Science - UPCAT MSA Reviewer

All living things are made up of cells. Different cells and organs are adapted for their different roles in life processes. All living cells contain a nucleus, cytoplasm and a cell membrane. In addition to these, plant cells also have a cell wall, chloroplasts, and a vacuole. Which part of a cell contains the mitochondria?

cytoplasm

The part of a plant cell that stores water, sugar, and minerals:

vacuole

Photosynthesis is the process of converting light energy and inorganic compounds into chemical energy and organic compounds. This is the way plants make their own food. It happens mainly in the palisade cells of leaves, and is a complex chemical reaction requiring energy from light. Photosynthesis—

is essential to all life on earth

Plants need carbon dioxide, water, light and chlorophyll in order to make starch by photosynthesis. Carbon dioxide enters plants through holes in the leaves called—

stomata

Our diet must include three types of food: energy foods, body-building foods and maintenance foods. The main energy foods are carbohydrates and:

fats

Vitamins help to control chemical reactions in our bodies. Without vitamins certain reactions cannot take place. We need only tiny amounts of vitamins, but without them we will suffer from deficiency diseases; like the lack of vitamin D will lead to—

rickets

The heart pumps blood around the body through a system of tubes called blood vessels. Which blood vessels carry blood back to the heart?

veins

What is the function of the white blood cells?

to destroy bacteria in the body

What is the function of the excretory system?

to remove harmful waste produced by the body

In a species of pea plant, white flowers were completely dominant over red flowers. Pure-breeding, white-flowered pea plants are crossed with pure-breeding, red-flowered pea plants. What proportion of white- and red-colored plants will be produced in the F₁ generation?

all white-flowered plants

Of the following parts of a cell, which one is the smallest in size?

amino acid

Which of the following statements is true?

Chromosomes are made of DNA and contain genes.

Different organisms have different numbers of chromosomes. Kangaroos have 12 chromosomes in each body cell. This means that the number of chromosomes in each egg cell of a kangaroo is

6

Phenotype may be defined as

visible expression of genotype.

Alleles are genes which

occupy corresponding positions on homologous chromosomes.

Fine pollen grains on the surface of water are examined under a microscope. It is observed that the pollen grains are in random motion and frequently changing direction. The movement is most likely due to the

collisions between water molecules and pollen grains.

When ice changes from a solid to a liquid at its melting point

its particles gain energy.

When water changes into steam, the molecules become

more widely spaced.

Which of the following is a physical property of sugar?

it is a white crystalline solid.

It is the separation of a liquid into different substances with different boiling points.

distillation

A chemical reaction occurs when

dilute hydrochloric acid is added to magnesium ribbon.

Solids do not diffuse like gases because the particles of a solid

cannot move around each other.

Smoke particles are examined under a microscope, and was observed to be moving randomly. This movement is due to

air molecules bumping into smoke particles.

The reason why gases diffuse faster than liquids is that gas molecules are

more free to move than liquid molecules.

It is considered as the most primitive kingdom.

Monera

Two different forms of the same gene and are located on homologous chromosomes.

alleles

Enzymes are proteins that catalyze a particular biochemical reaction involving specific substrate molecules. Enzyme activity is affected by pH, that is

each enzyme works at different optimum level.

An embryo begins to develop from a zygote as a direct result of

cleavage

Which of the following is the function of the cotyledon in a seed?

to provide nutrients for the germinating plant

Which of the following may stimulate the growth of the roots in plant cuttings?

the use of auxins

Species can be best defined as

a group of organisms that mate with each other.

Evolution is best defined as

a process of change in organisms over a period of time.

Which of the following concepts is best described by the statement:

“Organisms with favorable variations reproduce more successfully than organisms with less favorable variations”?

survival of the fittest

The density of CCl₄ (carbon tetrachloride) is 1.58 g/mL. How much will 1 L of CCl₄ weigh?

1 580 g

Which of the following will change the boiling point of a liquid?

solid dissolved in a liquid

A neutral atom in the ground state contains 16 electrons. What is the total number of electrons in the 3p sublevel?

4

A light microscope contains two lenses that work together to magnify the image the observer is looking at. Name the part of the microscope that regulates the light that passes through the object that is mounted on the slide.

diaphragm

Atoms which are chemically the same but differ in their mass numbers are isotopes. Chlorine has two isotopes. The atomic structure of isotopes have

different number of neutrons.

A graduated cylinder is used to measure liquid volume. The correct way of reading the level of mercury in a graduated cylinder is

read from the bottom of the meniscus.

The two main parts of an atom are

nucleus and energy levels.

An orbital can never be occupied by

3 electrons

An electron-dot symbol consists of the symbol representing the element and an arrangement of dots that usually shows

the electrons in the outermost energy levels.

Elements are classified according to the

number of protons in its nucleus.

In the atomic nucleus of a certain element are 28 protons and 30 neutrons. The atomic number of the element is

86

The weight of an atom comes mostly from its

neutrons

Adding a catalyst to a reaction will change the

activation energy

The radioactive half-life of a certain isotope is 2 days. What part of this isotope will remain after 8 days?

1/8

The radioactivity we encounter comes mostly from

the natural environment

Most of the energy released in both nuclear fission and fusion is initially in the form of

the kinetic energy of recoiling particles

Mixtures can be classified as homogeneous or heterogeneous and can be separated by simple means. Solutions and suspensions

are both examples of a homogeneous mixture.

In the periodic table, the periods are represented by

columns

The elements in Group VII-A

are known as halogens.

When combined with metals, nonmetals tend to ___ electrons.

gain

The main reason why the inner transition elements are placed below the main body of the periodic table is that

such positioning makes the periodic table fit better on a sheet of paper.

Which of the following statements is false?

Reducing agents are oxidized in an oxidation-reduction reaction.

What do respiration, combustion and rusting have in common?

They are processes using up oxygen.

Decomposing water by an electric current will give a ratio of oxygen to hydrogen by volume equal to

2 : 1

A 20% solution of NaCl means that in 100 g of solution there is

20 g of NaCl

A salt derived from a weak acid and a strong base will undergo hydrolysis and give a solution that will be

neutral

The concept of kinetic energy per molecule is the same as the concept of

temperature

The inner part of the earth is kept hot by

radioactivity

The melting of snow in Siberia actually

tends to cool the atmosphere.

The main reason why one can possibly walk barefoot on red-hot wooden coals without burning the feet is

the low thermal conductivity of coal.

Soon after you remove a bottled mineral water from a cold refrigerator it becomes wet. This wetness is primarily due to

condensation

The temperature of water at the bottom of an ocean under an iceberg is

above freezing point

How many stars is/are there in our solar system?

1

Which pair of substances are pollutants produced by a petrol-burning engine?

carbon monoxide and lead compounds

The moon’s gravitational field strength is one sixth that of the earth. An object on earth has a mass of 600 kg and a weight of 6 000 N. What is the mass and weight of the object on the moon?

600 kg and 1 000 N

Most of the minerals in the Earth’s crust belong to which of the following groups?

oxides

In minerals, it is very common for atoms to gain or lose electrons to form electrically charged ions. Which of the following bonds resulted from the attraction between the positively charged ions and the negatively charged ions?

ionic

Which of the following explains why the troposphere is warmest near the earth’s surface?

The earth’s surface reradiates the solar energy which heats the troposphere.

It is the region of the atmosphere which absorbs harmful ultraviolet radiation.

ozone layer

What is likely to happen if the moisture in the lower layers of an air mass is increased and heat energy is added?

It will create instability.

An “astronomical unit” is

the average distance from the earth to the sun which is 1.495 × 10¹¹ m.

The reason why we see eclipses of the Moon more often than solar eclipses even though solar eclipses happen more frequently is that

lunar eclipses are visible over more than half of Earth compared to less than 20% of Earth’s surface for partial solar eclipses.

Scientists think of the Earth as a system meaning that it consists of a number of related parts that interact in some way. The Earth’s system include the Earth-universe system, the atmosphere, the hydrosphere, the biosphere, and the solid Earth. None of these systems operates in isolation; all interact to some degree. Habitats in the biosphere are found in all of the following EXCEPT:

the Earth’s mantle

Minerals, like all other materials, are made up of atoms and are solids possessing orderly internal arrangements of atoms. This means that minerals are

crystalline

Minerals, like gold, diamond and sulfur, are known as native elements. Native elements are

made up of only one element.

Igneous rocks originate when magma or lava cools and crystallizes or when pyroclastic materials are consolidated. The two categories of igneous rocks are plutonic rocks, which form within the earth’s crust, and volcanic rocks, which form at the surface. Volcanic rocks can usually be distinguished from plutonic rocks by

the size of its mineral crystals

In the process of evaporation, liquid molecules of water become molecules of water vapor. Water evaporates most readily under the following conditions.

hot, dry with a lot of wind

Mechanical and chemical weathering result in disintegration and decomposition of parent material so that it is more nearly in equilibrium with new physical and chemical conditions. Mechanical weathering involves forces that break rocks into smaller pieces without changing chemical composition. Which mechanical weathering process is involved in the origin of exfoliation domes?

pressure release

A slope’s shear strength (mountain slope) depends on the slope material’s strength and cohesiveness and on the amount of internal friction between grains. These factors promote slope stability. Which of the following factors can actually enhance the slope stability?

vegetation

Ground water moves very slowly to outlets such as streams, lakes, swamps, and eventually completing the hydrologic cycle by returning to the oceans. It may be discharged at the surface when a spring forms where the water table intersects the ground surface. What is the rate of discharge flow of a stream with a cross-sectional area of 168 m² and an average flow of 16 m/sec?

2 688 m³/s

Stars form when dense clouds of interstellar gas and dust begin to contract under their own gravity. Eventually, the contracting cloud, or protostar, becomes hot and dense enough for nuclear reactions to begin within. Stars shine stably until their hydrogen runs out. The sequence of evolution of a typical star is best described as

protostar, main sequence, red giant, white dwarf

An object is in uniform motion if it travels in a straight line at constant speed. All other motions are accelerated. Acceleration can involve changes of speed, changes of direction, or both. Which of the following is in uniformly accelerated motion?

A car going around a circular curve at uniform speed of 88 kph.

Newton’s first law of motion states that “Every object remains at rest or in motion in a straight line at constant speed unless acted upon by an unbalanced force.” What is the net force acting on an airplane in level flight at 500 kph due north?

0

Newton’s second law of motion states that “The net force of an object is equal to its mass times its acceleration and points in the direction of the acceleration.” What is the weight of a weight-lifter who has a mass of 120 kilograms?

1 200 N

Assuming the frictional force to be zero when the car hits an oil slick. Describe the resulting motion of the car.

The car will slide in straight line in the direction it was traveling at the time it hits the oil slick.

A bird is flying upward at an angle of 45° with the horizontal. The direction of the force of gravity acting on it is

downward

An object is in equilibrium,
I. if it is at rest.
II. if it is moving at a constant velocity only.
III. if it is in free fall.

I and II only

If a car is moving along at constant speed in a straight line, it may be assumed that

the sum of all horizontal forces is zero.

Objects in an orbiting spacecraft is weightless because

the spacecraft is in free fall