IB Biology Exam Prep

Explanation
The nucleus controls all life activities in a cell. It contains the genetic material, DNA, which carries the instructions for the cell's functions and development. The nucleus regulates the synthesis of proteins and coordinates cell division. It also controls the activities of other organelles within the cell, such as the mitochondria and endoplasmic reticulum. Without a nucleus, a cell would not be able to carry out essential processes and would not be able to function properly.

Explanation
Chromosome is the correct answer because it contains DNA, which is the genetic material of an organism. Chromosomes are found in the nucleus of a cell and are responsible for carrying and transmitting genetic information. They are made up of DNA molecules that are tightly coiled and condensed. Chromosomes play a crucial role in inheritance and determining the traits and characteristics of an organism.

Explanation
The correct answer is "Cell". A cell is the smallest unit of life that can exist independently and perform all necessary functions of life. It is the basic building block of all living organisms, from single-celled organisms like bacteria to complex multicellular organisms like plants and animals. Cells have various structures and organelles that enable them to carry out essential processes such as metabolism, growth, reproduction, and response to stimuli. Without cells, life as we know it would not be possible.

Explanation
The correct answer is flagella. Euglena is a single-celled organism that moves by using whip-like structures called flagella. These flagella are located at the front end of the organism and help it to propel itself through water. The flagella are flexible and can move in a wave-like motion, allowing the euglena to move forward. The other options, cilia, pellicle, and sarcolemma, are not the locomotive structures of euglena.

Explanation
Taxonomy is the field that is concerned with the naming and classification of organisms. It involves categorizing organisms into different groups based on their characteristics and evolutionary relationships. Taxonomists use various methods and principles to organize and classify organisms, such as morphology, genetics, and behavior. This helps in understanding the diversity of life on Earth and allows scientists to study and compare different species more effectively.

Explanation
An autotroph is an organism that can produce its own food using energy from the sun or inorganic substances. Cocoyam plants are autotrophs because they can perform photosynthesis and convert sunlight into energy to produce their own food. Monkeys, lizards, and viruses are not autotrophs as they rely on external sources for their nutrition.

Explanation
Robert Hooke is the odd one out in terms of evolution because he is not primarily known for his contributions to the theory of evolution. Carl Linnaeus, Jean-Baptiste Lamarck, and Charles Darwin are all renowned for their work in the field of evolutionary biology. Linnaeus developed the system of binomial nomenclature, which is still used to classify and name species. Lamarck proposed the theory of inheritance of acquired characteristics, which was an early attempt to explain evolution. Darwin, of course, is famous for his theory of natural selection, which revolutionized our understanding of how species evolve over time. In contrast, Hooke was a polymath who made significant contributions to various scientific fields, but his work was not directly related to evolution.

Explanation
Homeostasis is the mechanism that ensures the maintenance of a constant internal environment in an organism. It involves various physiological processes that regulate body temperature, pH levels, blood pressure, and other factors within a narrow range. This balance is crucial for the proper functioning of cells and organs. Genetics, catabolism, and taxism do not directly contribute to maintaining a constant internal environment and are not as comprehensive as homeostasis in regulating the body's internal conditions.

Explanation
The lowest classification of living organisms is species. Species is the most specific level of classification, representing a group of organisms that can interbreed and produce fertile offspring. It is below the levels of genus, order, and phylum, which are broader classifications. Genus represents a group of closely related species, order represents a group of related genera, and phylum represents a group of related orders. Therefore, species is the correct answer as it represents the smallest and most specific classification level.

Explanation
The term "evolution" was introduced in the year 1809.