerulus.The endothelium of the glomerulus is very porous, allowing fluid, waste products, ions, glucose, and amino acids, into bowman's capsule. However, larger molecules like blood cells and proteins are blocked from entering the capsule so they remain in the blood and exit through the Vasa Recta. The remaining contents that pass into bowman's capsule is called filtrate. The filtrate then passes along to the three parts of the renal tubule. The long curly shape of the nephron provides more time and space for reabsorption. The first segment is called the proximal convoluted tubule (PCT). The walls of the PCT are made of cuboidal epithelial cells with large mitochondria that use active transport to pull sodium ions from the filtrate. Then the filtrate drops down into the loop of Henle. The loop of henle uses a salt concentration gradient to maximize water absorption. Salt is actively pumped out in the ascending limb (which makes very salty interstitial fluid), therefore in the ascending limb water passively diffuses out (by osmosis) into the interstitial fluid. Then the filtrate is officially urine when it enters the distal convoluted tubule (DCT), which finally empties into the collecting duct.
Organisms that get most of their heat from external sources:
Ectotherms
The innermost layer of the root cortex is the:
Endodermis
The innermost layer of the cortex of a root:
Endodermis, a cylinder one cell thick that forms the boundary with the vascular cylinder. The endodermis is a selective barrier that regulates passage of substances from the soil into the vascular cylinder
Bacteria that lives between cells within the plant itself. They depend on nutrients such as amino acids, sugars, and organic acids secreted by plant cells. Some produce chemicals that stimulate plant growth or antibiotics that protect roots from diseases:
Endophytes
Organisms that are warmed mostly by heat generated by metabolism:
Endotherms
What are the four types of tissues in animals?
Epithelial, muscle, connective, and nervous
Tissue that lines the intestines, secretes digestive juices, and absorbs nutrients:
Epithelium
Describe the pressure potential in the xylem:
Except when there is root pressure, the pressure potential in xylem is always negative. The greater the tension, the more negative the pressure.
What are the two types of sclerenchyma cells?
Fibers & Sclereids
Cells within the connective tissue that secrete collagen:
Fibroblasts
Identify the structures and functions of the parts of flowers:
Flowers are composed of four types of floral organs: carpels, stamens, petals, and sepals. All organs are attached to the receptacle. Carpel contains : ovary, style, and stigma Stamen contains : anther and filament
Explain the relationship between flowers, seeds and fruit:
Flowers are the reproductive shoots of angiosperm sporophytes. They contain the ovules (ovary) and the pollen and male gametophyte (anther). After double fertilization each ovule develops into a seed and the ovary develops into a fruit which encloses the seed and aids in their dispersal through wind and animals. Therefore, flowers are the reproductive site, ovules are the seeds, and the ovary is the fruit.
Describe epithelial tissue:
Forms interactive surfaces on external and internal surfaces. Covers the outside of the body and lines organs & cavities. Functions as a barrier against mechanical injury, pathogens, and fluid loss. Ex. The epithelium lines the intestines and secretes digestive juices and absorbs nutrients.
A plant cell placed in a solution with a higher water potential will:
Gain water & become turgid. Because water moves from a region of higher water potential to a region of lower water potential, a cell in such a solution will gain water and become turgid.
Nervous tissue support cells:
Glia
Describe ground tissue:
Ground tissue contains cells for storage, photosynthesis, support, or short-distance transport. The two types of ground tissue are pith and cortex. The pith is the innermost tissue and the cortex is the outermost tissue.
What regulates the opening and closing of stomata?
Guard cells
Cells of connective tissues tend to:
Have lots of extracellular matrices (spaces in between the living cells)
Plants that exhibit only primary growth are:
Herbaceous plants
Describe how hormones travel in the body:
Hormones are molecules that are transported in the blood. They are secreted from an endocrine cell into the extracellular matrix & travel everywhere in the body through the blood stream. The cells that have receptors for the hormone will respond and the other cells will ignore the hormone.
The remains of dead organisms and other organic matter that acts as a great fertilizer:
Humus
How do some researchers determine which elements are essential?
Hydroponic culture- where plants are grown in mineral solutions instead of water; they simply add the essential elements to the water.
Acts as the thermostat in mammalian regulation of body temperature:
Hypothalamus
Why is soil PH important?
If the soil PH dips to 5 or below, toxic aluminum ions become more soluble and are absorbed by roots, stunting root growth
Compare Open vs. Closed circulatory systems:
In an open circulatory system, the circulatory fluid, called hemolymph, is also the interstitial fluid that bathes body cells. Arthropods, such as grasshoppers, and some mollusks, such as clams, have an open circulatory system. Contraction of the heart pumps the hemolymph through the circulatory vessels into interconnected sinuses, spaces surrounding the organs. There, chemical exchange occurs between the hemolymph and body cells. Relaxation of the heart draws hemolymph back in through pores, which have valves that close when the heart contracts. Body movements periodically squeeze the sinuses, helping circulate the hemolymph. In a closed circulatory system, a circulatory fluid called blood is confined to vessels and is distinct from the interstitial fluid. This type of circulatory system is found in annelids (including earthworms), many mollusks, and all vertebrates. In closed circulatory systems, one or more hearts pump blood into large vessels that branch into smaller ones that infiltrate the tissues and organs. Chemical exchange occurs between the blood and the interstitial fluid, as well as between the interstitial fluid and body cells.
Give a brief overview of the endocrine system:
In communicating between different locations in the body, the endocrine system broadcasts signaling molecules called hormones everywhere via the bloodstream. Only certain cells are responsive to each hormone. Hormone pathways may be regulated by negative feedback, which damps the stimulus, or positive feedback, which amplifies the stimulus and drives the response to completion.
Describe the genetic engineering of plants:
In genetic engineering, genes from unrelated organisms are incorporated into plants. Genetically modified (GM) plants have the potential of increasing the quality & quantity of food worldwide and may also become increasingly important as biofuels. EX: GM crops like golden rice provide more vitamin A and Bt maize, which are insect resistant.
Describe the layers of a tree trunk & explain why trunks thicken with age:
In order from the innermost layers to the outermost layers: The innermost layers are secondary xylem, which is essentially dead wood. The next layer is the vascular cambium, which gives rise to the secondary xylem and phloem. The outer cells become phloem and the inner cells become xylem. The next layer is the secondary phloem, and the final, outermost layer, is the cork which is produced by the cork cambium. The annual growth rings evident in cross sections of most tree trunks in temperate regions result from the yearly activity of vascular cambium.
Describe the cell division of primary growth:
In primary growth, the apical meristems will divide first. Spindle fibers are oriented in a horizontal direction. In division, one cell will remain as a stem cell & the other will continue to divide. Then in primary meristems the cells will grow larger and start to become differentiated.
Describe how plants use carbon to make G3P:
In the Calvin cycle, plants will take CO₂ from the air, and fix it with rubisco to a 5-carbon RUBP, then split that into two three carbon compounds which get converted to G3P. The product of photosynthesis that the plant uses to make its organic molecules.
Link positive feedback & digestion:
In the lumen of the stomach, chief cells aid digestion by secreting pepsinogen. The parietal cells transport Hydrogen ions into the lumen, causing chloride cells to diffuses into the lumen. These ions combine to form hydrochloric acid, which lowers the pH to about 2. This very acidic gastric juice converts a few molecules of pepsinogen to Pepsin. The new pepsin molecules, then convert the remaining pepsinogen cells to pepsin. The cycle of new pepsin molecules continue to convert remaining pepsinogen molecules into pepsin, creating a positive feedback loop.
Contrast the dermal tissue in woody vs. non-woody plants:
In woody plants, the dermal tissue forms a tough periderm (bark). Non-woody plants consist of an epidermis that sometimes contain a cuticle.
What goes in the xylem?
Inorganic minerals & water
What allows damaged leaves to rapidly regrow?
Intercalary meristems account for the ability of lawns to grow following mowing. The ability of grasses to regrow leaves by intercalary meristems enables the plant to recover more effectively from damage incurred from grazing herbivores.
Growth that occurs through a plants entire life:
Interdeterminate Growth
What does a plant need nitrogen for? How do they obtain it?
It is a component of nucleic acids, proteins, and chlorophyll. Plants cannot directly use nitrogen from the air, they use amino acids as a source of nitrogen. For N₂ to be of use in plants, it must be reduced to NH₃ by a process called Nitrogen fixation. All nitrogen fixing organisms are bacteria.
If you place a cell in a hypertonic solution, what will happen?
It will become flaccid because the water will be drawn to the higher concentration of solutes outside of the cell. If this occurs in plant cells, plasmolysis will occur. Plasmolysis is when the cell shrinks and pulls away from the cell wall.
How does branching differ in roots versus stems?
Lateral roots emerge from the pericycle and destroy plant cells as they emerge. In stems, branches arise from axillary buds and do not destroy any cells.
Very young leaf:
Leaf primordia
List the 3 main functions of a leaf:
Leaves carry out gas exchange between the plant & the environment, they are considered the main photosynthetic organ of a plant that, and they also house the vascular tissue that make up the veins in the leaf.
Small raised areas on the periderm of a tree caused by space between cork cells. Enables living cells within a woody stem or root to exchange gases with the outside air.
Lenticels
Gas exchange not only occurs in the stomata, but also in the:
Lenticils
How do plants make G₃P?
Light is the source of energy needed to make sugars from CO₂ & water
The most fertile topsoils are ______, which are composed of roughly equal amounts of sand, silt, and clay. These soils provide ample surface area for the adhesion and retention of minerals and water.
Loams
What is the most fertile top-soil?
Loams- a combination of clay, sand, and silt
Describe how sugars are transported from sources to sinks:
Mature leaves are the main sugar sources, although storage organs can be seasonal sources. Growing organs such as roots, stems, and fruits are the main sugar sinks. Phloem loading depends on the active transport of sucrose. Sucrose is co-transported with H⁺, which diffuses down a gradient generated by proton pumps. The loading of sugar at the source and unloading at the sink maintain a pressure difference that keeps sap flowing through a sieve tube.
Gamete formation involves a type of cell division called:
Meiosis
Describe apical meristems:
Meristems at the tips of roots & shoots; provides cells for primary growth
Cells within the connective tissue that engulf foreign particles and cell debris:
Microphages
What do you call the main vein in Eudicots?
Midrib
Of the essential nutrients required by plants, most are:
Minerals
How might roots react when they encounter a region of the soil that is low in nitrates?
Minimize branching; roots encountering pockets of soil low in nitrates will pass through these pockets rather than branching.
Define Mycorrhizae:
Mutualistic relationships between roots & fungi. The fungus absorbs carbohydrates from the roots. In return, the fungus's mycelium increases the surface area for the uptake of water & minerals by the roots.
Functional unit of the kidney:
Nephron
Tissue that functions in the processing, receipt, and transmission of information:
Nervous Tissue
Specialized cells that are the basic unit of the nervous system:
Neurons
In plants, Nitrogen fixation is performed by:
Nitrogen fixing bacteria that convert atmospheric nitrogen to ammonia, which is then converted to ammonium.
By trapping insects, carnivorous plants obtain __________. Why do they need this?
Nitrogen, to produce proteins
70% of gas in the atmosphere is ________. How do plants utilize this?
Nitrogen. Plants use nitrogen-fixing bacteria to take up nitrogen in the form of nitrate (ammonium) which is a very beneficial nutrient.
What is the difference between the root epidermis and the shoot epidermis?
Only the shoot epidermis produces a waxy cuticle called a cuticle.
The diffusion of free water across a membrane:
Osmosis
List the 3 major organic compounds in plants:
Oxygen, Hydrogen and Carbon
How does oxygenated blood enter the kidney?
Oxygenated blood enters the kidneys through the large renal arteries.
Most of the photosynthesis in plants takes place in what cells?
Parenchyma
Lateral roots in seed plants are initiated by cell divisions in the:
Pericycle
Carbon, oxygen, hydrogen, nitrogen, phosphorous, sulfur, potassium, calcium, and magnesium:
Plant Macronutrients
Describe how plants move sugars down to the roots through translocation:
Plants usually transport sucrose (extra glucose from photosynthesis) down (sometimes up) to the sugar sink which is the organ that is consuming it. The sugar sink usually needs sugar because it is undergoing cellular respiration or growth. The sucrose is transported into the sieve tube elements by facilitated diffusion with a proton gradient. The water from the nearby xylem will be attracted to the high concentration of sugars in the phloem, therefore water will diffuse into the phloem and create pressure that pushes the sugars downward to the roots.
Describe pollination & what occurs after:
Pollination, which precedes fertilization, is the placing of pollen on the stigma of a carpel. After pollination, the pollen tube discharges two sperm into the female gametophyte.
Compare and contrast Primary & Secondary growth:
Primary Growth: 1) Occurs from the Apical Meristem 2) Growth in length ↑↓ 3) Stops after the completion of tissue differentiation 4) Develops the epidermis, cortex, and the primary vascular tissues 5) Occurs in all parts of al plants Secondary Growth: 1) Occurs from the cambium/lateral meristems 2) Growth in diameter ↔ 3) Only occurs after primary growth is finished 4) Only occurs in mature parts 5) Develops the bark, periderm, secondary phloem, and secondary xylem Both: 1) Meristems generate new cells through mitosis (cell division)
Which is closest to the center of a woody stem?
Primary xylem
While animal cells use sodium potassium pumps, plant cells mainly use:
Proton pumps to establish a membrane potential
The living part of the cell that creates turgor pressure:
Protoplast
The only veins that carry oxygenated blood:
Pulmonary veins
Distinguish between animal regulators & conformers:
Regulators control internal variables despite the external environment, while conformers allow internal variables to vary with external changes.
Why does pinching off the top of a plant make it bushier?
Removing the apical meristem stimulates growth in the axillary buds, thus making the plant bushier. Because of apical dominance, axillary buds remain dormant until removal of the apical bud or shading of the apical bud. Once the apical bud is removed, the axillary buds give rise to lateral shoots and make the plant bushier.
Bacteria that lives in the soil surrounding the plants roots. They depend on nutrients such as amino acids, sugars, and organic acids secreted by plant cells. Some produce chemicals that stimulate plant growth or antibiotics that protect roots from diseases. The most efficient metabolism between plants and nitrogen-fixing bacteria occurs in the nodules formed by:
Rhizobacteria
A cross section of a plant part exposes epidermis, a thick cortex, and a central cylinder of xylem and phloem. This part is a:
Root
Extensions of a root's epidermis that increase absorption and surface area:
Root hairs
Describe the function and site of action of several digestive enzymes:
Saliva contains a large amount of the enzyme amylase, which breaks down starch and glycogen. Most chemical digestion occurs not in the mouth but in the small intestine, where amylase is also present. The stomach secretes the components of a digestive fluid called gastric juice. The components of gastric juice are produced by cells in the gastric glands of the stomach. The action of parietal cells and chief cells generates HCL (hydrochloric acid) & pepsin, which together help liquefy food in the stomach. The concentration of HCL is so high that the pH of gastric juice is about 2. This low pH denatures proteins in food, increasing exposure of their peptide bonds. The exposed bonds are then attacked by pepsin—a protease, or protein-digesting enzyme. Unlike most enzymes, pepsin is adapted to work best in a very acidic environment. By breaking peptide bonds, it cleaves proteins into smaller polypeptides and further exposes the contents of ingested tissues.
Heartwood and sapwood consist of:
Secondary Xylem
Give a real world example of a sclereid:
Seed coats (Peach pit)
What are internodes?
Segments on a stem in-between the nodes
What are some of the hormones that affect hunger levels?
Several hormones, including leptin and insulin, regulate appetite by affecting the brain's satiety center.
What are the two types of Phloem:
Sieve-tube members & Companion cells
Discuss the composition, source and action of bile.
Since fats are insoluble in water, they form large globules that cannot be attacked efficiently by digestive enzymes. In humans and other vertebrates, fat digestion is facilitated by bile salts, which act as emulsifiers (detergents) that break apart fat and lipid globules. Bile salts are a major component of bile, a secretion of the liver that is stored and concentrated in the gallbladder. Then after being broken down into smaller particles, an enzyme called pancreatic lipase breaks the fat into free fatty acids & monoglycerides. They are now small enough to pass through the epithelial cell layer of the vili into the lymph capillary.
Single vs. Double Circulation:
Single circulation- A circulatory system consisting of a single pump and circuit, in which blood passes from the sites of gas exchange to the rest of the body before returning to the heart. These animals have a heart that consists of two chambers: an atrium and a ventricle. Double circulation- A circulatory system consisting of separate pulmonary and systemic circuits, in which blood passes through the heart after completing each circuit. In animals with double circulation, the pumps for the two circuits are combined into a single organ, the heart. In one circuit, the right side of the heart pumps oxygen-poor blood to capillary beds in gas exchange tissues, where there is a net movement of O2 into the blood and of CO2 out of the blood. In most vertebrates, including reptiles and mammals, this is called a pulmonary circuit because gas exchange takes place in the lungs.
What are the three types of muscle tissue:
Skeletal, cardiac, and smooth
Vitamins are what type of molecule?
Small organic
Vascular plants are ___________ dominant
Sporophyte; the gametophytes are the sex organs that are less noticeable
Which part of a plant is likely to display mineral deficiency first?
Symptoms will show up first in older organs because young, growing tissues have more "drawing power" for nutrients in short supply.
The stage of a cardiac cycle in which a heart chamber contracts and pumps blood:
Systole
Distinguish the 2 main parts of a leaf:
The Blade is the flattened portion of the leaf body. The Petiole is the small stalk that joins the lead to the stem at a node.
When referring to phloem transport, the "sink" in roots is created by:
The active transport of sugars from phloem to cortex cells
Plants obtain carbon from:
The air
Tell where the hepatic portal vein (system) is and its general roll:
The capillaries and veins that carry nutrient-rich blood away from the villi converge into the hepatic portal vein, a blood vessel that leads directly to the liver. From the liver, blood travels to the heart and then to other tissues and organs. This arrangement serves two major functions. First, it allows the liver to regulate the distribution of nutrients to the rest of the body. Because the liver converts many organic nutrients to different forms for use elsewhere, blood leaving the liver may have a very different nutrient balance than the blood that entered. Second, the arrangement allows the liver to remove toxic substances before they can circulate broadly. The liver is the primary site for detoxifying many organic molecules foreign to the body, including drugs.
What allows stomata to open and close?
The cellulose microfibrils and potassium and water molecules coming into the vacuoles.
Distinguish between atria & ventricles of the heart:
The chambers that receive blood entering the heart are called atria (singular, atrium). The chambers responsible for pumping blood out of the heart are called ventricles
Describe at least three specializations in plant organs and plant cells that are adaptations to life on land:
The cuticle of leaves and stems protects these structures from water loss. Collenchyma and sclerenchyma cells have thick walls that provide support for plants. Strong, branching, multicellular roots help anchor the plant in the soil.
If a plant's leaves are yellowing, it may be that the plant is deficient in:
The elements needed to make chlorophyll, one of which is magnesium
While the nervous system responds very rapidly, ...
The endocrine system responds more slowly.
Give a general overview of the four floral organs:
The four floral organs are sepals, petals, stamens, and carpels. Sepals protect the floral bud. Petals are modified leaves that help attract pollinators. Stamens bear anthers in which haploid microspores develop into pollen grains containing a male gametophyte. Carpels contain ovules (immature seeds) in their swollen bases. Within the ovules, embryo sacs (female gametophytes) develop from megaspores.
Describe how the kidneys and liver work to together to filter out nitrogenous waste from the body:
The kidneys filter waste products of your blood, mainly the waste products like nitrogenous bases made by metabolizing protein. Since we can't store amino acids, extra ones get processed into storable carbs or fats. However, the amine group isn't used in those storage molecules, so it is converted to NH₃ (toxic ammonia). The liver converts the ammonia into urea, which our kidneys filter out into our urine.
Describe absorption in the large intestine:
The large intestine includes the colon, cecum, and rectum. The small intestine connects to the large intestine at a T-shaped junction. One arm of the T is the colon, which leads to the rectum and anus. The other arm is a pouch called the cecum. In animals that eat large amounts of plant material the cecum has an important role in fermenting ingested material. In humans, the cecum has an appendix, a finger-shaped extension, that serves as a reservoir for symbiotic microorganisms. The colon completes the recovery of water that began in the small intestine. What remains are the feces, the wastes of the digestive system, which become increasingly solid as they are moved along the colon by peristalsis. The undigested material in feces includes cellulose fiber. Although fiber provides no caloric value (energy) to humans, it helps move food along the alimentary canal.
What is a leaf's ground tissue?
The mesophyll: Palisade & Spongy. Mesophyll consists mainly of parenchyma cells specialized for photosynthesis.
Define micronutrients in plants:
The micronutrients are: chlorine, iron, manganese, boron, zinc, copper, nickel, and molybdenum. Sodium is a ninth essential micronutrient for plants that use the CAM or C4 pathway of photosynthesis. Micronutrients function in plants mainly as enzyme cofactors.
What are the three layers of the kidney?
The outermost- Renal cortex Renal medulla The innermost- Renal pelvis- surrounded by smooth muscle that uses peristalsis to move urine out of the kidney, into the ureter, and to the bladder.
Describe glucose homeostasis:
The pancreatic hormones insulin and glucagon maintain glucose homeostasis by tightly regulating the synthesis and breakdown of glycogen (Figure 33.19). After a carbohydrate-rich meal, for example, insulin secretion promotes biosynthesis of glycogen from glucose entering the liver in the hepatic portal vein. Between meals, when blood in the hepatic portal vein has a much lower glucose concentration, glucagon stimulates the liver to break down glycogen, convert amino acids and glycerol to glucose, and release glucose into the blood. Together, these opposing effects of insulin and glucagon ensure that blood exiting the liver has a glucose concentration in the normal range at nearly all times.
Describe water potential:
The property of water that makes it diffuse down its concentration gradient. The two main factor that affect it are solute concentration & physical pressure.
Decsribe the seed coat & fruit:
The seed coat encloses the the embryo along with a food supply stocked in either the endosperm or the cotyledons. The fruit protects the enclosed seeds and aids in wind dispersal or in the attraction of seed-dispersing animals.
What is the difference between the palisade mesophyll and the spongy mesophyll of a leaf?
The spongy mesophyll has air spaces, while the palisade mesophyll is made up of more tightly packed, elongated cells.
Describe the male parts of a flower:
The stamen consists of the anther, which produces the pollen, and the filament, which attaches the anther to the base of the flower.
Describe the function of the stomata:
The stomata allow exchange of CO₂ and O₂ between the surrounding air and the photosynthetic cells inside the leaf. In addition to regulating CO₂ uptake for photosynthesis, stomata are major avenues for the evaporative loss of water.
How do sieve-tube members lack a nucleus, ribosomes, a distinct vacuole, and cytoskeleton elements and still remain alive?
Their adjacent companion cells in the phloem have a nucleus and ribosomes that not only serve the companion cells themselves, but also serve the adjacent sieve-tube members.
Collenchyma cells can be recognized by:
Their unevenly thickened cell walls
Mammals and birds maintain their internal temperature through:
Thermoregulation
Why do sieve-tube members lack a nucleus, ribosomes, a distinct vacuole, and cytoskeleton elements?
This lack of cellular contents allows nutrients (sugars) to pass easily in the cell.
Describe how the Xylem can transport water up the plant & against gravity?
Through transpiration, water diffuses from inside a leaf to the outside environment through evaporation through the stomata. In the air spaces inside the spongy mesophyll, water is constantly evaporating off of the surface of surrounding cells. Water forms a film of cell walls (usually cellulose) by adhesion. Because of the hydrogen bonds that allow cohesion and adhesion, transpiration creates a tension that pulls water molecules up the plant.
Describe the 3 main functions of roots:
To anchor vascular plants in the ground, absorb minerals & water from the soil, and store carbohydrates.
What is the main function of a stem?
To bear the leaves & buds of a plant.
Describe the function of a root cap:
To protect the apical meristem as the root pushes through the soil. They secrete a poly lubrication.
What are the two types of Xylem:
Tracheids & Vessel elements
Organisms that have been engineered to express a gene from another species:
Transgenic
List an "atypical" type of root hairs:
Trichomes- hair like outgrowth of the shoot epidermis, usually found in desert species.
Explain what is meant by double fertilization and what results from it:
Two sperm are needed for double fertilization, a process in which one sperm fertilizes the egg, forming a zygote & eventually an embryo, while the other sperm combines with the polar nuclei, giving rise to the food-storing endosperm.
Describe the function of Phloem:
Vascular tissue that transports sugars and other products of photosynthesis down to the roots for storage or to sites of new growth. ↓
Describe the function of Xylem:
Vascular tissue that transports water and dissolved minerals from the roots up the the shoot. ↑
If you place a cell in a hypotonic solution, what will happen?
Water will rush into the cell because there are more solutes inside the cell. Plant cells naturally remain in this turgid state.
Describe the transport of water & minerals from root hairs to the xylem:
When water reaches a root hair, it is drawn into the hydrophilic structure of the cell wall. Then the water is transported across the plasma membrane of the epidermis/cortex. Once in the cells cytoplasm, the water and minerals can move from cell→cell through plasmodesmata; taking the symplastic route into the vascular cylinder. Due to the casparian strip, all minerals and water must eventually join the symplastic route to enter the xylem.
What are nodes?
Where the leaves are attached on a stem.
Describe absorption in the small intestine:
With digestion largely complete, the contents of the duodenum move by peristalsis to the jejunum and ileum, the remaining regions of the small intestine. There, nutrient absorption occurs across the lining of the intestine. Large folds in the lining are studded with finger-shaped projections called villi. Within the villi, each epithelial cell has many microscopic projections, or microvilli, that face the opening. Together, the folds, villi, and microvilli of the small intestine have an enormous surface area that is evolutionary adaptation that greatly increases the rate of nutrient absorption. Water-soluble nutrients, such as amino acids and sugars, enter the bloodstream, whereas fats are transported to the lymphatic system.
What advantages did plants gain from the evolution of secondary growth?
With the evolution of secondary growth, plants were able to grow taller and shade competitors.
Plants that are adapted to arid environments:
Xerophytes
What are the two types of vascular tissue in plants:
Xylem & phloem
