Answer: A) Rainfall Explanation: Savannas are home to a wide diversity of animals. Many animals of the savanna migrate throughout the year, searching for food and water. Many of the droughts are seasonal and hit one area before another, so animals are constantly following the rains.   Hence, Rain fall is what often governs animal migration on savannas.

Answer: A) Oxytocin Explanation: Oxytocin is a mamallian hormone and also acts as neuro transmitter in the brain.

Answer: A) 40.36 Explanation: Given, mean of 100 observations is 40 => Total of 100 observations = 40 x 100 = 4000 84 is misread as 48 => Difference = 84 - 48 = 36 => Now, new total of 100 observations = 4000 + 36 = 4036 Correct Mean = 4036/100 = 40.36

Answer: B) 320 ml Explanation: Here total parts of milk and water in the solution is 6+2 = 8 parts. 1part = 640/8 = 80   old mixture contains 6parts of milk and 2 parts of water(6:2).   To get new mixture containing half milk and half water, add 4parts of water to the old mixture then 6:(2+4) to make the ratio same. i.e, 4 x 80 = 320 ml.

Answer: A) Veins Explanation: Veins carries Blood back from the body parts to the Heart.   We know that The circulatory system of our body is a loop. The Heart is the pump, the arteries and their smaller branches (arterioles) carry oxygen rich blood all through your body and the veins and their smaller branches (venules) carry oxygen depleted blood and waste products back.

Answer: B) 1961 Explanation:

Answer: B) FALSE Explanation: Hemopoiesis begins in the red bone marrow, with hemopoietic stem cells that differentiate into myeloid and lymphoid lineages.   Myeloid stem cells give rise to all the other formed elements, including the erythrocytes; megakaryocytes that produce platelets; and a myeloblast lineage that gives rise to monocytes and three forms of granular leukocytes: neutrophils, eosinophils, and basophils.

Polarity ::  The polarity of a molecule defines its other physical properties such as melting point, boiling point, surface tension, vapor pressure etc... Simply, polarity occurs when the electron distribution in a molecule is asymmetric. This results in a net dipole moment in the molecule. One end of the molecule is charged negative while the other gets a positive charge.   The polarization of a molecule greatly depends on the shape of the molecule. A diatomic molecule like HF mentioned above has no issue of shape. The net dipole moment is only due to the uneven distribution of electrons between the two atoms. However, when there are more than two atoms involved in making a bond, there are many complexities.   The water molecule is of bent shape. Therefore, when the two pair of electrons shared by oxygen with two hydrogen atoms is pulled towards oxygen, the net dipole moment results in the direction of the oxygen atom. There is no other force to cancel out the resultant dipole moment. Hence, the water molecule is highly polar.   Ammonia molecule is of a pyramid shape and the electronegative N atom pulls the electrons towards itself. The three N-H bonds are not in the same plane; hence the dipole moments created do not get canceled out. This makes ammonia a polar molecule.   However, the dipole moments sometimes get canceled due to the shape of the molecules, making the molecule non-polar. Carbon dioxide is such a molecule.