List of practice Questions

There is no mixing of oxygenated and deoxygenated blood in the human heart. Valves are present in the heart which allows the movement of blood in one direction only.
Thermoplastics become hard on heating and soft on cooling. Thermoplastics are cross-linked polymers which are soluble in many organic solvents.
Tracheae, primary, secondary and tertiary bronchi are supported by incomplete cartilaginous rings. These rings of cartilage make the wall non-collapsible.
Turner's syndrome is caused due to absence of any one of the $X$ and $Y$ sex chromosome. Such individuals show masculine as well as feminine development.
The stroma lamellae have both $PS I$ and $PS II$. The grana lamellae lack $PS II$ as well as $NADP $reductase enzyme.
The trichomes in the shoot system are usually multicellular. The trichomes help in preventing water loss due to evaporation.
There is hepatic portal system in frogs It is venous connection between liver and intestine in frog
The resting membrane of the neuron exhibits polarity of charges The outer surface of the axonal membrane possesses a negative charge while its inner surface becomes positively charged
The shape of the uterus is like an inverted pear. The inner glandular layer that lines the uterine cavity is called as myometrium.
The quasifluid nature of lipid enables lateral movement of proteins within the overall bilayer This ability to move within the membrane is called fluidity and is important for cell growth
: The radius of curvature of a mirror is double of the focal length. : A concave mirror of focal length $f$ in air is used in a medium of refractive index $2$. Then the focal length of mirror in medium becomes $2f$.
The primary $CO_{2}$ acceptor in $C_{4}$ pathway is $3$-carbon molecule phosphoenol pyruvate $(PEP)$. The enzyme responsible for this fixation is $PEP$ carboxylase or $PEP$case.
The process of pairing of the chromosomes is called synapsis. : Synapsis occurs during leptotene stage.
The proton gradient is broken down due to the movement of protons across the membrane to stroma through the transmembrane channel of the $F_{0}$ of the $ATP$ase. The breakdown of proton gradient leads to release of energy.
The outermost covering of a dicotyledonous seed is the seed coat. The seed coat has two layers-outer testa and inner hilum.
The pink coloured flowers appear in $F_2$ generation of plant . This is observed due epistatic suppression of white colour alleles in one of parental flowers by red colour alleles.
The placentation in which the placenta forms a ridge along the ventral suture of ovary and ovules are borne on this ridge forming two rows is called parietal placentation. The marginal placentation has ovules developed on the inner wall of the ovary or on peripheral part.
The position-time graph of a body moving uniformly in a straight line is parallel to position axis. The position-time graph in a non-uniform motion gives constant velocity at all instants of time.
The normal boiling point of water is $100 \,^{\circ}C$ and standard boiling point of water is $99.6 \,^{\circ}C$. The temperature at which vapour pressure of liquid is equal to the external pressure is called boiling temperature at that pressure.
The monomer of neoprene is $1, 3$-butadiene. Neoprene is highly inflammable.
The motion of a ceiling fan is rotational only. The motion of a rigid body which is pivoted or fixed in some way is rotation.
The motion of a particle under the central force is always confined to a plane. Angular momentum is always conserved in the motion under a central force.
The method of development of embryo sac from a single functional megaspore is termed as monosporic development. In monosporic (Polygonum) type of embryo sac development, usually the megaspore which is situated towards micropylar end remains functional.
The middle lamella is a layer made up of calcium pectate It holds the different neighbouring cells together
The middle piece is called as power house, of the sperm. The numerous mitochondria coiling around axial filament produce energy for the movement of the tail.