Cardiovascular System
What is the pacemaker?
Sinoatrial node
Group of cells that control heartbeat
What is the Cell Theory?
1. All living things are composed of cells
2. The cell is the smallest unit of life
3. Cells come from pre-existing cellsDefine an enzyme. Name factors that affect enzyme activity.
Enzymes are proteins that speed up chemical reactions.
Factors:
Temperature: High temperatures cause loss of shape and denaturation of enzymes. Low temperatures provide little to no energy for enzymatic activity.
pH: Affects charge of enzymes and causes loss of shape.
Substrate Concentration: Substrates cause an increase in enzymatic activity until a certain point where enzymatic activity will not increase no matter how many more substrates are added.
Define the alimentary canal and accessory organs.
Alimentary Canal- organs which food passes (esophagus, stomach, small and large intestine).
Accessory Organs- aid in digestion but do not transfer food (salivary glands, pancreas, liver, gallbladder).
Name 3 causes of natural selection
1. Competition
2. Selection- Environmental pressures
3. Adaptions- Species with beneficial traits survive
4. Evolution- Change in allele frequency
5. Inherited Variation- Genetic variation that can be inherited
Why is there a 12-second delay between the sinoatrial signal to the atrioventricular node?
AV nodes smaller, fewer sodium channels
To make sure the right atrium is thoroughly emptied before the ventricle contracts.
Structure of phospholipids
Hydrophilic heads- polar
Hydrophobic tails- non-polar
Phospholipids self-organize to make heads face exterior environment and tails face interior part of the membrane.
Differentiate DNA and RNA
DNA
-Bases: Adenine, Thymine, Guanine, Cytosine
-Double-Stranded
-Sugar: Deoxyribose
RNA
-Bases: Adenine, Uracil, Guanine, Cytosine
-Single-Stranded
-Sugar: Ribose
Define:
Species
Populations
Communities
Ecosystems
Species: A group of organisms that can produce fertile offspring
Populations: Group of species
Communities: Group of populations
Ecosystem: A community and its abiotic environment
Name and define the three domains of life
1. Eukarya- eukaryotic organisms with a membrane-bound nucleus
2. Archaea- prokaryotic cells that consist of extremophiles (microorganisms that live in extreme conditions)
3. Eubacteria- prokaryotic cells that consist of common pathogenic (disease-causing) forms
Define capillaries
Blood vessels (carry blood) that get rid of the carbon dioxide in the body and allow cells to intake oxygen and glucose (sugar).
Differentiate Prokaryotic and Eukaryotic Cells
Prokaryotic:
DNA naked and circular
No nucleus, no membrane-bound organelles, 70S ribosomes
Reproduction via binary fission
Small
Eukaryotic
DNA linear and bound to protein
Nucleus, membrane-bound organelles, 80S ribosomes
Reproduction via Mitosis and Meiosis
Large
What is PCR? Steps?
Amplifies small quantities of DNA.
Steps:
1. Denaturation: Heat to separate DNA strand
2. Annealing: Primers pick which sequence to copy
3. Elongation: Large quantities of DNA produced
Example of Food Chain
Producer: Carrot Plant
Primary Consumer: Cottontail Rabbit
Secondary Consumer: Feral Cat
Tertiary Consumer: Red Fox
Differentiate and provide examples of analogous and homologous pressures.
Homologous structures
1. Due to common ancestry
2. From divergent evolution (species with similar ancestors diverge)
Example: Pentadactyl limbs in vertebrates
Analogous structures
1. Due to selection pressures
2. From convergent evolution (similar traits in species with different lineage)
Example: Wings of insects, birds, and bats
Differentiate between veins and arteries
Arteries- Sends blood from the heart, Narrow lumen, High pressure, Thick walls, No valves, Large amounts of muscle and elastic fibers
Veins- Sends blood to heart, Wide lumen, Low pressure, Thin walls, Has valves, Small amounts of muscle and elastic fibers
Evidence that Endosymbiosis Theory
Double membrane
Similar modes of replication
Same structure of DNA
70S ribosomes
Describe Transcription
Transcription:
- Process by which mRNA is produced from DNA sequence
-mRNA is complementary to DNA sequence
-DNA Adenine pairs with RNA Uracil
-DNA Thymine pairs with RNA Adenine
-DNA Guanine pairs with RNA Cytosine and vice versa
Pros and Cons of GMOs
Benefits
-Nutritional value of food can be improved
-Crops can lack allergens and have longer lives
-Improve food supply
Disadvantages
-Could cause unknown health effects
-Could cause superweeds
-Limits biodiversity
Give 1 example of the following animal phyla:
1. Porifera
2. Cnidaria
3. Platyhelmintha
4. Mollusca
5. Arthropoda
6. Chordata
1. Sea sponge
2. Jellyfish, coral, sea anemone
3. Tapeworm, planaria
4. Snail, octopus, squid
5. Insects, spiders
6. Mammals, birds, reptiles, amphibians, fish
Describe blood flow
Blood enters through the interior and exterior Vena Cava into the right atrium. Sinoatrial nodes signal heartbeat, so the atria contracts via systole. Through the open tricuspid valve, blood travels from the right atrium to the right ventricle. To prevent backward blood flow, the tricuspid valve closes when the ventricle is full. Right ventricle contracts and blood goes through the pulmonary valve and then, through the pulmonary artery to the lungs where it is oxygenated. The pulmonary valves close when the ventricle is emptied of blood. This process is called pulmonary circulation.
The oxygenated blood enters through the pulmonary vein to the left atrium which contracts, causing blood to go to the left ventricle through the Bicuspid valve. When all of the blood goes to the ventricle, the Bicuspid valve closes to prevent blood from going back to the left atrium. When the ventricle contracts the blood goes through the aortic valve and through the aorta where the blood is released to the organs. This is called systematic circulation.
Describe steps of Interphase and Mitosis
Interphase:
1. G1: Cell grows and prepares for DNA replication.
2. Synthesis: DNA replication.
3. G2: Cell grows and prepares for division.
Mitosis:
1: Prophase: DNA supercoils into chromosomes, Spindle fibers form, Nuclear Membrane dissolves.
2: Metaphase: Spindle fibers cause chromosomes to align in the center.
3: Anaphase: Spindle fibers cause sister chromatids to be pulled to opposite poles.
4: Telophase: Nuclear membrane forms around each set of chromosome set. Spindle fibers disappear and chromosomes decondense.
Define Translation
Process in which proteins are synthesized from mRNA sequence.
tRNA and mRNA are complimentary. mRNA is read in codons. tRNA has anticodons.
tRNA contains specific amino acids.
Ribosomes use amino acid sequence to make proteins.
Describe three main vessels in the liver
Hepatic artery- Receives oxygenated blood
Portal vein- Receives nutrient-rich blood from the gut
Hepatic vein- Contains deoxygenated blood transported from the liver
Name and list characteristics and examples of 4 plant phyla
Bryophyta- no leaves, roots, or stems; no vascularisation, spores, anchored by rhizoids. Example: mosses
Filicenophyta- Leaves, roots, and stems; vascularization, spores, leaves are pinnate. Example: ferns
Coniferophyta- Leaves, roots, and stems; vascularization, seeds in cones, woody stems. Example: conifers
Angiospermophyta- Leaves, roots, and stems; vascularization, seeds in fruits, have flowers and fruits. Example: flowers