Exam 2 Flashcards
Water behind a dam bridge has a certain amount of stored energy that can be released as the water falls over the top of the dam. It may be enough energy to turn a mill wheel or an electricity-generating turbine. Choose the term that best describes the type of energy stored in the water at the top of the dam.
Potential
What is the definition of energy?
The capacity to do work
Energy is conserved. This means that in any system, _______
total energy input equals total energy output
Kinetic energy is energy in motion. Potential energy is _____ energy
Stored
What is the highest in chemical energy?
one molecule of glucose
In cellular respiration, most energy is released and transferred to ATP when _________
high-energy electrons “fall” to lower energy levels
Identify the principal role of cellular respiration.
To convert the chemical energy of sugars into the chemical energy that fuels life’s processes.
Identify the principal role of photosynthesis
To convert solar energy into the chemical energy of sugars.
Select the ultimate source of energy for nearly every organism on this planet
The sun
Which processes can be carried out by consumers?
Only cellular respiration
The chemical reactions of photosynthesis occur in which cellular organelle?
Chloroplasts
Choose the best explanation as to why both consumers and producers perform cellular respiration
Although they may obtain their sugars in different ways, both consumers and producers rely on cellular respiration to make ATP
How does water enter a plant?
Through the roots
Why do some leaves change color (red, yellow, orange, etc) in the fall?
The chlorophyll molecule breaks down and other pigments now become visible
Imagine a plant with carotenoids but no chlorophyll. Which colors of light would be most beneficial to the plant?
violet-blue
The thick fluids inside the chloroplast is where many of the reactions of photosynthesis take place. This fluid is called _____
Stroma
One of the single pancake-like discs in a chloroplast is called a _____
thylakoid
One of the “stacks of pancakes” is called a ______
granum
The gases needed as inputs for photosynthesis enter the plant through small pores called ______
Stoma
Which equations represent photosynthesis?
6CO2 + 6H2O —–> C6H12O6 + 6O2
In which of the following organelles does photosynthesis take place?
Chloroplast
What connects the 2 photosystems in the light reactions
An electron transport chain
What 2 molecules are produced by the light reactions and used to power the Calvin cycle?
ATP and NADPH
What provides electrons for the light reactions?
H2O
What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle?
Carbon Dioxide
What transports electrons from the light reactions to the calvin cycle?
NADPH
The light reactions take place in the _____ and the calvin cycle takes place in the ______
thylakoids; stroma
Which best describes the chemical equation for photosynthesis?
Water + Carbon Dioxide + energy = Sugar + Oxygen
How do we know green light is NOT absorbed by chlorophyll?
Green light is the wavelength of light that is reflected instead of absorbed by the chloroplasts.
Identify the role of oxygen in photosynthesis.
It is a waste product in the light reactions
What is the role of light in photosynthesis
It excites electrons
What molecules link the light reactions (stage 1 of photosynthesis) to the Calvin cycle (stage 2 of photosynthesis)?
The electron shuttles (ATP and NADPH)
The main purpose of the Calvin cycle is to produce ______
Sugar
Identify the role of carbon dioxide in photosynthesis
It’s splits to become incorporated into sugars
The bulk of the mass of a plant is made from ______
Sugars made in photosynthesis, which were made from carbon dioxide
During the Calvin cycle, plants use energy from ATP and NADPH to drive _____
The synthesis of sugar from carbon dioxide
Which of the following is a common energy currency in living cells that powers most living organisms?
ATP
How does ATP release energy that can be used by living cells?
By breaking a bond within an ATP molecule
What happens to the ATP molecule after it has been used to do work?
It loses a phosphate group and is converted to ADP
What is the main purpose of cellular respiration?
To produce ATP
The food you eat is processed during cellular respiration to produce stored chemical energy in the form of ____, with _____ and _____ as by-products
ATP; CO2; water
Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?
Glucose
Select the correct sequence of steps as energy is extracted from glucose during cellular respiration
glycolysis—>acetyl CoA —-> Citric acid cycle —-> electron transport chain
What is the correct general equation for cellular respiration?
C6H12O6 + 6O2 —> 6CO2 + 6H2O + ATP energy
Which of the following processes takes place in the cytosol of a eukaryotic cell?
glycolysis
In what organelle would you find acetyl CoA formation, the citric acid cycle, and the ETC?
Mithochondrion
What describes the citric acid cycle?
This process produces some ATP and carbon dioxide in the mitochondrion
Which describes the ETC?
This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration
Identify the stage of cellular respiration where glucose is split into 2 molecules of pyruvic acid.
Glycolysis
During which stage of cellular respiration is the majority of the ATP produced?
ETC
Which stage of cellular respiration requires oxygen that you breathe?
Both the citric acid cycle and the ETC require oxygen
What is the chemical equation for glucose?
C6H12O6
Which stage of cellular respiration uses O2?
the ETC
Cellular respiration requires fuel (glucose) and oxygen gas. The main process that produces these inputs is _____
photosynthesis
Which part(s) of cellular respiration require(s) oxygen gas?
the citric acid cycle and the ETC
What is/are the most important output(s) of glycolysis?
2 pyruvic acid and 2 NADH molecules
Unlike the Citric Acid cycle and electron transport, glycolysis occurs _____
in the cytoplasm
Glycolysis is the multi-step breakdown if ___. Several different ___ play a role in this process.
glucose….enzymes
Which part of cellular respiration takes place in the mitochondria?
The citric acid cycle and the ETC
What is the role of oxygen in cellular respiration?
Oxygen accepts high-energy electrons after they are stripped from glucose/
Cellular respiration accomplishes 2 major processes: (1) it breaks glucose down into smaller molecules, and (2) it harvests the chemical energy released and stores it in ATP molecules. By the end of ____, the breakdown of glucose is complete; most ATP molecules are produces during ____
the citric acid cycle…electron transport
NADH and FADH2 are important in cellular respiration because they deliver high-energy electrons to the electron transport system. Electron transport produces ___ ATP molecules per NADH molecule and _____ ATP molecules per FADH2 molecule
three…two
In electron transport, high-energy electrons “fall” to oxygen through a series of reactions. The energy released is used to _____
transport protons into the intermembrane space of the mitochondria, where they become concentrated. They then flow back out into the inner compartment (matrix) of the mitochondria. On the way back, protons turn ATP synthase turbines and produce ATP
Alcohol is a waste product produced by yeast in the presence of sugar and the absence of ______
O2
Upon fertilization, the egg and the sperm fuse to form a single cell called a(n)
zygote
Dead or damaged cells are replaced by the process of ____
mitosis
What process involving cell division results in daughter cells that are NOT identical to the parent cell?
Sexual reproduction
The DNA of every of eukaryotic cell is stored in one or more ______ located in the _____
chromosomes; nucleus
DNA and protein together form a complex called ____
chromatin
Before a cell divides, it copies all of its chromosomes. While the 2 copies of a chromosomes are attached they are called ____ _____
sister chromatids
Chromosomes contain most of the cell’s ____ which acts as the molecule of heredity
DNA
A duplicated chromosome remains tightly paired with its partner at a region called the ______
centromere
Human white blood cells are often multinucleated (in other words, have more than one nucleus). How many chromosomes would be present in a human would be present in a human white blood cell with 2 nuclei?
92
Is the number of chromosomes in each cell of an organism a good indicator of the complexity of that organism?
No, the number of chromosomes does not indicate how complex an organism is
DNA plus its associated proteins is called a _____
chromatin
Genes are located on ______
chromosomes
When are the chromosomes of a cell duplicated?
Before a cell divides
How many chromosomes and chromatics would a typical human cell after duplication but before mitosis?
46 chromosomes, 92 sister chromatids
Which is the correct sequence of events during mitosis?
Nuclear membrane dissolves, chromosomes line up, sister chromatids split, nuclear membrane forms
As mitosis begins, ______ _____ are linked together at the centromere
sister chromatids
What must happen before a cell can begin mitosis?
The chromosomes must be duplicated
The centromere move away from each other and the nuclear envelope breaks up during which phase of mitosis?
Prophase
The chromosomes line up in the center of the cell during which phase of mitosis?
Metaphase
The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?
Anaphase
The chromosomes arrive at the poles and nuclear envelopes from during which phase of mitosis?
Telophase
At the end of the mitotic (M) phase, the cytoplasm divides in a process called _______
cytokinesis
What specifically separates during anaphase of mitosis?
sister chromatids
What is cytokinesis?
The stage of the cell cycle after the cell has divided its DNA and during which the cytoplasm gets divided
When does the cell plate form during cell division?
At the completion of plant cell mitosis
How does cytokinesis occur in a dividing animal cell?
By the formation of a cleavage furrow
In sexually reproducing multicellular organisms, the main functions of mitosis are _____
-Growth and development
-Tissue repair/replacement of damaged cells
Which events occur during prophase?
-The nuclear envelope breaks down
- Chromosomes condense and are attached to spindle fibers
Cytokinesis ______
finishes mitosis by dividing the cytoplasm and organelles of the original parent cell into 2 separate daughter cells.
During ______, the cell carries out its normal functions and the chromosomes are thinly spread out throughout the nucleus
interphase
Looking through a light microscope at a dividing cell, you see two separate groups of chromosomes on opposite ends of the cell. New nuclear envelopes are taking shape around each group. The chromosomes then begin to disappear as they unwind. You are witnessing ______
telophase
What is the chromosome abnormally that causes Down syndrome
A nondisjunction results in a person with an extra copy of chromosome 21
What process can lead to an individual having too many or two few chromosomes
Nondisjunction
What is crossing over?
The exchange of pieces of homologous chromosomes
When does crossing over occur?
Meiosis I
Like mitosis, meiosis involves duplication of the chromosomes before division starts. However, there are _____ rounds of cell division during meiosis and _____ during mitosis
two; one
Which process requires DNA to undergo duplication before it can proceed?
Meiosis and Mitosis
What specifically separates during meiosis II?
Sister chromatids
What specifically separates during meiosis I?
Homologous chromosomes
The functions of meiosis is/are _____
reproduction (production of gametes)
Looking through a light microscope at a cell undergoing meiosis, you see that the chromosomes have joined into XX-shaped tetrads. These tetrads are lined up along a plane that runs through the center of the cell. This cell is in _____
meiosis I
Meiosis starts with _____ cells and produces ____ gametes
- diploid
- haploid
Meiosis is typically accomplished in _______
three steps. All of the chromosomes are duplicated in a diploid cell, and then there are two cell divisions to produce a total of 4 haploid gametes
The _____ separate in meiosis I; the _____ separate in meiosis II
homologous chromosomes…sister chromatids
If mitosis makes somatic cells, what does meiosis make?
Gametes
If a cell had 12 chromosomes at the beginning of meiosis II, how many would each daughter cell have after the completion of meiosis II?
12
Meiosis starts with a single diploid cell and produces….
4 haploid cells
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase
During prophase I of meiosis,
homologous chromosomes stick together in pairs
The correct order of events during meiosis is
prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II
During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?
prophase I
What is a karyotype?
A picture of all the chromosomes in one person’s cell
Somatic cells are ____
diploid (2n)
How many chromosomes did you inherit from your father?
23
