Animal Physiology MCQ: Definition and Explanations

Ans: B. Oxytocin

Explanation: The pituitary gland is found at the base of the brain just below the hypothalamus. It has two components, viz. anterior pituitary and posterior pituitary. In the posterior pituitary, many neurons of the hypothalamus end. The ends are axonal terminals of neurons that originate in the hypothalamus. They produce two peptide hormones called vasopressin and oxytocin. These relocate down into the posterior pituitary through axonal endings as well as stored in secretory vesicles for release. The oxytocin hormone launched from the posterior pituitary contracts the smooth muscle cells in the uterus throughout parturition in mammals.

Ans: B. Protein

Explanation: Collagen is a fibrous structural healthy protein existing in the extracellular matrix as well as the connective tissue of animals. It is the single most extreme healthy protein in the animal kingdom. Collagen is crucial for skin flexibility. In fibrous cells such as the skin, tendons, and ligaments, it is discovered as extended fibrils.

Ans: A. A type of Bone cell

Explanation: Osteocytes are the largest living bone cell, comprising 90-95% of cells in bone tissue. It inhabits a small chamber called a lacuna, which is contained in the calcified matrix of bone. Osteocytes create when osteoblasts end up being buried in the mineral matrix of bone and develop distinct features.

Ans: A. Glutamine

Explanation: A neurotransmitter is an endogenous chemical that makes neurotransmission possible. They transmit signals throughout the target neuron/muscle/gland cell. Chemically, they are of 2 kinds: Small Molecule transmitters that are swiftly acting and also trigger the most acute response of the nervous system by diffusing throughout the synaptic cleft. Examples are Acetylcholine, glutamate (glutamic acid), glycine, gamma-aminobutyric acid (GABA), epinephrine, norepinephrine, dopamine, serotonin and histamine. Glycine and GABA are the most common repressive neurotransmitters.

Neuropeptides cause even more extended action in nerves, such as long-term changes in the number and size of synapses. Example: Enkephalins, endorphins etc. Considering that glutamine is not found in synapses. It is not a neurotransmitter.

Ans: C. Ovum

Explanation: The biggest cell in the Human Body is the ovum. The ovum is, also called the egg cell, is the reproductive cell in the woman's body. Ovum is 20 times bigger than the sperm cells and has a diameter of about 0.1 mm.

Ans: A. prostaglandins and thromboxane

Explanation: Paracrine hormones are hormones that operate near the site of production and secretion. They vary from endocrine hormones in that they are created in a single place rather than being carried throughout the body via the circulatory system. Paracrine hormones are created at numerous locations throughout the body and function in their immediate area rather than being transferred to their site of action. Prostaglandins and thromboxane are two examples.

Ans: B. 2123/2123

Explanation: The dental formula depicts how the teeth in the upper and lower rows are arranged. Adult human beings' dental formula is 2123/2123. One row contains two incisors, one canine, two premolars, and three molars. The adult human being has 32 teeth in total.

Ans: C. 1, 2 and 3

Explanation: In Human females, the ovary is a paired organ. It is found in the pelvic cavity on both sides of the uterus. Ligaments hold it together. The ovary is connected to the uterus by the ovarian ligament. The suspensory ligament joins the ovary to the body wall, and the Broad ligament connects the sides of the uterus to the pelvic wall and floor and covers the ovary. As a result, all three ligaments are attached to the ovary.

Ans: D. inhibiting the motor protein dynein

Explanation: Gossypol is a polyphenolic pigment derived from the cotton plant. In China, it was used as a male oral contraceptive. Because of its extreme toxicity, its use has been discontinued. It immobilized sperms by blocking the motor protein dynein. Dynein is an ATPase present in sperm flagella and is related to microtubules. It hydrolyzes ATP, which provides energy for sperm movement. When dynein ATPase is blocked, sperm becomes immobile and is unable to swim to the egg for fertilization. This has the effect of being a contraceptive.

Ans: C. Haemocyanin

Explanation: Snails, spiders, and octopi, unlike mammals, do not use hemoglobin to transport oxygen but rather rely on a similar chemical known as hemocyanin. Hemocyanin absorbs all colors except blue, which reflects blue blood.