Biology

1. 1
Prepared by; Miss ANZAL FAIQA YOUSUF (M.S.c BOTANY I.U.B)
S.S.A ( Siddique Science Academy)
10/C officers Colony Bahawalnagar ( Contect# 03338810387, 03000831969)
BIOLOGY 9Th
Unit -7 BIOENERGETICS
1:In which of the following steps of respiration,CO2 is produced?
{A} Glycolysis {B} Krebs cycle
{C} Electron transport chain {D} All of these
2: Oxygen takes part in aerobic respiration in;
{A} Glycolysis {B} Link step between Glycolysis and krebs cycle
{C} krebs cycle {D} Electron transport chain
3: When a plant was kept in darkness for many days, it leaves turned yellow, Why?
{A} leave could not get oxygen and so there was no photosynthesis
{B} leave could not get light and so there was no respiration
{C} leave could not get oxygen and so there was no respiration
{D} leave could not get light and so there was no photosynthesis.
4: From which bonds of ATP molecules energyis taken?
{A} P-P bonds {B} C-H bonds {C} C-N bonds {D} C-O bonds
5: In which components of the leaf cells, chlorophyll is present.
{A} Stroma {B} Thylakoids {C} Plasma membrane {D} Cytoplasm
6: Which of these can enter into Krebs cycle?
{A} Glucose {B} Pyruvic acids {C} Citric acid {D} Asetyl Co-A
7: When we work hard we suffer from muscles fatigue because muscle cells;
{A} Carry out aerobic respiration at faster rate and so are tired.
{B} Carry out anaerobic respiration at faster rate and so accumulate more CO2
{C} Carry out anaerobic respiration at faster rate and so accumulate lactic acid.
{D} Carry out aerobic respiration and so accumulate lactic acid.
8: How many molecules of CO2 are produced when Krebs cycle operates once?
{A} 01 {B} 02 {C} 03 {D} 06
9:In which of the following metabolic processes, oxidation as well as reduction of
molecules occur?
{A} photosynthesis {B} Respiration {C} both {D} none of these
10:Chlorophyll pigments absorbs maximum light in wavelength of
CH-(7) MCQ’S

2. 2
Prepared by; Miss ANZAL FAIQA YOUSUF (M.S.c BOTANY I.U.B)
S.S.A ( Siddique Science Academy)
10/C officers Colony Bahawalnagar ( Contect# 03338810387, 03000831969)
BIOLOGY 9Th
{A} Green and blue {B} Green and Red
{C} Green only {D} Red and blue
11:Plants and some microorganisms prepare their food from carbon dioxide and
water in the presence of light by a process called_______
{A} Metabolism {B} Respiration
{C} Photosynthesis {D} Enzymes
12: Animals ,fungi and many microorganisms get the ___________food.
{A} cooked {B} prepared
{C} boiled {D} uncooked food
13: Food contains _______energy in its bonds.
{A} kinetic {B} solar
{C} potential {D} none of all
14:The potential energystored in __________ is again transformed in to kinetic energy
to carry out life activities.
{A} ADP {B} ATP
{C} AMP {D} NADP
15: ATP was discovered in ___________________
{A} 1929 {B} 1941
{C} 1829 {D} 1914
16: ATP was discovered by_____________.
{A} Fritz Lipmann {B} Karl Lohmann
{C} Malvin Calvin {D} Hans Krebs
17: ATP was proposed to be the main energytransfer molecule in the cell in __
{A} 1929 {B} 1941
{C} 1829 {D} 1914
18: ATP was proposed to be the main energytransfer molecule in the cell by_
{A} Fritz Lipmann {B} Karl Lohmann
{C} Malvin Calvin {D} Hans Krebs

3. 3
Prepared by; Miss ANZAL FAIQA YOUSUF (M.S.c BOTANY I.U.B)
S.S.A ( Siddique Science Academy)
10/C officers Colony Bahawalnagar ( Contect# 03338810387, 03000831969)
BIOLOGY 9Th
19: ______is the movement of water from a dilute solution to the concentrated one
through a membrane
A} Osmosis {B} Photosynthesis
{C} Oxidation {D} Calvin cycle
20: __covers only1-2 % of the leaf surface but they allow much air to pass through.
{A} Chlorophyll {B} petals
{C} Stomata {D} Stem
Q1: Define Bioenergetics?
Ans: Bioenergetics is the study of energy relationship and energy transformations in living
organisms.
Q2: Define oxidation reduction reactions or Redox reactions?
Ans: Redox reactions involve exchange of electrons between atoms. In living organism
redox reactions involves the loss and gain of hydrogen atoms. It losses an electron which is
called oxidation and gains hydrogen atom which is called reduction
Q3: Define Adenosine triphosphate?
Ans: The major currency of all cells is a nucleotide called adenosine triphosphate (ATP),it is
the main source of majority of the cellular functions.
Q4: Write down the ATP, the cell’s energycurrency?
Ans: The major currency of all cells is a nucleotide called adenosine triphosphate (ATP).It is
the main energy source for majority of the cellular functions like synthesis of
macromolecules, movements, transmission, exocytosis and endocytosis etc.
Q5: Write down the structure of ATP?
Ans: Each ATP molecule has three subunits;
(1):Adenine a double-ringed nitrogenous base.
(2)A ribose a five carbon sugar.
(3)Three phosphate groups in a linear chain
Ch#(7)Give Short Answers
DNASTRUCTURE
HydrogenBonding
ATP Diagram

4. 4
Prepared by; Miss ANZAL FAIQA YOUSUF (M.S.c BOTANY I.U.B)
S.S.A ( Siddique Science Academy)
10/C officers Colony Bahawalnagar ( Contect# 03338810387, 03000831969)
BIOLOGY 9Th
Q5: Define Photosynthesis?
Ans: Photosynthesis is the synthesis of glucose from carbon dioxide and water in the
presence of sunlight and chlorophyll, with oxygen as by product products. Photosynthesis is
an anabolic process and is important component of bioenergetics in living system. It is the
most important biochemical pathway and nearly all life depends on it. It comprises many
coordinated biochemical reactions that occur in plants, some algae and some bacteria. A
simple equation of this reaction is as follow;
6 CO2 + 12 H2O + Light energy chlorophyll
C6H12O6 + 6O2 + 6H2O
Q6: Define Light reaction?
Ans: Light energy is captured and is used to make high energy molecules ATP and NADPH.
These reactions are called light reactions.
Summary: the summary of light reactions is as follows;
1. When chlorophyll molecules absorb light, their energy level increases and their electrons
are emitted.
2. Electrons are passed to electrons transport chain to produce ATP.
3. Light also breaks water molecules and oxygen is released. The hydrogen atoms of water
give electrons to chlorophyll and become ions.
4. The electron of chlorophyll, after the production of ATP, and the hydrogen ions of water
are used for the reduction of NADP in to NADPH.
Q7: Define dark reaction? or (Calvin Cycle)
Ans: Carbon dioxide is reduced to make glucose. In this phase the energy from high energy
molecules (ATP and NADPH) is utilized. Since these reactions do not use light directly, they
are known as dark reactions.
Summary: the summary of the events of dark reactions also known as kelven cycles which
are as follows;
1. CO2 molecules are combined with 5-carbon compounds to form temporary 6 carbon
compounds, each of which splits in to 3 carbon compounds.
2. The 3- carbon compounds are reduced to 3–carbon carbohydrates by using ATP and
hydrogen from NADPH.The 3-carbon carbohydrates are used to manufacture glucose.
3. The 3-carbon carbohydrates are also used to regenerate the original 5-carbon
compounds. This step also utilizes ATP.
Q8: Define photo systems?
Ans: Photosynthetic pigments are organized in the form of clusters, called photo systems, in
thylakoids membranes of chloroplasts.

5. 5
Prepared by; Miss ANZAL FAIQA YOUSUF (M.S.c BOTANY I.U.B)
S.S.A ( Siddique Science Academy)
10/C officers Colony Bahawalnagar ( Contect# 03338810387, 03000831969)
BIOLOGY 9Th
Q9: Define accessorypigments?
Ans: Chlorophyll–a is the main photosynthetic pigment. Other are called accessory
pigments and include chlorophyll-b and arytenoids.
Q10: Define cellular respiration?
Ans: The cellular energy –yielding process is called cellular respiration.
Q11: Define aerobic respiration?
Ans: The cellular respiration occurs in the presence Oxygen is called aerobic respiration.
Q12: Define anaerobic respiration?
Ans: The cellular respiration occurs in the absence of Oxygen is called aerobic respiration.
Q13: Alcoholic fermentation?
Ans: It occurs in bacteria, yeast etc, in this type of anaerobic respiration, Pyruvic acid is
further broken down in to alcohol (C2H5OH) and CO2.
Pyruvic acid Ethyl Alcohol + Carbon dioxide
Q14: Lactic acid fermentation?
Ans: It occurs in skeletal muscles of humans and other animals during extreme physical
activities .This also happens in the bacteria present in milk. In this type of anaerobic
respiration each Pyruvic acid molecule is converted in to lactic acid ((C2H6O3 )
Pyruvic acid Lactic acid.
Q15: Define limiting factor?
Ans :Any environmental factor the absence of which can decrease the rate of a metabolic
reaction is called limiting factors of that reaction. Many factors like the light intensity,
temperature, concentration of carbon dioxide and availability of water act as limiting factors
for photosynthesis
Q1: Write down the role of chlorophyll and light on photosynthesis?
Ans: Sunlight energy is absorbed by chlorophyll. It is then converted in to chemical energy,
which drives the photosynthetic process. Only about one percent of the light falling on the
leaf surface is absorbed the rest is reflected .The light rays of different wavelengths are not
only different absorbed by photosynthetic pigments, but are also differently effective in
photosynthesis. The blue and red light carry out more photosynthesis. Chlorophylls
absorbed mainly blue and red light. Some wave lengths not absorbed by chlorophyll “a” are
very effectively absorbed by accessory pigments and vice –versa.
Ch#(7) Long Questions

6. 6
Prepared by; Miss ANZAL FAIQA YOUSUF (M.S.c BOTANY I.U.B)
S.S.A ( Siddique Science Academy)
10/C officers Colony Bahawalnagar ( Contect# 03338810387, 03000831969)
BIOLOGY 9Th
Q2: Write down the limiting factors in photosynthesis?
Ans: Limiting factor
Any environmental factor the absence of deficiency of which can decrease the rate of a
metabolic reaction is called limiting factor for that reaction. Many factors like light intensity,
temperature, concentration of carbon dioxide and availability of water act as limiting factors
for photosynthesis.
1:Effect of light intensity: The rate of photosynthesis varies with light intensity. It
decreases as light intensity decreases and increases as intensity increases. However at
much higher light intensity the rate of photosynthesis becomes constant.
2:Effect of temperature: The rate of photosynthesis decreases with decrease in
temperature. It increases as temperature is increased over a limited range. But if light
intensity is low, increasing the temperature has little influence on the rate of photosynthesis.
3:Effect of carbon dioxide concentration: As carbon dioxide rises, the rate of
photosynthesis goes on increasing until limited by other factors. Increase in carbon dioxide
concentration beyond a certain level causes the closure of stomata and it decreases the rate
of photosynthesis.