Test: Classification of Plants - Class 7 MCQ

The contractile vacuole in amoebas functions to collect and expel excess water from the cell. This process is crucial for maintaining osmotic balance within the organism and preventing bursting due to excess water intake.

The primary distinction between dicotyledons and monocotyledons lies in the number of cotyledons (seed leaves). Dicotyledons have two cotyledons, while monocotyledons have one, leading to differences in their seed structure and plant development.

Classifying living organisms allows scientists to study them systematically by grouping them based on shared traits and characteristics. This organization helps in understanding the relationships among different organisms and simplifies research efforts.

Fungi play a critical role in ecosystems by decomposing organic matter. They break down dead organisms and recycle nutrients back into the soil, which is essential for plant growth and ecosystem health.

The kingdom Animalia is characterized by organisms that are typically motile and can move from one place to another, unlike plants that are generally stationary. This mobility is often linked to their need to seek food and escape predators.

Fungi obtain nutrients through absorption. They secrete enzymes that break down complex organic matter into simpler substances, which are then absorbed through their cell walls, allowing them to feed on decaying material.

Organisms in the kingdom Fungi are primarily heterotrophic, meaning they absorb nutrients from organic matter. They play a vital role in ecosystems by decomposing dead materials and recycling nutrients.

Tuberculosis is a disease caused by the bacteria Mycobacterium tuberculosis. It primarily affects the lungs and is transmitted through airborne particles, highlighting the impact of bacteria on human health.

Gymnosperms are a type of plant that bear seeds but do not produce fruits; instead, their seeds are exposed and often found in cones. Common examples include pine and fir trees, which are adapted to various environmental conditions.

Phaeophyta, commonly known as brown algae, includes species that exhibit brown pigmentation due to the presence of pigments like fucoxanthin. This group includes important marine organisms such as kelp.

The kingdom Protista consists of unicellular organisms that have a well-formed nucleus. Examples include Amoeba and Paramecium. This classification highlights their complexity compared to prokaryotic organisms in the Monera kingdom, where the nucleus is not membrane-bound.

An amoeba moves primarily by extending pseudopodia, which are temporary, finger-like extensions of its cytoplasm. This method of movement is known as amoeboid movement, allowing the amoeba to navigate through its aquatic environment.

Lactobacillus bacteria play a significant role in fermenting sugars, particularly in the production of yogurt. They convert lactose into lactic acid, which gives yogurt its tangy flavor and preserves it by creating an acidic environment.

The kingdom Monera was introduced in Robert Whittaker's five-kingdom classification system. It includes prokaryotic organisms such as bacteria, which were previously grouped with plants and animals, highlighting the need for a distinct classification for these organisms.

Antibiotics are medicines that destroy disease-causing germs in the body. They are derived from certain bacteria and are crucial in treating infections in both humans and animals, showcasing the beneficial applications of bacteria in medicine.