General Science Questions (MCQs) for Competitive Examinations

Notes:
In menstrual cycle 19-21 days stands for the fertilizing period also called danger period. After ovulation on 14th day chances of contraption are at their highest with well developed endometrium for implantation. This is the time in the menstrual cycle when progesterone should be at its peak for the month and when estrogen should be at the height of its luteal plateau.

Notes:
The leaves arise in the regions of the plant known as the plant nodes and are therefore the point of attachment of the leaves. The region of the plant between two nodes is known as the internode. The angle between the upper surface of the leaf and the stem from which it arises is known as the axil.

Notes:
Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than the ventral portion. This is because the shark’s vertebral column extends into the dorsal portion, providing a greater surface area for muscle attachment.

Notes:
Hydra is radially symmetrical, that is, the parts of its body are arranged in a circle around a central median axis passing through the mouth. Hydra reproduces by asexual and sexual methods. Asexual reproduction takes place either by budding or by fission.

Notes:
Oviparous is a zoological term that refers to animals that lay eggs which then hatch externally. Oviparous animals may fertilize their eggs either externally or internally. Frogs are oviparous since they lay eggs, which then develop outside of the mother. Ovoviviparous animals are relatively uncommon, sharks are most well-known.

Notes:
The kidneys perform many crucial functions, including: maintaining overall fluid balance. regulating and filtering minerals from blood. filtering waste materials from food, medications, and toxic substances. The renal corpuscle of each kidney nephron has two parts – they are the Glomerulus, which is a network of small blood vessels called capillaries, and the Bowman’s Capsule (also known as the Glomerular Capsule), which is the double-walled epithelial cup within which the glomerulus is contained. A nephron is the basic structural and functional unit of the kidney. They are the microscopic structure composed of a renal corpuscle and a renal tubule. The word nephron is derived from the Greek word – nephros, meaning kidney. There are about millions of nephrons in each human kidney.

Notes:
Advancing glaciers distort the shape of the rings of trees because melting ice of glaciers not only increase water level in ocean but also contribute to the weather changes of a place that affect formation of annual rings.

Notes:
The blood sugar concentration or blood glucose level is the amount of glucose (sugar) present in the blood of a human or animal. The body naturally tightly regulates blood glucose levels as a part of metabolic homeostasis. The mean normal blood glucose level in humans is about 4 mM (4 m mol/L or 72 mg/dL, i.e. milligrams/decilitre); however, this level fluctuates throughout the day.

Notes:
Red rot disease is caused by the fungus Glomerella tucumanensis. An older name,Colletotrichum falcatum, is still preferred by some pathologists. Red rot occurs in various parts of the sugar cane plant but it is usually considered a stalk and a seed-piece disease. Its symptoms are highly variable depending upon the susceptibility of the sugarcane variety and the environment.

Notes:
The vascular tissue system consists of the complex tissues, xylem and phloem, which constitute discrete conducting strands called vascular bundles. Gymnosperms are the vascular plants where seeds are not enclosed within an ovary (opposite to an angiosperm or flowering plants where seeds are enclosed by mature ovaries or fruits). Collateral vascular bundle is the most common type of vascular bundle in the stems and leaves of angiosperms and gymnosperms. Here xylem and phloem remain side by side arranged on the same radius.