Biology MCQ Quiz - Objective Question with Answer for Biology - Download Free PDF

The correct answer is option 3.

Key Points

• The pulmonary vein is the only vein in the human body that carries oxygenated blood. Hence, option 3 is correct.
• It transports oxygen-rich blood from the lungs to the left atrium of the heart.
• This is an exception because veins usually carry deoxygenated blood back to the heart.

Additional Information

• Cystic vein: Drains blood from the gallbladder into the portal vein (deoxygenated).
• Cardiac vein: Carries deoxygenated blood from the heart muscles to the right atrium.
• Hepatic Portal Vein: Carries nutrient-rich but deoxygenated blood from the intestines to the liver. 

The correct answer is Tomato.

Concept:

• Photosynthetic pigments are found in the thylakoid membranes. 
• Chlorophyll a, chlorophyll b, carotenes, and xanthophylls are photosynthetic pigments found in higher plants. 
• Plant pigments are coloured substances produced by plants that are essential for photosynthesis growth, regulation, and development.

Explanation:

• Lycopene is a carotenoid pigment that is commonly found in red or pink fruits or vegetables. 
• It gives these foods their characteristic color and is also known for its potential health benefits as an antioxidant. 
• It is also used as a supplement that may have protective effects against prostate cancer and cardiovascular disease.
• Some examples of fruits and vegetables that are rich in lycopene include:
  • Tomatoes
  • Watermelon
  • Red carrots
  • Papaya
  • Pink guava

Thus, Lycopene pigment is found in tomato.

The correct answer is Melatonin.

• Melatonin hormone plays an important role in the regulation of 24-hour rhythms of the sleep-wake cycle.
• It is also involved in the pigmentation of the skin, menstrual cycle, and metabolism.
• It also controls the cardiac rhythms of our body.
• Its increased secretion promotes healthy sleeping.
• This hormone delays puberty and affects the menstrual cycle.

Key Points

• Prolactin is the hormone of the anterior pituitary which stimulates the production of milk and also develops the mammary gland.
• Progesterone maintains the pregnancy and is involved in female sexual characteristics development and cortisol response against stress and also stimulates the formation of RBC.
• Cortisol is called the "stress hormone" because of its connection to the stress response. Cortisol is one of the steroid hormones and is made in the adrenal glands.

The correct answer is "shaking hands".

Key Points

•  Human immunodeficiency virus is an epidemic that assaults the body's immune system.
•  If it is not treated, it can lead to AIDS which is acquired immunodeficiency syndrome.
•  HIV does not spread by:
  • Air or water
  • Mosquitoes, ticks or different insects.
  • Saliva, tears or sweat that isn't blended with the blood of someone with HIV.
  • Shaking hands, hugging, sharing toilets, sharing dishes, silverware, or drinking glasses.
  • Drinking fountains
  • Other sexual sports do not contain the alternative of frame fluids.

Additional Information

• Mode of transmission
•  HIV transmits by direct contact with certain body fluids from a person with HIV who has a detectable viral load. These fluids are:
  • Blood
  • Semen and pre-seminal fluid
  • Rectal fluids
  • Vaginal fluids
  • Breast milk
• For transmission, the HIV virus in these fluids must get into the bloodstream of an HIV-negative person through a mucous membrane or by direct contact.

The correct answer is Collenchyma.

• The permanent tissue that provides elasticity is called Collenchyma.

Key Points

• Collenchyma cells are long elongated cells with an irregular thick wall. They have thick walls which provide support and elasticity to the plant's part. 
• They provide structural support and flexibility to the growing stems. It acts as a supporting tissue in the stems of young plants. It provides mechanical support, elasticity, and tensile strength to the plant body.
• Elasticity is provided by collenchyma because of the presence of hydrated pectin in their cell walls.
• Collenchyma consists of narrow cells.

Additional Information

• Collenchyma mainly provides mechanical strength to the growing plant parts.
• Collenchyma generally occurs in the hypodermis of the dicot stem. It is absent in the roots and also occurs in petioles and pedicels.

The correct answer is Protein synthesis.

Key Points

• Ribosomes are membranous granular structures present in the cytoplasm.
• They were first observed under an electron microscope as dense particles by George Palade in the year 1953.
• Ribosomes are the site for ''protein synthesis'' so they are also called the ''protein factory'' of the cell.
• There are two types of ribosomes

1. Eukaryotic ribosomes - 80s - occurs in the cytoplasm of eukaryotic cell
2. Prokaryotic ribosomes - 70s - occur in the cytoplasm as well as are associated with the cell membrane of prokaryotic cell.

• The subunits of the ribosomes are:
  • 80s ribosomes - are made of 60s and 40s subunits.
  • 70s ribosomes - are made of 50s and 30s subunits.

Important Points

• Composition of the structure of ribosome:
• They are composed of ribonucleic acid (RNA) and proteins

• Photosynthesis: It is the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. In this process, plant the chlorophyll, carbon dioxide, water, sunlight, and release oxygen.
• Synthesis of Fatty acids occurs in the cytoplasm.

The correct answer is Bile juice, Pancreatic juice.

Key Points

• Bile juice, Pancreatic juice secreted by the organs plays an important role in the digestion of fats.
• Bile juice is secreted by the liver.
  • It does not contain any types of enzymes.
  • The bile juice helps to make the food alkaline and break down the fat molecules.
• Pancreatic juice is secreted by the pancreas.
  • It contains enzymes like amylase, trypsin, pancreatic lipase, nucleases and lipase.
  • Secretion of the Pancreatic juice is regulated by the hormones secretin and cholecystokinin.
• Lipase is the digestive enzyme of fat.
• Ptyalin is the digestive enzyme of the Saliva.
• Hydrochloric acid is produced naturally in the human stomach to help the digestion of food.

The correct answer is Whale.

Key Points

• Gills are respiratory organs found in most aquatic organisms.
• Gills can extract dissolved oxygen from water and excrete carbon dioxide.
• Gills can be found in Octopus, Squid, Clownfish, Tadpole, Prawn, etc.
• Lungs are the breathing organ of Whales.

Additional InformationRespiratory organs of different Animals:

Concept:

Photosynthesis: 

• The leaves have a green pigment called chlorophyll.
• It helps leaves to capture the energy of the sunlight.
• This energy is used to synthesise (prepare) food from carbon dioxide and water. Since the synthesis of food occurs in the presence of sunlight, it is called photosynthesis.

In the presence of sunlight Carbon dioxide + water → Carbohydrate + oxygen.

• Some plants, green algae, and cyanobacteria can perform photosynthesis.
• The process of photosynthesis is commonly written as

                   6CO2 + 6H2O + Sun-Light → C6H12O6 + 6O2

Plant cells have a cell wall to protect them and make them rigid structure.

Explanation:

1. Plants convert energy from sunlight into food stored as carbohydrate’s - Correct

2. Plants have chlorophyll. - Correct

3. Plant cells do not have cell walls. - Incorrect.

Additional Information

In the plant cells, there are different components and organelles for specific functions-

• Cell Wall – It is a rigid layer composed of cellulose. It is the outermost layer of the cell, below this cell membrane is present. The primary function of the cell wall is to protect and provide structural support to the cell.
• Cell Membrane – It is a semi-permeable membrane that helps in regulating and the substance for entry and exit inside and outside the cell.
• Nucleus – It is a vital part of the cell as it contains all the information or DNA of the cell and their heredity information for growth and cell division.
• Vacuole – Most of the part of the plant cell is occupied by the vacuole. It is surrounded by Tonoplast. The vital role of the vacuole is to provide support again the pressure of the cell wall.
• Golgi apparatus – They act as a transport system in the cell, as they transport various molecules to a different part of the cell.
• Ribosomes – They are the sites of protein synthesis, also termed as the protein factory of the cell.
• Mitochondrion – They break the complex molecules and produce energy and hence called the powerhouse of the cell.
• Lysosomes – They are termed suicidal bags as they hold the enzymes that are capable to digest the whole cell itself.

An earthworm is a tube-shaped, segmented worm found in the phylum Annelida. They are commonly found living in soil, feeding on live and dead organic matter.

The correct answer is Both chloroplast and mitochondria

Concept:

Theory of endosymbiosis:-

• Symbiotic relationship, where one organism lives inside the other, is known as endosymbiosis. 
• The theory proposed that mitochondria and chloroplasts evolved from engulfed prokaryotes.
• A large anaerobic bacteria engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host, gradually developing into a mitochondrion.
• It is believed that chloroplasts originated from a cyanobacterial endosymbiont.

Explanation:

Similarities between Prokaryotic cells, Mitochondria, and Chloroplast:

• Mitochondria and chloroplast are of the same size as prokaryotic cells.
• Mitochondria and prokaryotic cells both have their own circular DNA.
• The ribosome of bacteria, mitochondria, and chloroplasts have a 70S type of ribosome.
• Divides by binary fission.

• Vitamin K is a vitamin found in leafy green vegetables, broccoli, and Brussels sprouts.
• In the body, vitamin K plays a major role in blood clotting. So it is used to reverse the effects of “blood-thinning” medications when too much is given; to prevent clotting problems in newborns who don’t have enough vitamin K, and to treat bleeding caused by medications.

Tricks:

The correct answer is Cellulose.

• Plant cell walls are primarily made of cellulose.

Key Points

• Cellulose is the most abundant macromolecule on Earth.
  • Cellulose fibers are long, linear polymers of hundreds of glucose molecules.
  • These fibres aggregate into bundles of about 40, which are called microfibrils.

Additional Information

• Carbohydrates are the sugars, starches, and fibres found in fruits, grains, vegetables, and milk products.
  • A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H), and oxygen (O) atoms.
• Lipids are molecules that contain hydrocarbons and make up the building blocks of the structure and function of living cells.
  • A lipid is a biomolecule that is soluble in nonpolar solvents.
• A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid also known as fat molecules in water, as in blood plasma or other extracellular fluids.
  • It consists of a Triglyceride and Cholesterol centre, surrounded by a phospholipid outer shell, with the hydrophilic portions oriented outward towards the surrounding water and lipophilic portions oriented inward toward the lipid centre.

The correct answer is Collenchyma.

 Concept:

• Collenchyma is a specialized simple permanent tissue that provides support and flexibility to plants.
  • This tissue is made up of living cells having uneven thickenings of cellulose, pectin, and hemicellulose on the walls.
  • Cells possess chloroplast, then it is involved in manufacturing sugar and starch.
  • Provides tensile strength and flexibility to the plant body.

Explanation:

• Parenchyma- this tissue provides support to plants. It also stores food. So this option is not correct.

• Collenchyma- it allows easy bending of plant parts and provides flexibility. So the option is correct.
• Sclerenchyma- this tissue makes the plant hard and stiff. It is present in the husk of a coconut. So the option is not correct.

Additional Information

• Parenchyma is the most common and abundant tissue in plants which is made up of thin-walled living cells having a distinct nucleus.
  • The main function of parenchyma is to store and assimilate food. Hence, they are referred to as food storage tissues.
  • Serves as a packing tissue to fill the spaces between other tissues and maintain the shape and firmness of the plant.
  • Stores waste products of plants.
• Sclerenchyma is a lignified supportive tissue made up of thick-walled and lignified cells.
  • Provides mechanical strength to the plant.

Influenza disease is caused by a Virus.

Trick: Virus influence many Diseases