Semester 2 Exam Revision

What is the S.I. unit for mass?

The S.I. unit for mass is the kilogram (kg).

What is the S.I. unit for time?

The S.I. unit for time is the second (s).

Name common metric multipliers for measurements:

Micro- (10^-6), milli- (10^-3), centi- (10^-2), kilo- (10^3), mega- (10^6), giga- (10^9).

What is the difference between scalar and vector quantities?

Scalar quantities have only magnitude (e.g., speed), while vector quantities have both magnitude and direction (e.g., velocity).

What is distance?

Distance is a scalar quantity that refers to the total path length traveled by an object.

What is displacement?

Displacement is a vector quantity that refers to the change in position of an object from its initial to final position.

How do you calculate distance and displacement in 1D and 2D motion?

Distance is the total length of the path taken, while displacement is the straight-line distance from the initial to the final position, calculated using vector diagrams where applicable.

How do you calculate true bearing of vector quantities?

True bearing can be calculated using trigonometric functions (e.g., sine and cosine) based on the components of the vector.

What is speed?

Speed is a scalar quantity that measures how fast an object is moving, defined as distance divided by time.

What is velocity?

Velocity is a vector quantity that describes the rate of change of displacement, defined as displacement divided by time.

What is the average speed formula?

Average speed is calculated using the formula: Average Speed = Total Distance / Total Time.

What is the average velocity formula?

Average velocity is calculated using the formula: Average Velocity = Total Displacement / Total Time.

Define acceleration.

Acceleration is the rate of change of velocity with respect to time.

What is the formula for acceleration?

Acceleration 'a' can be calculated using the formula: a = (v – u)/t.

What is the formula to find the final velocity?

The final velocity 'v' can be obtained using the equation: v = u + at.

What is the equation for distance with uniform acceleration?

Distance 's' can be calculated using the formula: s = ut + ½ at².

What is the equation for final velocity related to distance?

The relation between final velocity and distance is given by: v² = u² + 2as.

What can displacement-time graphs show?

Displacement-time graphs display an object's motion, indicating its displacement over time.

How can you determine speed from a displacement-time graph?

The speed of an object can be calculated from the slope of a displacement-time graph.

How can you find displacement from a velocity-time graph?

Displacement can be determined by calculating the area under the velocity-time graph.

How can you find acceleration from a velocity-time graph?

The acceleration of an object can be found using the gradient (slope) of a velocity-time graph.

What is the acceleration due to gravity?

The acceleration due to gravity is approximately 9.81 m/s².

Define force and its SI unit.

Force is any interaction that changes the motion of an object, and its SI unit is the newton (N).

What is resultant force?

Resultant force is the single force that represents the vector sum of all the forces acting on an object.

What is inertia?

Inertia is the tendency of an object to resist changes in its state of motion.

State Newton’s 1st Law.

An object at rest remains at rest and an object in motion continues in motion at a constant velocity unless acted upon by a net external force.

State Newton’s 2nd Law.

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, expressed as F = ma.

How is weight defined?

Weight is defined as the gravitational force acting on an object, calculated using the formula W = mg.

What is Newton’s 3rd Law?

For every action, there is an equal and opposite reaction.

What is work in physics?

Work is done when a force acts upon an object to move it in the direction of the force.

What is the formula that relates work to force and distance?

The relationship of work is given by W = Fs, where W is work, F is force, and s is distance.

Define energy and its SI unit.

Energy is the capacity to do work, and its SI unit is the joule (J).

How is energy expressed?

Energy cannot be seen, only detected when a change occurs.

What are some forms of energy?

Energy exists in many forms, including heat, mechanical, chemical, electrical, light, sound, nuclear, potential, and kinetic energy.

What is energy transformation?

Energy transformation is the process of converting one form of energy into another.

Differentiate between energy transfer and transformation.

Energy transfer involves moving energy from one object to another, while energy transformation involves changing energy from one form to another.

Define Kinetic Energy.

Kinetic energy (EK) is the energy of motion, calculated with the formula EK = ½ mv².

Define Gravitational Potential Energy.

Gravitational potential energy (EP) is the energy held by an object because of its position in a gravitational field, calculated with the formula EP = mgh.

What are the two types of mechanical energy?

Mechanical energy can be either potential energy or kinetic energy.

What is the law of conservation of energy?

The law of conservation of energy states that energy cannot be created or destroyed, only transformed or transferred.

Define power and its SI unit.

Power is the rate at which work is done, and its SI unit is the watt (W).

What is the power formula?

Power can be calculated using the formula P = W/t, where W is work done and t is time taken.

What is efficiency in energy?

Efficiency measures how much useful energy is converted versus the total energy supplied, often expressed as a percentage.

What are the key components of an animal cell?

Key components include the cell membrane, cytoplasm, nucleus, and various organelles such as mitochondria, endoplasmic reticulum, and ribosomes.

What are the key components of a plant cell?

Key components include the cell membrane, cell wall (unique to plant cells), cytoplasm, nucleus, and organelles like chloroplasts, vacuoles, and ribosomes.

What is the role of DNA in a cell?

DNA carries genetic information used in growth, development, and reproduction of organisms.

Describe the structure of DNA.

DNA is made of nucleotides that consist of a sugar, phosphate, and nitrogen base (adenine, thymine, cytosine, guanine) arranged in a double helix.

Who are Watson and Crick?

James Watson and Francis Crick are credited with the discovery of the double helix structure of DNA.

What is a gene?

A gene is a segment of DNA that contains instructions for building proteins, which determine traits.

What is protein synthesis?

Protein synthesis is the process by which cells translate genetic information into proteins.

What occurs during DNA replication?

During DNA replication, enzymes like DNA helicase and DNA polymerase facilitate the unwinding and duplication of DNA.

What is mitosis?

Mitosis is a type of cell division that results in two identical daughter cells, used for growth and repair.

What are the stages of mitosis?

The stages of mitosis include prophase, metaphase, anaphase, and telophase.

What is the difference between haploid and diploid cells?

Diploid cells have two sets of chromosomes, one from each parent, while haploid cells have only one set.

What are homologous chromosomes?

Homologous chromosomes are pairs of chromosomes that are similar in shape, size, and genetic content.

What is meiosis?

Meiosis is a process of cell division that produces four genetically diverse haploid cells, essential for sexual reproduction.

What are the stages of meiosis?

The stages of meiosis include meiosis I (prophase I, metaphase I, anaphase I, telophase I) and meiosis II (prophase II, metaphase II, anaphase II, telophase II).

What are the similarities and differences between mitosis and meiosis?

Both processes involve cell division, but mitosis produces two identical diploid cells, while meiosis produces four unique haploid cells.

Who is Gregor Mendel?

Gregor Mendel is known as the father of genetics for his work on the inheritance of traits in pea plants.

What is genetic information?

Genetic information is inherited from both parents and is passed on through meiosis and fertilization.

What is the difference between a gene and an allele?

A gene is a segment of DNA coding for a trait, while an allele is a variant form of a gene.

What is the difference between dominant and recessive traits?

Dominant traits are expressed in the phenotype even if only one allele is present, while recessive traits are only expressed when two copies are present.

What are genotype and phenotype?

Genotype refers to the genetic makeup of an organism, while phenotype refers to the observable characteristics.

What are homozygous and heterozygous genotypes?

A homozygous genotype has two identical alleles, while a heterozygous genotype has two different alleles for a trait.

What is a Punnett square?

A Punnett square is a diagram used to predict the genetic outcomes of a cross between two organisms.

How does sex determination occur in humans?

Sex determination in humans is based on the presence of X or Y chromosomes, with XX being female and XY being male.

What is a karyotype?

A karyotype is an organized profile of an individual's chromosomes.

What is the difference between male and female karyotypes?

Male karyotypes typically have one X and one Y chromosome, while female karyotypes have two X chromosomes.

How do you identify chromosomal abnormalities?

Chromosomal abnormalities can be identified by examining the number and structure of chromosomes in a karyotype.

What are autosomes and sex chromosomes?

Autosomes are non-sex chromosomes, while sex chromosomes are involved in determining the sex of an individual.

What are simple ratios in genetics?

Simple ratios describe the expected ratio of offspring genotypes and phenotypes from genetic crosses.

What is a pedigree?

A pedigree is a diagram depicting the inheritance of traits across generations in a family.

How are individuals identified in a pedigree?

Individuals in a pedigree are identified using Roman numerals for generations and numbers for individuals within those generations.

How do you determine genotypes and phenotypes in a pedigree?

Genotypes and phenotypes can be determined by analyzing the inheritance patterns shown in the pedigree.

What is meant by mode of inheritance?

Mode of inheritance refers to whether a trait is autosomal or sex-linked, and whether it is dominant or recessive.

How can you predict trait inheritance from a pedigree?

The probability of inheriting a trait can be predicted using patterns observed in pedigree analysis.

What is species variation?

Variation in species refers to the differences in traits among individuals within a species.

What are gene mutations?

Gene mutations are alterations in the nucleotide sequence of a gene that can affect protein synthesis.

What are examples of mutagens?

Mutagens are agents that cause mutations, examples include radiation, chemicals, and certain viruses.

What is a population in genetics?

A population is a group of individuals of the same species that live in a particular area and interbreed.

What is a gene pool?

A gene pool is the total collection of genes in a population at a given time.

What does allele frequency mean?

Allele frequency refers to how often a particular allele appears in a population relative to other alleles.

How can allele frequencies change?

Allele frequencies can change due to mutations, migration, and environmental pressures.

What is evolution?

Evolution is the process by which populations change over generations through variations and natural selection.

What is natural selection?

Natural selection is the mechanism by which organisms better adapted to their environment tend to survive and produce more offspring.

What is speciation?

Speciation is the evolutionary process by which populations evolve to become distinct species.

How does evidence from fossils support evolution?

Fossils and comparative studies in anatomy, embryology, DNA, and proteins provide evidence for common ancestry and evolutionary changes.

What is the SI unit for length

Metres (m)