Bio and Chem (Grade 10)

Multiple Choice Practice Questions

DNA and Genetics

• 35% of DNA bases are Guanine (G).
• If 35% of DNA bases are G, then the remaining 65% are divided between A, C, and T.
• A change in the base sequence of DNA is a correct description of a gene mutation.
• If a chromosome has 6125 pairs of bases and 2345 of the bases are G, then the number of bases that are T is 3780.

Inheritance and Pangolins

• The allele for yellow flowers is dominant to the allele for red flowers.
• If two heterozygous yellow-flowered plants are crossed, 75% of the offspring will have yellow flowers and 25% will have red flowers.
• Pangolins are mammals, and one species of pangolin has 40 chromosomes per body cell.
• A sperm cell from this species of pangolin will have 20 chromosomes.

Pedigree Diagrams and Sickle Cell Anaemia

• A pedigree diagram shows the inheritance of a recessive condition.
• In the pedigree diagram, P and Q are both heterozygous for the condition.
• Q and R have different genotypes.
• P and R have the same genotype.
• Heterozygous individuals are more resistant to malaria.

DNA Structure

• The sequence of bases on one strand of DNA is ATTGGACGGT.
• The sequence of bases on the opposite strand is TAACCTGCCA.

Chromosomes and Fertilisation

• Kangaroos have 16 chromosomes in their skin cells.
• A kangaroo sperm cell has 8 chromosomes.
• A gene contains only the information to produce a specific protein.
• Fertilisation is the combining of male and female nuclei.

Organization of the Human Body

• The correct level of organisation, from simplest to most complex, is: red blood cell, heart muscle, heart, circulatory system.

DNA, Chromosomes, and Fertilisation

• The structure of DNA involves two strands coiled together to form a double helix.
• The correct pairing of bases between the two strands is: A and T, C and G.

Chromatogram and Compounds

• A chromatogram shows the separation of substances based on their properties.
• The pure substance with the largest R1 value is D.
• Compounds are made up of two or more different elements chemically bonded together.
• Compounds cannot be broken down into simpler substances by physical processes.
• Compounds and their elements have different properties.

Cryolite and In Vitro Fertilisation

• Cryolite is a mineral that contains aluminium, sodium, and fluorine.
• The formula of cryolite is Na3AlF6.
• In vitro fertilisation (IVF) is available to everyone.
• IVF provides an opportunity for single parents to have a family.
• Sperm or egg donation may be involved in IVF.

Atoms and Molecules

• W, X, Y, and Z are diagrams representing atoms and molecules.
• W, Y, and Z are molecules, and X is an atom.

Sodium Phosphate, Aluminium Sulfate, and Aluminium Phosphate

• Sodium phosphate, Na3PO4, contains sodium ions, Na+.
• Aluminium sulfate, Al2(SO4)3, contains sulfate ions, SO42-.
• The formula of aluminium phosphate is Al2(PO4)3.

Water, Chalk, and Salt

• A sample of water is contaminated with insoluble chalk and a soluble salt.
• The two processes used to separate the water from the chalk and salt are filtration and crystallisation.

Ammonia (NH3)

• The dot and cross diagram that represents a molecule of ammonia (NH3) has one black dot in the center where the 3 circles overlap, and one black dot on the edge of the circle to the left of the overlapping center.

Cell Structure and Function

• Mitochondria is the organelle responsible for producing energy in the cell.

Genetics

• The expected phenotypic ratio of a monohybrid cross between two heterozygous individuals (Tt x Tt) is 3:1.

Photosynthesis

• Chlorophyll is the primary pigment involved in photosynthesis.

Human Anatomy

• The Circulatory System is responsible for transporting oxygen and nutrients to cells in the human body.

Evolution

• Natural Selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring.

Periodic Table

• Fluorine has the highest electronegativity among the elements.

Chemical Reactions

• A Neutralization Reaction occurs when an acid reacts with a base to produce salt and water.

Stoichiometry

• 2 moles of hydrogen gas react with 1 mole of oxygen gas to produce 2 moles of water.

States of Matter

• Sublimation is the phase change that involves the transformation from solid directly to gas.

Organic Chemistry

• The general formula for alkanes is CnH2n+2.

Chromosomes and Cells

• Kangaroos have 16 chromosomes in their skin cells.

DNA Structure

• The structure of DNA involves two strands coiled together to form a double helix.
• The correct pairing of bases in DNA is A and T, and C and G.

Genetics

• A homozygous individual has two of the same alleles for a characteristic.
• In a pedigree diagram, individuals with a condition are represented by filled-in shapes.
• Sickle cell anemia is a genetic disorder caused by a recessive allele.

Inheritance

• In a monohybrid cross between two heterozygous individuals, the expected phenotypic ratio is 3:1.

Lab Techniques

• Chromatography is used to separate a mixture of colored compounds.

Photosynthesis

• The primary pigment involved in photosynthesis is not carotene.

Cell Biology

• Mitochondria are responsible for producing energy in the cell.

Genetics

• The expected phenotypic ratio of a monohybrid cross between two heterozygous individuals (Tt x Tt) is 3:3:3:1.

Photosynthesis

• The primary pigment involved in photosynthesis is chlorophyll.

Human Body Systems

• The circulatory system is responsible for transporting oxygen and nutrients to cells.

Evolution

• The process by which organisms better adapted to their environment tend to survive and produce more offspring is called natural selection.

Chemistry

• Fluorine has the highest electronegativity on the periodic table.

Chemical Reactions

• When an acid reacts with a base to produce salt and water, it undergoes a neutralization reaction.

Chemistry Formulas

• Cryolite, a mineral containing aluminum, sodium, and fluorine, has the chemical formula Na₃AlF₆.

Chemical Compounds

• Sodium phosphate, Na₃PO₄, contains sodium ions, Na+.
• Aluminum sulfate, Al₂(SO₄)₃, contains sulfate ions, SO₄²⁻.
• The formula of aluminum phosphate is AlPO₄.

Laboratory Techniques

• Chromatography is a process used to separate a mixture of colored compounds.