The World of Living - 2 - Free MCQ Practice Test with solutions, CTET Science

Human beings sweats to maintain body temperature. Evaporation of sweat on the body surface leads to cooling effect.

Human heart is divided into four chambers. Heart receives oxygenated blood into upper chamber called left atrium.

Lactobacillus is the microorganism present in curd. This bacterium converts milk into curd at 30 to 40oC.

White blood cells are part of the immune system and play a crucial role in defending the body against infections. They actively engage in combating and eliminating germs that may enter the body.

• Scion is the detached living part of the plant which is grafted to the stalk by the process of grafting.
• Grafting is a horticulture technique where the living detached portion of the plant is used to regenerate the growth.
• One plant is selected for its roots and this is called the stock or rootstock. The other plant is selected for its stems, leaves, flowers, or fruits and is called the scion.
• The joining of scion and stalk is known as inosculation. The technique is mostly used in the asexual mode of reproduction. 
  
  

Those plants whose seeds contain two cotyledons are called dicotyledonous plant. Gram is a dicotyledonous plant.

Heart rate increases during exercise and fever because our body doesn't get enough of oxygen that is required for proper functioning of the body.

Cellular respiration occurs primarily in the cells of living organisms. This process involves converting food into energy, which is essential for various cellular functions. Here are some key points:

• Cellular respiration takes place in the mitochondria, often referred to as the powerhouses of the cell.
• It involves the breakdown of glucose in the presence of oxygen to produce energy.
• This energy is stored in the form of ATP (adenosine triphosphate), which cells use for various activities.

Understanding this process is crucial for grasping how living organisms function and maintain their energy levels.

Transport of water and minerals  is through two kinds of elements of xylem tissue called xylem vessels and tracheid that water and minerals move from roots of a plant to its leaves.

During hibernation, an animal's body temperature, heart rate, breathing, and other metabolic activities slow down significantly in order to conserve energy. While resources are scarce, hibernation allows animals like bears, chipmunks, and bats to use their stored energy much more slowly.

In flowering plants, male gamete is formed inside Anther present at the top of Stamen.

Flowers are called bisexual if they bear both androecium and gynoecium.

• Reproductive parts include flowers, fruits and seeds whereas the vegetative parts of the plant are leaf, stem, roots and leaves. The chief function of the flowers is sexual reproduction. They achieve fertilization with the process of pollination.
• Flower is the reproductive part of an angiospermic plant containing male and female reproductive organs.

The ureter is a tubular structure which starts from the kidney and ends in the the urinary bladder .It's work is to carry urine formed in the kidney to the bladder for another temporary storage

In flowering plants, the ovary is the enlarged basal portion of the pistil, which is the female reproductive organ of a flower. The ovary contains ovules, which are structures that contain the female gametes or egg cells. After fertilization occurs, these ovules develop into seeds. The ovary itself undergoes further development and matures into a fruit, which protects the seeds and aids in their dispersal. So, the ovary plays a crucial role in the reproduction and propagation of flowering plants.

Animals such as elk, moose, mule deer, white-tailed deer, pronghorn, mountain goat, bighorn sheep, black bear,yak grey wolf, etc. are found in the mountain ecosystem.

The part of breathing during which oxygen rich air is taken in is called inhalation.

Platelets are tiny blood cells that help your body form clots to stop bleeding. If one of your blood vessels gets damaged, it sends out signals to the platelets. The platelets then rush to the site of damage and form a plug (clot) to fix the damage.

Asexual reproduction produces individuals that are genetically identical to the parent plant. It does not involve two parents, instead only a single parent is involved in this process. In asexual reproduction, the organism reproduces on its own without the help of other organisms. Seeds are formed as a result of the fusion of male and female gametes which occurs in sexual reproduction. In plants, vegetative reproduction is a type of asexual reproduction where an entire plant is obtained from the vegetative parts of a single parent.

Organisms that obtain their food from others are called Heterotrophs. Heterotrophs are organisms that cannot produce their own food and must rely on other organisms as a source of energy and nutrients. This includes animals, fungi, and some bacteria that feed on other organisms or organic matter. In contrast, autotrophs are organisms that can produce their own food, such as plants and algae, through photosynthesis or chemosynthesis.

The xylem and the phloem make up the vascular tissue of a plant and transports water, sugars, and other important substances around a plant. One xylem and one phloem are known as a 'vascular bundle' and most plants have multiple vascular bundles running the length of their leaves, stems, and roots.

In grasslands, because of the open lands, animals can move freely. Most grassland animals are able to run very fast, which allows them to escape hunting animals.

Yeast is used for the production of alcohol and wine by the process of fermentation.

The fusion of male and female gametes takes place during sexual reproduction. Fusion results to formation of zygote that is first cell of any living organism.

The process of transfer of larva into adults through drastic change in their body is called metamorphosis. Larva changes into totally different shape and size through metamorphosis.

Marine plants are primarily found in the:

• Sea: This is the most common habitat for marine plants, including various types of algae and seagrasses.
• Desert: Marine plants do not inhabit this environment.
• Jungle: While some plants thrive in jungles, they are not classified as marine.
• Mountain: This area is not suitable for marine plant life.

Thus, the primary habitat for marine plants is the sea.

External fertilization is the fertilization where the fertilization takes place outside the body while the internal fertilization is the process where the sperms fertilize the eggs inside the body. Fish undergoes external fertilization. The female releases unfertilized eggs into the water which is fertilized by the sperms of the male. In order to increase the chance of fertilization, the fishes release an enormous amount of eggs in the water.

In asexual reproduction only one parent is involved. The new organism is identical to parent. No gametes formation takes place in asexual reproduction.

Red blood cells (RBCs) are responsible for transport of oxygen to different parts of the body due to presence of haemoglobin in it.

During exhalation, i.e. releasing air during respiration, the ribs move downwards to reduce the volume of the thoracic cavity.
During exhalation, your diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles between the ribs also relax to reduce the space in the chest cavity. As they relax they position the rib cage downwards and inwards.