Biology Exam 2
What is karotype?
-A picture of all an organism's chromosomes arranged by size -Can be used to detect chromosomal abnormalities. For instance: Sometimes an individual will have an extra chromosome or be lacking a chromosome
Tell me about Telophase
-Chromosomes begin to unwind -New nuclear membranes are created
What does haploid and diploid mean?
-Haploid means "half"; one of each chromosome The haploid number in humans is 23 chromosomes - Diploid means "two"; two of each chromosome The Diploid number in humans is 46 chromosomes
Tell me about Prophase
-Nuclear membrane disintegrates -Chromosomes thicken -Spindle fibers attached to chromosomes
Tell me about Asexual reproduction
-One parent -New cells will be genetically identical to parent cell, no genetic variation -Good because you can produce lots of offspring very quickly -Bad because there is no genetic diversity leaving the population susceptible to disease, etc... -Types of asexual reproduction: Binary fission (bacteria), Budding, Fragmentation
Tell me about adaption
-Species become better suited to their environment -Never a complete process because the environment always changes and environmental change is much more rapid process than natural selection and adaptation
What happens during Cytokinesis?
-The cell divides creating two new daughter cells -Daughter cells will be exact copies of the original cells -The cell membrane pinches in during cytokinesis in animal cells -A new cell wall forms in plant cells splitting the original cell in two
Tell me about Amino Acids
-The subunits that make a protein -All organisms use the same 20 amino acids to make their proteins -The difference is in the "R" group; there are 20 different "R" groups; some big, some small, some polar, some nonpolar, etc...
What are Check Points?
-Three Checkpoints which are used to make sure the cell is ready to divide, if there is a problem it will be discovered at these checkpoints and cell division will be aborted -G1 Checkpoint - Is the cell big enough to divide? -G2 Checkpoint - Was the DNA copied correctly? -M Checkpoint - Did the cell divide correctly? Did each daughter cell receive the correct amount of chromosomes?
Tell me about Sexual reproduction
-Two parents; each donate a half set of genetic information -New cells will be genetically different from parent cells -Good because it creates genetic diversity -Bad because it takes two individuals, and is time and energy consuming -Sources of genetic variation: *Crossing over → *Independent assortment Homologous chromosomes can line up in different ways during be metaphase I *Random Fertilization Which sperm cell will fertilize the egg is in some respects a random process
What is Cell Theory?
1. All living things are made up of cells 2. Cells come from preexisting cells 3. Cells are the basic unit of life
How many pairs of sex chromosomes do humans have?
2 (Male sex chromosomes are XX, Female's are XY)
Photsynthesis Reaction
6CO2 + 6H20 - CH12O6 + 602
What happens after cytokinesis in meiosis?
A second round of cell division occurs. Prophase II - Telophase II (are very similar to the events in mitosis)
Two types of respiration
Aerobic and Anaerobic (Fermentation)
What happens in Prophase 1
Homologous chromosomes find each other and exchange pieces; this is one source of genetic variation (shuffling of the genetic deck)
What happens in Metaphase 1
Homologous chromosomes line-up next to each other forming 2 lines in the middle of the cell (which line you get in is random, this is independent assortment another source of genetic variation
What happens in Anaphase 1
Homologous chromosomes move to opposite ends of the cell (they do not split into like in mitosis anaphase)
Properties of H20
Ice floats (the solid is less dense than the liquid) Very unusual Can be in all three phases on Earth Adhesion - Water molecules stick to other things (meniscus) Cohesion - Water molecules stick to one another High Specific heat - It takes a lot of energy to raise the temperature of water
What is a habitat?
Place where an organism or a biological population normally lives or occurs.
Biological Interactions in an Ecosystem
Predation - One species feeds off another species Competition - When two species share requirement for limited resources and reduces the fitness of one or both of the species; no two species can occupy the same niche, the one better adapted will outcompete the other Parasitism - One organism benefits, the other has its fitness reduced; similar to predation but usually the host is not killed immediately Mutualism - Relationship in which both organisms benefit Commensalism - Relationship in which one organism benefits the other is relatively unaffected.
What are the phases of Meiosis?
Prophase I Metaphase I Anaphase I Telophase I/cytokinesis Prophase II - Telophase II
Vacuole traits:
Storage compartment Plant cells have a large central vacuole Animal cells have several small vacuoles
Нуpothesis
Testable, well-researched explanation for a physical phenomenon
What happens in Telophase 1
The cell undergoes cytokinesis
Tell me about Anaphase
The chromosomes splits in two (sister chromatids) and each half begins to migrate to one side of the cell (through the aid of the spindle fibers)
Primary succession-
colonization of barren land by lichen a pioneer organism
Define heterozygous
contain differing gene version
Define homozygous?
contains 2 copies of the same gene version (differing version of the same gene are called ALLELES)
What are Analogous Structures?
different ways to make the same type of structure (ex. Wings) which serves the same function.
What are the two types of RNA?
mRNA tRNA
Tell me about succession
the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax community is established
What is the end result of meiosis?
the production of 4 gametes (daughter cells) each containing only half the normal number of chromosomes (they are haploid)
Who was Mendel?
"Father of Genetics" experimented on pea plants
Traits of Mitochondria:
"Power plant" Produces energy (aerobic respiration)
Define P generation
"parental" what you start with
Tell me about what a Niche is
(how an organism fits into its environment, its function in the community, the job it performs) For example: Space Utilization Food Consumption Reproductive Habits
Tell me about mRNA
(messenger RNA) o made from DNA in the nucleus o leaves the nucleus carrying the information to the ribosomes o mRNA is read in 3 nucleotide chunks known as codons
Describe Aerobic respiration
*Glycolysis (To break a sugar) o In the cytoplasm o One glucose molecule is broken into two molecules of pyruvate o During the process a net of 2 ATP are formed, NADH is also formed -NADH is a high energy electron carrier, these electrons will be transferred to the mitochondria where the energy can be used to make more ATP *Krebs Cycle -Located in the mitochondria -Pyruvate is converted to CO2, ATP (only a little bit), NADH, and FADH2 *Electron Transport Chain -NADH and FADH2 donate electrons to an "electron transport chain" in the membrane. As the electrons are passed along the chain, protons are pumped across the membrane creating a proton gradient -Oz is the final electron acceptor in the chain; once it has accepted electrons it will grab protons to form water -The protons will be allowed to move down their gradient but only through the -The vast majority of ATP is formed this way (about 34 of the possible 38 ATPS ehzyme ATP synthase, as they pass through the enzyme ATP is formed formed from one glucose molecule)
Describe Active Transport
*Movement of particles against their concentration gradient (from where there are few of them to where there are many of them) *Requires energy (usually in the form of ATP) *Utilizes protein "pumps" Example, the sodium-potassium pump
What is Passive Transport?
*The movement of particles down a concentration gradient (from where are more of them to where there are less of them) ShEimam *Does not require energy *Examples: -Diffusion -Facilitated Diffusion - diffusion which utilizes a transport protein -Osmosis - diffusion of water across a semi-permeable membrane Hypertonic - more dissolved stuff, less water Hypotonic - less dissolved stuff, more water Isotonic - equal
What is a niche?
An ecological niche is the role and position a species has in its environment; how it meets its needs for food and shelter, how it survives, and how it reproduces.
Lysosome
Breaks down worn out cell components or foreign material Contains dangerous chemicals to do the job
Why are cells small?
Cells can't get too big because in larger cells it would take too long to exchange material with the outside environment (i.e. it would take too long to get important things inside and out of the cell) This is due to the surface area to volume ratio, Big cells ratio is too small because volume increases much more rapidly than surface area
Tell me about Metaphase
Chromosomes line up single-file along the middle of the cell
What are autosomes and how many pairs of autosomes do humans have?
Chromosomes that contain genes for characteristics not directly related to the sex of the organism. Humans have 22.
Commensalism
Commensalism relationship in which ONE species BENEFITS and the other is NEITHER HARMED nor BENEFITED
Tell me about Ribosomes
Consists of two halves which form a "sandwich" with the mRNA in the middle
Traits of a nucleus:
Contains the DNA (genes, chromosomes) Directs the activity of the cell Inside we can find a nucleolus, the place where ribosomes are put together
Tell me about Pedigree
Family tree diagram used to track the inheritance of traits (especially diseases through generations). The information in a pedigree can determine whether a trait (disease) is inherited via Autosomal Dominant, Autosomal Recessive, Sex-linked Dominant, Sex-linked Recessive
Endoplasmic reticulum
Flattened membrane sheets connected to the nuclear membrane Two types: Smooth • Makes membranes (phospholipids) Breaks down harmful chemicals "Detoxifier" Rough
Tell me about the "life cycle" of a cell
G1 Phase - -Largest segment of the cell cycle -Cell grows rapidly and carries out its normal functions S Phase - -Cell copies its DNA creating 2 complete sets G2 Phase - -Cell continues to grow -Organelles are duplicated -Microtubules begin to assemble in preparation of cell division. These three phases (G1, S, G2) combined are sometimes referred to as Interphase
Types of variables?
Independent - The variable you have control over, the one you change; graphed on the X-axis (a good experiment only has one independent variable) Dependent - the variable you measure; graphed on the Y-axis Controlled - all other variable, should be the same in all trials The dependent is dependent on what you do to the independent variable
Types of Chemical Bonds
Ionic Covalent Hydrogen
Describe Proteins
Long chains of amino acids Some serve as enzymes Used for locomotion (muscles) Used for structural purposes
Tell me about chromosomes
Made of a long strand of DNA and proteins -The proteins help package the DNA; the DNA winds around the proteins so that it is neat and orderly and doesn't get tied into knots -The DNA stores genetic information (the recipe to make a protein)
Cell Membrane
Made up of a phospholipid bilayer The bilayer is like a sandwich, the outer portions are polar and the middle portion is nonpolar. Small nonpolar things can freely pass through the membrane Charged particles (ions) cannot cross the membrane Embedded in the membrane are proteins of which there are 3 types 1. Marker protein, the "ID tags" of the cell 2. Transport protein, allows certain things in and out of the cell 3. Receptor protein, it passes signals from outside to inside the cell
Describe Lipids
Made up of fatty acid and glycerol Can be saturated or unsaturated (saturated means has as many hydrogen atoms as it can hold). Unsaturated contains double bonds limiting the # of hydrogen atoms. Saturated are straight, unsaturated are bent Include fats, steroids, oils, Energy storage (longer term storage) fats Phospholipids make up the cell membrane Cholesterol makes the lipid bilayer fluid.
Describe Carbohydrates
Made up of sugars (saccharides: mono-, di-, poly-) The ratio of elements is; 1:2:1 ——-> C:H:O Used for energy (C-H bond) ex. starch Used for structure ex. cellulose
Golgi Apparatus
Modifies proteins that were made in the rough ER Adds things to it, such as small sugars (glycoprotein)
Nitrogen cycle,
Nitrogen cycle, the producers take in nitrogen compounds in the soil and pass it from consumers back to producers.
Types of organelles
Nucleus Mitochondria Ribosome Endoplasmic reticulum Vacuole Lysosome Golgi Apparatus Chloroplast Cell membrane
What is evolution?
Over time the beneficial traits will build up in the population; a change in the genetic makeup of a population over time is evolution
What are the three generations?
P generation Fi generation F2 generation
What is Hydrogen Bonding
Results when the + part of one polar molecule is attracted to the- part of a second polar molecule. These are weak + to - attractions
What are Homologous Structures?
Same parts different function (common ancestry; divergent evolution)
Tell me about Meiosis
Series of steps in which a cell undergoes 2 rounds of division producing 4 haploid cells. These haploid cells are called gametes (sex cells) Male gamete is the sperm • Female gamete is the egg or ovum.
What is Covalent Bonding?
Sharing of electrons between 2 atoms sharing is equal → nonpolar covalent bonds sharing is unequal ->polar covalent bond
What is a Punnett square?
Simple way to determine the probability of a cross; can bebused for both phenotypic and genotypic probabilities.
Chloroplast
Site of photosynthesis
Prokaryotic cell traits
Small Bacteria cells Simple • Few organelles They do have ribosomes They lack all membrane bound organelles
Define genotype
The genetic makeup of the organism (what genes does it
Define phenotype
The physical appearance of organism (what it looks like)
What are the purposes of a Control?
Used for comparison, we will compare the results in the experimental trials to this trial to see if there is a change/difference. If there is a difference we can say it is due to the independent variable A good experiment should be repeatable and should be reproducible by others.
What is a Test Cross?
Used to determine the genotype of an individual with the dominant phenotype Cross the individual with dominant phenotype but unknown genotype with an individual who is homozygous recessive. If we get all dominant then unknown was homozygous dominant m. If we get half and half then unknown was heterozygous.
What are three features of Natural Selection?
Variation: There is variation in a trait between and within populations. Heredity: The variation probably has a genetic basis. Differential reproduction: The variants of the trait have different probabilities of surviving to reproduction. Sexual selection is a special type of natural selection acting on an individual's ability to attract a mate and to reproduce
All of water's properties are due to:
Water's small size Water's polar bonds
What is the difference between exponential and logistic growth.
When resources are unlimited, populations exhibit exponential growth, resulting in a J- shaped curve. When resources are limited, populations exhibit logistic growth.
Ribosome
Where proteins are assembled Can either be found "free" in the cytoplasm or attached to the E.R. ("rough" endoplasmic reticulum) "free" ribosomes make proteins that will be used inside the cell Ribosomes on the rough ER make proteins that are either embedded in a membrane or transported outside the cell
What is fermentation?
Without oxygen we cannot use the Krebs cycle or the ETC so a cell can only use glycolysis. We call this fermentation.
Describe the three different types of dispersion.
a. Clumped dispersion - individuals are clustered together. b. Uniform dispersion - individuals are evenly spaced. с. Random dispersion - individuals are randomly arranged.
Differentiate between the three types of survivorship curves. Give an example of each type.
a. Type I - characterized by high age-specific survival probability in early and middle life, followed by a rapid decline in survival in later life. They are typical of species that produce few offspring but care for them well, including humans and many other large mammals. b. Type II - shows a roughly constant mortality rate for the species through its entire life. This means that the individual's chance of dying is independent of their age. c. Type III - depict individuals that mostly die in the early stages of their life. Lots of offspring.
Symbiosis
an association between one or more organisms of different species
Nitrogen-Fixing Bacteria do what?
break down nitrogen compounds and release nitrogen gas to the air or put usable nitrogen in the soil
What are density-dependent factors that limit populations?
factors whose effects on the size or growth of the population vary with the population density. There are many types of density dependent limiting factors such as; availability of food, predation, disease, and migration. However the main factor is the availability of food.
What is Ionic bonding?
o Attraction between oppositely charged particles (ions) - (+ <———> - attraction)
Eukaryotic Cell traits
o Bigger o More complex - Contain many organelles Animal cells, plant cells, etc...
Two names for the movement of LARGE particles in and out of the cell
o Exocytosis - out of the cell o Endocytosis - into the cell
What are the phases of Mitosis?
o Prophase o Metaphase o Anaphase o Telophase
Tell me about tRNA
o brings correct amino acid to ribosome o contains 3 nucleotide chunks known as anticodons o anticodons bind with codons
Define F2 generation
offspring of the F1 generation
Define F1 generation
offspring of the P generation (first familial)
Hydrologic cycle
recycles H2O through evaporation, condensation, precipitation, runoff, groundwater, aquifers, respiration, transpiration, excretion and decomposition
Carbon cycle
recycles carbon through respiration, photosynthesis, fuel combustion, decomposition
Mutualism
relationship in which BOTH species BENEFITS
Parasitism
relationship in which ONE organism BENEFITS at the other's expense
Secondary succession-
sequence of changes that take place after a community is disrupted by natural disaster or human actions.
