IB 104 Exam 1

The best way to describe a hypothesis is:

an explanation, based on observations and assumptions, that leads to a testable prediction.

An experiment is:

a scientific test that is carried out under controlled conditions

A control group in an experiment is necessary to:

allow comparisons to the experimental group and draw conclusions

An independent variable is the factor that is _____ by the researcher and is plotted on the ____ axis of a graph.

manipulated, x

Coat color in mice may be linked to their habitat and visually hunting predators. How has this evolved?

A random mutation causes variation in color. Visual predators cause selection pressure in favor of camouflaged mice.

The dependent variable is the factor that is ____ by the researcher and is plotted on the ____ axis of the graph.

measured, y

A _____ reaction produces polymers, a ____ reaction breaks them down

dehydration, hydrolysis

A polysaccharide is made up of _____ linked by ____ bonds

monosaccharides, glycosidic

The polysaccharide glycogen is used for energy storage in animal cells. It is particularly well suited for this function because it ...

is highly branched with many 'ends' that can be hydrolysed to release glucose quickly for respiration

Phospholipids are excellent building blocks for membranes because they ...

have hydrophobic and hydrophilic properties arranging themselves into a bilayer that can separate the inside of the cell from the outside

Amino Acids consist of...

An alpha carbon, a hydrogen, an amino group, a carboxyl group, and an R group

Proteins are ________ made up of ______________ linked by _________ bonds

polypeptides, amino acids, peptide

Anabolic reactions are _________ and _________ energy, catabolic reactions are ________ and ________ energy.

endergonic, require, exergonic, release

ATP is made up of _________, _________ and _________

adenine, ribose, triosephospate

The function of ATP is best described as follows....

it releases energy when a phophate group is hydrolysed as the product ADP has less free energy

What is the primary structure of a protein?

the sequence or order of amino acids

What is the tertiary structure of a protein and what forces support it? What does tertiary structure determine?

The tertiary structure is the 3D shape due to bonds between R groups. The bonds are ionic, H, hydrophobic interactions and disulfide bridges. The tertiary structure determines the function.

What is the relationship between DNA and proteins?

DNA contains the code that ensures the sequence of amino acids is correct in a protein. DNA therefore ensures that correctly functioning proteins are produced.

What molecules are involved in regulating membrane fluidity?

unsaturated/saturated fatty acids, cholesterol

Hydrophilic molecules can cross the membrane via ___________.

channel and carrier proteins

The function of glycoproteins in membranes is....

Cell recognition

The difference between channel and carrier proteins is .....

Channel proteins have a hydrophilic channel that certain molecules or ions can use as a tunnel, carrier proteins need to change shape to allow substances across membranes

A good definition for diffusion is.....

Diffusion is the net movement of molecules from a region of higher concentration to a region of lower concentration down the concentration gradient, with no ATP needed.

Light microscopes have a _______ resolution than electron microscopes. An advantage is that you can observe _______________.

lower, live specimen

As objects become larger their SA:V gets _________. This means the diffusion path becomes relatively ___________ despite an increased ____________ for absorption.

smaller, longer, surface area

The function of the nucleolus is............

to manufacture ribosomes

Proteins made by the RER move to the _______ to be modified. They then travel in _____ to the plasma membrane and leave by ________.

golgi apparatus, vesicles, exocytosis

Muscle cells have more mitochondria as they require more _______ from _________.

ATP, respiration

The cytoskeleton is made up of three types of molecules...

Microtubules, microfilaments, intermediate filaments

Reduction happens when a molecule...

gains electrons

The two phases of glycolysis are:

energy investment and energy pay-off

The difference between substrate-level and oxidative phosphorylation is .......

the first transfers P directly from a substrate to ADP using an enzyme, the second produces ATP via redox reactions of the ETC (electron transport chain)

Oxidation of pyruvate takes place in the_________ and produces _________ and ___________.

mitochondrial matrix, CO2, AcetylCoA

The first reaction of the citric acid cycle involves........

AcetylCoA reacting with oxaloacetate to form citrate

In Chemiosmosis ____________ diffuse across the mitochondrial membrane via __________.

protons, ATPase

Large animals have a _____ SA:V and therefore the rate of diffusion is ____ to supply all cells with oxygen from the outside environment without specialized ________ systems.

small, not sufficent, gas exchange

Insects need trachea because...

They have a cuticle impermeable to oxygen

Mammalian lungs have a ________ surface are due to many _________. The diffusion path for oxygen is ________ as alveoli are only ___ cell thick. The partial pressure gradient is maintained by ____________ and the _____________ system.

large, alveoli, short, 1, ventilation, circulatory

High carbon dioxide concentration in the blood ________ the pH leading to the ________________ signaling the diaphragm to increase __________.

lowers, medulla oblongata, ventilation

The Bohr effect is due to a ________ pH where cells are respiring, causing the oxygen dissociation curve of hemoglobin to shift to the _______, facilitating ___________ of oxygen.

lower, right, unloading

Animals living at high altitude have hemoglobin dissociation shifted to the _______ to facilitate ____________ of oxgen in a _________ oxygen environment, whilst very active animals have hemoglobin shifted to the __________ to facilitate _____________ of oxygen to respiring cells.

left, loading, low, right, unloading

Grasshoppers have an open circulatory system, the liquid transporting oxygen is called ___________.

hemolymph

One difference between the circulatory system of amphibians and mammals is ............

a three-chambered heart

What sequence describes the correct order through a mammalian circulatory system?

left ventricle, aorta, capillaries, respiring cells, capillaries, vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium

During ventricular ___________ ventricles ____________ and blood is pushed into the _________ and __________ artery via the ______________ valves.

systole, contract, aorta, pulmonary artery, semilunar

The _______ node is called the pacemaker which initiates contraction of ____________ walls during atrial systole of the cardiac cycle. It also sends a signal to the ______ node, which initiates contraction of the ___________.

sinoatrial, atrial, atrioventricular, ventricles

Tissue fluid forms because although the difference in _________ pressure between the inside of the capillary and the outside remains constant along the capillary, the difference in _________ pressure is ___________ at the arteriole end so fluid is pushed out of the capillary.

osmotic, hydrostatic, higher

What are the four nutrients that are essential in a diet?

amino acids, fatty acids, minerals, vitamins

The four feeding mechanisms of animals are ......

filter, substrate, fluid, bulk

Simple animals have _______________ , whereas complex animals have _____________

gastrovascular cavities, alimentary canals

The four accessory glands of the human digestive system are ..........

salivary glands, pancreas, liver, gallbladder

Gastric juices aid digestion by......

lowering the pH, which helps to activate proteases

Carbohydrates are broken down in the _______ and the __________.

oral cavity, small intestine

In DNA replication, the lagging strand is assembled _____ from the replication fork resulting in ___________

away, Okazaki fragments

A DNA nucleotide consists of a ________, a __________, and a ____________

phosphate group, deoxyribose sugar, nitrogenous base

Meselson and Stahl demonstrated ________________ replication of DNA by using different N isotopes. After two replications the double helix of DNA consisted of ___________ density and ___________ density isotopes. No double helix consisted of just the ________ isotope.

semiconservative, low, intermediate, heavy

DNA replication produces a ____________ strand, which initially consists of _____________ fragments, and a ___________ strand.

lagging, Okazaki, leading

In DNA replication, first the enzyme ____________ unzips the double strand by breaking the ________ bonds. The enzyme ______________ adds DNA nucleotides one at the time to the 3' end of the previous nucleotide forming _____________ bonds.

DNA helicase, H, DNA polymerase III, phosphodiester

To start production of the new strand a _________ primer must bind first, which is removed by the enzyme __________.

RNA, DNA polymerase I

The genetic code is a ________ code. It is __________, _______________ and ______________.

triplet, universal, non-overlapping, degenerate

During transcription, the genetic code in the form of DNA triplets is transcribed to _______ by the enzyme __________________. Triplets on the new strand are called ________.

mRNA, RNA polymerase, codon

Translation involves __________ molecules that a carry specific ___________ to a ________________ for polypeptide synthesis. Three bases on these molecules are called _________.

tRNA, amino acid, ribosome, anticodon

There are 3 types of point mutations. These are ________, __________ and ____________. Another type of mutation is addition or deletion which causes a _____________.

silent, missense, nonsense, frameshift

Mutations can be accelerated by exposure to ___________, ___________ or __________.

radiation, chemicals, infectious agents

After two sister ______ have separated into new cells they become _______

chromatids, chromosomes

DNA replication takes place in the ______ phase of interphase

S

During prometaphase, the _________ dissolves

nuclear envelope

During anaphase, _______ apart and become ________ that are pulled to opposite poles of the cell

chromatids, chromosomes

When MPF concentrations are high, cells pass from the _____ to the _____ phase

G2, M