science extras

Question 1

What is the most specific level of biological classification?

Answer 1

Species

Species refers to a group of organisms that can interbreed and produce fertile offspring.

Question 2

What is the most general level of biological classification?

Answer 2

Kingdom

The kingdom encompasses multiple phyla.

Question 3

What is the correct order of biological classification from broad to specific?

Answer 3

Kingdom, Phylum, Class, Order, Family, Genus, Species

This order can be remembered with the mnemonic ‘King Phillip Cried Out For Goodness Sakes’.

Question 4

What falls directly below the kingdom in biological classification?

Answer 4

Phylum

The correct order is Kingdom → Phylum → Class → Order → Family → Genus → Species.

Question 5

What level groups similar species?

Answer 5

Family

Families group similar species based on shared traits.

Question 6

What is directly above the organ level in biological structures?

Answer 6

Organ systems

Organ systems consist of multiple organs working together.

Question 7

What is made up of cells?

Answer 7

Tissues

Tissues are composed of similar cells that work together to perform a function.

Question 8

What modifies polysaccharides and glycoproteins?

Answer 8

Golgi apparatus

The Golgi apparatus modifies, sorts, and packages macromolecules.

Question 9

What is the function of the vacuole in plant cells?

Answer 9

Stores water, nutrients, and waste

The vacuole also maintains turgor pressure in plant cells.

Question 10

Which phase of meiosis is characterized by the separation of homologous chromosomes?

Answer 10

Anaphase I

In Anaphase I, homologous chromosomes (pairs of maternal and paternal chromosomes) are separated and pulled to opposite poles. This is different from Anaphase II, where sister chromatids separate.

Question 11

In which stage of mitosis do the centromeres split and sister chromatids separate?

Answer 11

Anaphase

During Anaphase, the centromeres split, allowing the sister chromatids to be pulled to opposite poles by spindle fibers, ensuring that each daughter cell receives an identical set of chromosomes.

Question 12

Which of the following processes reduces the chromosome number by half?

Answer 12

Meiosis

Meiosis reduces the chromosome number from diploid (2n) to haploid (n), ensuring that gametes (sperm and egg cells) contain only half the genetic material, which is restored upon fertilization.

Question 13

In which stage of mitosis does the cleavage furrow or cell plate begin to form?

Answer 13

Telophase

During Telophase, the nuclear envelope re-forms, and the cleavage furrow (in animal cells) or cell plate (in plant cells) begins to develop, preparing the cell for cytokinesis.

Question 14

During which phase of meiosis do tetrads form and crossing over occurs?

Answer 14

Prophase I

Tetrads (pairs of homologous chromosomes) form during Prophase I, allowing for crossing over, which increases genetic diversity by exchanging segments between homologous chromosomes.

Question 15

Which event is unique to meiosis and is not seen in mitosis?

Answer 15

Synapsis of homologous chromosomes

Synapsis is the pairing of homologous chromosomes during Prophase I of meiosis, allowing for crossing over, which does not occur in mitosis.

Question 16

In which phase of mitosis does the nuclear envelope disintegrate and chromosomes become visible?

Answer 16

Prophase

During Prophase, chromatin condenses into visible chromosomes, and the nuclear envelope breaks down, allowing spindle fibers to attach to the chromosomes.

Question 17

Which phase of meiosis involves the alignment of tetrads at the center of the cell?

Answer 17

Metaphase I

During Metaphase I, homologous chromosome pairs (tetrads) line up at the metaphase plate, ensuring proper segregation during Anaphase I.

Question 18

During which phase of mitosis do sister chromatids become maximally condensed and clearly visible under the microscope?

Answer 18

Prophase

Prophase is when chromosomes condense and become distinct under a microscope, making them easy to observe for structural analysis.

Question 19

At the end of Meiosis I, the resulting cells are:

Answer 19

Haploid and genetically different

Meiosis I results in two haploid cells, each containing half the original chromosome number. These cells are genetically unique due to crossing over and independent assortment.

Question 20

In mitosis, what ensures that each daughter cell gets a complete set of chromosomes?

Answer 20

DNA replication during interphase

DNA is replicated during the S phase of interphase to ensure that, after mitosis, each daughter cell receives a full set of identical chromosomes.

Question 21

Which phase of meiosis introduces genetic variability through the random alignment of maternal and paternal chromosomes?

Answer 21

Metaphase I

During Metaphase I, homologous chromosomes align randomly along the metaphase plate. This independent assortment contributes to genetic variation.

Question 22

In meiosis, when do homologous chromosomes pair up?

Answer 22

Prophase I

During Prophase I, homologous chromosomes pair up and form tetrads, allowing crossing over to occur, which contributes to genetic diversity.

Question 23

What is the primary function of mRNA?

Answer 23

Translation

mRNA carries genetic information from DNA and serves as a template for protein synthesis during translation.

Question 24

How many genes do humans approximately have?

Answer 24

20,000

Humans have about 20,000-25,000 genes, coding for various proteins and regulating biological processes.

Question 25

If a trait is NOT expressed in the presence of a dominant allele, it is referred to as:

Answer 25

Recessive ## Footnote Recessive traits only appear when an individual has two copies of the recessive allele (homozygous recessive, aa).

Question 26

If a gene is present on one of the first 22 pairs of human chromosomes, it is said to be:

Answer 26

Autosomal ## Footnote Autosomal genes are located on chromosomes 1-22, while genes on the 23rd pair (X or Y chromosome) are sex-linked.

Question 27

Mendel’s Law that states alleles for different traits are distributed to sex cells independently is:

Answer 27

Independent Assortment ## Footnote Mendel’s Law of Independent Assortment states that genes for different traits separate independently during gamete formation, creating genetic diversity.

Question 28

What term describes the situation where multiple genes determine a single trait?

Answer 28

Polygenic Inheritance ## Footnote Polygenic inheritance involves multiple genes influencing a trait, such as height, skin color, or eye color.

Question 29

If both parents are heterozygous for a trait, what is the probability that an offspring will be homozygous dominant?

Answer 29

25% ## Footnote In a Punnett square (Aa × Aa), the offspring ratio is: * AA (homozygous dominant) - 25% * Aa (heterozygous) - 50% * aa (homozygous recessive) - 25%.

Question 30

In a dihybrid cross involving two heterozygous genes (AaBb × AaBb), what is the probability of producing an offspring that is homozygous dominant for both traits?

Answer 30

1/16 ## Footnote A dihybrid cross (AaBb × AaBb) produces offspring in a 9:3:3:1 ratio, where only 1 out of 16 (AABB) is homozygous dominant for both traits.

Question 31

Which of the following best describes a trait that is determined by more than two genes?

Answer 31

Polygenic Inheritance ## Footnote Traits like height and eye color result from multiple genes interacting, making them polygenic traits rather than controlled by a single gene.

Question 32

What inheritance pattern does the ABO blood group system demonstrate due to the presence of three different alleles?

Answer 32

Multiple Alleles ## Footnote The ABO blood system (IA, IB, i) follows multiple allele inheritance because there are more than two possible alleles for one gene.

Question 33

When an individual's phenotype is influenced by more than one pair of genes, this is known as:

Answer 33

Polygenic Inheritance ## Footnote Multiple gene pairs contribute to polygenic traits, resulting in continuous variation in characteristics like skin tone or intelligence.

Question 34

An organism's observable characteristics are determined by its:

Answer 34

Both genotype and environment ## Footnote Phenotype (observable traits) is determined by both genetic makeup (genotype) and environmental influences (e.g., nutrition affecting height).

Question 35

If an individual exhibits a blend of two parental traits, this is most likely a result of:

Answer 35

Incomplete Dominance ## Footnote In incomplete dominance, the heterozygous phenotype is a blend of both alleles (e.g., red and white flowers producing pink offspring).

Question 36

What bond forms between two monosaccharide units in a disaccharide?

Answer 36

Glycosidic bond ## Footnote A glycosidic bond forms between two monosaccharides during dehydration synthesis, linking them into a disaccharide (e.g., sucrose, maltose, lactose).

Question 37

Which carbohydrate is primarily stored in the liver and muscles for energy?

Answer 37

Glycogen ## Footnote Glycogen is the storage form of glucose in animals, found mainly in the liver and muscles, providing a quick energy source.

Question 38

What level of protein structure involves the sequence of amino acids in the polypeptide chain?

Answer 38

Primary ## Footnote Primary structure refers to the specific sequence of amino acids in a protein, determining its final shape and function.

Question 39

Which of the following is NOT a disaccharide?

Answer 39

Ribose ## Footnote Ribose is a monosaccharide, not a disaccharide. Disaccharides include sucrose, lactose, and maltose.

Question 40

Which carbohydrate is primarily a structural molecule in the cell walls of plants?

Answer 40

Cellulose ## Footnote Cellulose is a polysaccharide that forms the rigid cell walls of plants, providing structural support.

Question 41

Which level of protein structure is determined by the spatial arrangement of multiple polypeptide chains?

Answer 41

Quaternary ## Footnote Quaternary structure involves multiple polypeptide chains assembling to form a functional protein complex (e.g., hemoglobin).

Question 42

Lactose is composed of which two monosaccharides?

Answer 42

Glucose and galactose ## Footnote Lactose (milk sugar) is a disaccharide composed of glucose and galactose.

Question 43

The specific sequence of which molecules determines the function of a protein?

Answer 43

Amino acids ## Footnote The order of amino acids in a protein determines its folding and function.

Question 44

Which level of protein structure involves the alpha-helix and beta-pleated sheet formations?

Answer 44

Secondary ## Footnote The secondary structure of proteins consists of alpha-helices and beta-pleated sheets, formed by hydrogen bonding between amino acids.

Question 45

Which carbohydrate form is linear and unbranched?

Answer 45

Cellulose ## Footnote Cellulose is a linear, unbranched polysaccharide that provides structural support in plants.

Question 46

Which level of protein structure is determined by interactions between side chains of amino acids?

Answer 46

Tertiary ## Footnote Tertiary structure is formed by interactions between side chains (R groups) of amino acids, stabilizing the protein’s 3D shape.

Question 47

The molecule that provides quick energy for cells and is a product of photosynthesis is:

Answer 47

Glucose ## Footnote Glucose is the primary energy source for cells and is produced in photosynthesis.

Question 48

Which carbohydrate form provides plants with their rigid structure?

Answer 48

Cellulose ## Footnote Cellulose is a structural polysaccharide found in plant cell walls, making plants rigid and strong.

Question 49

Which protein aids in the coagulation of blood?

Answer 49

Fibrinogen ## Footnote Fibrinogen is a blood-clotting protein that helps form fibrin strands to stop bleeding.

Question 50

Which disease is non-infectious and cannot be spread from person to person?

Answer 50

Asthma ## Footnote Asthma is a chronic respiratory condition caused by environmental factors, genetics, or allergies. It is not caused by an infectious agent and cannot be spread.

Question 51

Which of the following is a single-celled eukaryotic organism?

Answer 51

Protozoans ## Footnote Protozoans are single-celled eukaryotic organisms that can move independently and may cause diseases like malaria and amoebic dysentery.

Question 52

Diseases like HIV/AIDS and influenza are contagious. What does 'contagious' mean in this context?

Answer 52

Easily spread from person to person ## Footnote Contagious diseases can spread easily between individuals through direct contact, airborne droplets, or bodily fluids.

Question 53

Which type of microscope would be most appropriate for viewing a live amoeba in a water sample?

Answer 53

Light microscope ## Footnote A light microscope is best for observing living specimens in liquid, such as an amoeba, as it does not require sample preparation that could kill the organism.

Question 54

Which micro-organism forms a part of the natural human gut flora and can be beneficial?

Answer 54

Bacteria ## Footnote Certain bacteria in the gut, such as Lactobacillus and Bifidobacterium, aid in digestion, vitamin production, and immune function.

Question 55

What is the primary method of transmission for a disease like rabies?

Answer 55

Through infected saliva ## Footnote Rabies is transmitted through the bite or saliva of an infected animal, introducing the virus into the bloodstream.

Question 56

What type of infectious agent is responsible for conditions like candidiasis?

Answer 56

Fungi ## Footnote Candidiasis is caused by Candida, a type of fungus that can overgrow and lead to infections in the mouth (thrush) and genitals (yeast infections).

Question 57

Which micro-organism is responsible for causing bacterial pneumonia?

Answer 57

Bacteria ## Footnote Bacterial pneumonia is most commonly caused by Streptococcus pneumoniae, which infects the lungs and causes respiratory distress.

Question 58

How do infectious diseases like the common cold primarily spread?

Answer 58

Direct contact ## Footnote The common cold is primarily spread through direct contact with infected individuals, contaminated surfaces, or respiratory droplets.

Question 59

Which micro-organism causes diseases by producing toxins?

Answer 59

Bacteria ## Footnote Some bacteria (e.g., Clostridium botulinum, Staphylococcus aureus) release toxins that cause illnesses like botulism and food poisoning.

Question 60

Which type of infectious agent is responsible for diseases like AIDS?

Answer 60

Viruses ## Footnote AIDS is caused by the Human Immunodeficiency Virus (HIV), which attacks the immune system and makes individuals vulnerable to infections.

Question 61

Which disease is non-infectious and results from an individual's own immune system attacking healthy cells?

Answer 61

Rheumatoid arthritis ## Footnote Rheumatoid arthritis is an autoimmune disorder, meaning the immune system mistakenly attacks the body’s own tissues, causing inflammation and joint damage.

Question 62

Which type of microscope provides a detailed, high-resolution view of small specimens but kills the sample in the process?

Answer 62

Transmission electron microscope ## Footnote Transmission electron microscopes (TEMs) provide high-resolution images of internal cellular structures, but require sample preparation that kills the specimen.

Question 63

Which step in the scientific method involves formulating a hypothesis based on previous knowledge or observations?

Answer 63

Deduction ## Footnote Deduction involves forming a hypothesis or theory based on prior observations or existing knowledge to explain the phenomena.

Question 64

In the scientific method, which step involves identifying the problem or question?

Answer 64

Introduction ## Footnote The introduction step of the scientific method involves identifying and stating the problem or research question that will be investigated.

Question 65

What kind of relationship exists when an increase in one variable leads to a decrease in another?

Answer 65

Negative correlation ## Footnote A negative correlation means that as one variable increases, the other decreases, demonstrating an inverse relationship.

Question 66

Which term describes a factor that is not the focus of an experiment but might affect its results?

Answer 66

Confounding variable ## Footnote A confounding variable is an external factor that can affect the dependent variable but isn't being tested directly in the experiment.

Question 67

What is the primary purpose of the deduction step in the scientific method?

Answer 67

Drawing conclusions from the data ## Footnote The deduction step involves drawing conclusions or forming generalized statements based on the data collected in the testing phase.

Question 68

In an experiment, the introduction primarily serves to:

Answer 68

Explain the background and purpose ## Footnote The introduction provides the background information, defines the research problem, and sets the purpose of the experiment.

Question 69

When two variables increase in tandem, they share what kind of relationship?

Answer 69

Positive correlation ## Footnote A positive correlation occurs when both variables increase together, showing a direct relationship.

Question 70

The primary reason to use a control group in an experiment is to:

Answer 70

Have a group to compare with the treatment group ## Footnote The control group serves as a baseline for comparison, allowing researchers to determine the effects of the experimental treatment.

Question 71

In a correlation between increased study hours and higher exam scores, which statement is accurate?

Answer 71

A relationship exists between study hours and exam scores, but it doesn't confirm causation. ## Footnote Correlation shows a relationship but does not establish causation, meaning the relationship may not imply that study hours directly cause better exam scores.

Question 72

In the observation step of the scientific method, a researcher is primarily:

Answer 72

Identifying patterns or phenomena ## Footnote Observation involves identifying and recording patterns or phenomena that will lead to the formulation of a hypothesis.

Question 73

What can you infer about the poles of two magnets that repel each other?

Answer 73

Both are north poles or both are south poles. ## Footnote Like poles repel each other, meaning that if two magnets repel, they must both have the same pole facing each other (either both north or both south). Opposite poles (north and south) attract.

Question 74

What might you predict about the population of prey if the number of predators decreases in a closed system?

Answer 74

It will increase. ## Footnote Predators help control prey populations. If predator numbers decrease, fewer prey are being consumed, leading to a population increase of the prey species.

Question 75

What kind of energy is at its maximum when a pendulum momentarily stops at the peak of its swing?

Answer 75

Potential energy. ## Footnote At the highest point of its swing, the pendulum has stopped moving and has no kinetic energy. All of its energy is stored as potential energy due to gravity.

Question 76

What might you predict about a person's bone health if their diet is deficient in Vitamin D?

Answer 76

Reduced bone density and increased risk of fractures. ## Footnote Vitamin D is essential for calcium absorption, which is crucial for maintaining strong bones. A deficiency leads to weaker bones and an increased risk of fractures.

Question 77

What will you observe about the roots of a plant that exhibits geotropism when placed horizontally?

Answer 77

Roots will grow downwards. ## Footnote Geotropism (gravitropism) is a plant’s growth response to gravity. Roots exhibit positive geotropism, meaning they grow towards gravity (downward), while stems show negative geotropism, growing against gravity (upward).