C190 Introduction to Biology Practice Questions - Set 1 - Part 2

Correct Answer: Incomplete dominance

In incomplete dominance, neither allele is dominant, resulting in a blended phenotype. Codominance involves both alleles being fully expressed, and epistasis is when one gene affects the expression of another.

Correct Answer: Movement against a concentration gradient

Active transport requires energy to move substances against their concentration gradient, unlike passive transport, which moves substances along the gradient without energy.

Correct Answer: Cell wall

The cell wall provides structural support to plant cells. The cell membrane controls the entry and exit of substances, while mitochondria generate energy, and the cytoplasm is where chemical reactions occur.

Correct Answer: Nitrogenous base

The nitrogenous base (adenine, thymine, cytosine, guanine) determines the identity of a nucleotide in DNA, while the sugar and phosphate groups remain constant across nucleotides.

Correct Answer: Photosynthesis

Photosynthesis uses light energy to convert carbon dioxide into glucose in plants. Cellular respiration breaks down sugars, glycolysis is the first step in respiration, and fermentation is anaerobic.

Correct Answer: Fix carbon dioxide into sugars

The Calvin cycle is responsible for fixing carbon dioxide into glucose during the light-independent reactions of photosynthesis. The light-dependent reactions capture light energy and produce ATP and NADPH.

Correct Answer: Asexual reproduction

Asexual reproduction produces genetically identical offspring through processes like binary fission or mitosis. Sexual reproduction results in genetic diversity through the combination of parental genes.

Correct Answer: Proteins

Enzymes are proteins that act as catalysts to speed up biochemical reactions in cells. Carbohydrates store energy, lipids provide long-term energy storage, and nucleic acids store genetic information.

Correct Answer: Anaphase I

In Anaphase I, homologous chromosomes are separated and pulled to opposite poles. Anaphase II separates sister chromatids during the second division of meiosis.

Correct Answer: Carbon

Carbon is the key element present in all organic compounds, forming the backbone of molecules like carbohydrates, proteins, lipids, and nucleic acids.

Correct Answer: The nuclear envelope breaks down and chromosomes condense

Prophase is the first stage of mitosis, where chromosomes condense and the nuclear envelope breaks down. Chromosomes align in metaphase, and sister chromatids are separated in anaphase.

Correct Answer: Carbohydrates

Carbohydrates, such as glucose, are the primary source of energy for most organisms. Proteins and lipids serve other functions like structure and long-term energy storage, while nucleic acids store genetic information.

Correct Answer: Diffusion

Diffusion is the movement of molecules from a higher concentration to a lower concentration, while osmosis refers to the diffusion of water. Active transport requires energy to move substances against the gradient.

Correct Answer: 3:1 phenotypic ratio

A monohybrid cross between two heterozygous individuals results in a 3:1 phenotypic ratio, with three showing the dominant trait and one showing the recessive trait. The 1:2:1 genotypic ratio refers to the genetic makeup of the offspring.

Correct Answer: Smooth Endoplasmic Reticulum

The smooth ER is involved in lipid synthesis and detoxification, while the rough ER is involved in protein synthesis. The Golgi apparatus modifies proteins, and ribosomes synthesize proteins.

Correct Answer: S phase

The S phase (synthesis phase) is when DNA replication occurs, preparing the cell for division. G1 and G2 are phases of growth, while M phase refers to mitosis.

Correct Answer: Eukaryotic cells contain membrane-bound organelles, prokaryotic cells do not

Eukaryotic cells have membrane-bound organelles like the nucleus, while prokaryotic cells do not. Prokaryotic cells are generally smaller and simpler in structure compared to eukaryotic cells.

Correct Answer: Electron Transport Chain

The electron transport chain generates the most ATP during cellular respiration, producing around 34 ATP molecules. Glycolysis and the Krebs cycle produce fewer ATP, and fermentation occurs in anaerobic conditions.

Correct Answer: Oxygen

The light-dependent reactions of photosynthesis produce oxygen as a byproduct, along with ATP and NADPH. Glucose is produced in the Calvin cycle, which is part of the light-independent reactions.

Correct Answer: Law of Segregation

The Law of Segregation ensures that during meiosis, homologous chromosomes separate, and each gamete receives only one allele for each gene. Independent assortment refers to the random distribution of alleles for different genes.