Homologous structures are such structures that do not show exact similarity in their appearance and function but are linked with their common ancestor. On the other hand, analogous structures are such structures that are similar in their function and appearance but do not have any links between their ancestors. The arms of humans, legs of dogs, are the common examples of homologous structure, where they must have diverged and evolved as different beings. The wing of insects, birds, bats and … [Read more...]

The onset of the first menstrual period in the female adolescent is the menarche, while the termination or end of the menstrual cycle in the females is known as menopause. These are the two significant physical and biological milestone in the female's life. The studies on these events reveal that partially genetic and partially non-genetic factors (environmental factors, lifestyle, etc.) influence the age at which menarche and menopause in females. Although there are various medical issues … [Read more...]

Dendrite refers to the 'Trees' in Greek, so these are the branched small extension of the nerve cell. Axon refers to the 'axis' in Greek, so axon is the long slender like protrusion of the neuron or nerve cell. Secondly, dendrite receives messages or information or electrochemical impulses from the external environment or other neurons, so they work as the input for the neuron.  The role of the axon is to send messages or any information or electrochemical impulses to the external environment … [Read more...]

Actin is the collective molecules of protein from which thin bands are formed. On the other hand, Myosin is the group of protein by which thick bands are formed. Actin and Myosin are responsible for various types of cellular movements, and the most striking one is the muscle contraction, that provides the best-model to understand the role of actin and myosin. Now, to know the function of actin-myosin, it is necessary to gather bit information about muscles contraction. The cellular and … [Read more...]

The chromosomes, apart from the sex chromosomes, are known as autosomes of an organism. The number of chromosomes varies from one organism to others. In humans, there is a total of 46 chromosomes or in pair of 23. Out of these, 2 are sex chromosome (XX or XY), and 44 are autosomes. Mice have in all 40 chromosomes, out of which 38 are autosomes, and 2 are sex chromosomes. Abnormalities in the chromosomes (autosomes or sex chromosomes) results in the retardation in growth of an organism or … [Read more...]

The word 'anatomy' means 'structure', while 'physiology' refers to 'function'. We can elaborate by saying that anatomy is the detailed study of different body parts, their organization, and their interrelationship, but how these body parts and organs play their specific role in a coordinated manner is termed as physiology. An understanding of these terms is not only beneficial to health professionals and their career; instead, it helps us know about your own body and its wellness. Familiarity … [Read more...]

Rods and Cones are the photoreceptors, useful in providing vision to the eyes. Rods provide vision during dim light or night also known as scotopic vision, whereas cones provide vision during day time or at bright light also known as photopic vision. Secondly, rods do not support the colour vision, but cones are capable of colour vision, with high spatial acuity — the level of the light where both the types of work, is called a mesopic vision. Eyes are one of the primary sense organs found … [Read more...]

Oestrogen or estrogen is the female steroid hormone known for the development of the female reproductive system, while progesterone is also another type of female steroid hormone known for releasing corpus luteum and supports the pregnancy. These are the types of steroids hormones and are categorized under two category which are corticosteroids and sex steroids. Among which the mineralocorticoids and glucocorticoids are the are the types corticosteroids, while oestrogen or estrogen, … [Read more...]

The state of inactivity and a low metabolic process performed by the animals during the winters is known as Hibernation. It is also known as winter sleep. On the contrary, when animals take rest in shady and moist place during summer, it is called Aestivation or Estivation. Aestivation is also known as summer sleep. The importance of these sleep is mainly related to the conservation of energy of one's body, survival during the extremes temperature, scarcity of food and water, etc. These sleep … [Read more...]

Birds, insects, reptiles, amphibians, and fish falls under the category of oviparous, as they lay eggs and give rise to more of their kind, in order to increase their generation. While mammals like humans, cats, dogs, lions, tigers, etc are said as the viviparous, as they directly give birth to the young ones. Fertilization is the union of two nuclei, one is of paternal origin and the other is from the maternal origin which finally fuses to form an embryo. There are different patterns of … [Read more...]