C190 Introduction to Biology Practice Questions - Set 3 - Part 1

Correct Answer: B) The maintenance of a stable internal environment

Homeostasis refers to an organism's ability to maintain stable internal conditions, such as body temperature and pH balance, despite changes in the external environment.

Correct Answer: C) Cell membrane

The cell membrane regulates the movement of substances into and out of the cell, maintaining the internal environment by being selectively permeable.

Correct Answer: B) Covalent bond

A covalent bond involves the sharing of electrons between atoms, while ionic bonds result from electron transfer, and hydrogen bonds are weak attractions between molecules.

Correct Answer: C) Grass

Biotic factors are living components of an ecosystem, such as plants, animals, and microorganisms. Grass is a living organism, whereas temperature, water, and soil are abiotic factors.

Correct Answer: B) Independent assortment

Independent assortment is the random distribution of homologous chromosomes to daughter cells during meiosis, increasing genetic variation.

Correct Answer: C) Mitochondria

Mitochondria are known as the "powerhouse" of the cell because they produce most of the ATP through cellular respiration.

Correct Answer: C) Lipids

Lipids, primarily phospholipids, form the bilayer of cell membranes, which separates the cell's internal environment from the external environment.

Correct Answer: A) Prophase

During prophase, the chromatin condenses into visible chromosomes, and the nuclear envelope begins to break down, allowing the chromosomes to be seen.

Correct Answer: B) Smooth endoplasmic reticulum

The smooth endoplasmic reticulum (ER) is involved in lipid synthesis and detoxification, while the rough ER is associated with protein synthesis due to its ribosomes.

Correct Answer: B) Genotype

The genotype refers to the genetic makeup of an organism, including the alleles it carries. Phenotype refers to the observable traits, and the genome is the entire set of genetic information.

Correct Answer: A) Glycolysis

Glycolysis is the first step in cellular respiration and occurs in the cytoplasm, breaking down glucose into pyruvate without the need for oxygen.

Correct Answer: C) Lipids

Lipids, such as fats and oils, are used for long-term energy storage in organisms, while carbohydrates provide short-term energy, and proteins and nucleic acids have other roles.

Correct Answer: B) Fertilization

Fertilization is the process by which male and female gametes combine to form a zygote, restoring the diploid number of chromosomes in the offspring.

Correct Answer: B) Codominance

In codominance, both alleles are equally expressed in the phenotype, as seen in cases like blood type AB, where both A and B alleles are expressed.

Correct Answer: C) Molecule

The molecule is the smallest level of biological organization, forming the building blocks of cells, which are the basic units of life.

Correct Answer: C) Active transport

Active transport requires energy (usually ATP) to move molecules against their concentration gradient, whereas simple diffusion, facilitated diffusion, and osmosis do not require energy.

Correct Answer: C) Photosynthesis

Photosynthesis is the process by which plants convert carbon dioxide and water into glucose and oxygen, using light energy captured by chlorophyll.

Correct Answer: B) Phenotype

The phenotype refers to the physical and observable traits of an organism, while the genotype refers to the genetic makeup.

Correct Answer: B) Proteins

Proteins, specifically enzymes, are responsible for catalyzing chemical reactions in cells. They speed up reactions without being consumed in the process.

Correct Answer: B) Oxygen

Oxygen is the final electron acceptor in the electron transport chain, combining with electrons and protons to form water.