Ques:Q: Lymphatic capillaries are interlaced with the arterioles and venules of which system? Read this paragraph and choose the correct option from the provided answers: Figure 21.3 Lymphatic Capillaries Lymphatic capillaries are interlaced with the arterioles and venules of the cardiovascular system. Collagen fibers anchor a lymphatic capillary in the tissue (inset). Interstitial fluid slips through spaces between the overlapping endothelial cells that compose the lymphatic capillary. Choices: - skeletal systems - circulatory system - atmospheric system - cardiovascular system A:

Ans:cardiovascular system
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Ques:Q: What fills the epidermal cells that make up fingernails and toenails? Read this paragraph and choose the correct option from the provided answers: Fingernails and toenails consist of specialized epidermal cells that are filled with keratin . The keratin makes them tough and hard, which is important for the functions they serve. Fingernails prevent injury by forming protective plates over the ends of the fingers. They also enhance sensation by acting as a counterforce to the sensitive fingertips when objects are handled. Nails are similar to claws in other animals. They cover the tips of fingers and toes. Fingernails and toenails both grow from nail beds. As the nail grows, more cells are added at the nail bed. Older cells get pushed away from the nail bed and the nail grows longer. There are no nerve endings in the nail. Otherwise cutting your nails would hurt a lot!. Choices: - cellulose - chromatin - amino acids - keratin A:

Ans:keratin
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Ques:Q: The nervous system is characterized by electrical signals that are sent from one area to another. whether those areas are close or very far apart, the signal must travel along this? Read this paragraph and choose the correct option from the provided answers: 12.4 The Action Potential The nervous system is characterized by electrical signals that are sent from one area to another. Whether those areas are close or very far apart, the signal must travel along an axon. The basis of the electrical signal is the controlled distribution of ions across the membrane. Transmembrane ion channels regulate when ions can move in or out of the cell, so that a precise signal is generated. This signal is the action potential which has a very characteristic shape based on voltage changes across the membrane in a given time period. The membrane is normally at rest with established Na+ and K+ concentrations on either side. A stimulus will start the depolarization of the membrane, and voltage-gated channels will result in further depolarization followed by repolarization of the membrane. A slight overshoot of hyperpolarization marks the end of the action potential. While an action potential is in progress, another cannot be generated under the same conditions. While the voltage-gated Na+ channel is inactivated, absolutely no action potentials can be generated. Once that channel has returned to its resting state, a new action potential is possible, but it must be started by a relatively stronger stimulus to overcome the K + leaving the cell. The action potential travels down the axon as voltage-gated ion channels are opened by the spreading depolarization. In unmyelinated axons, this happens in a continuous fashion because there are voltage-gated channels throughout the membrane. In myelinated axons, propagation is described as saltatory because voltage-gated channels are only found at the nodes of Ranvier and the electrical events seem to "jump" from one node to the next. Saltatory conduction is faster than continuous conduction, meaning that myelinated axons propagate their signals faster. The diameter of the axon also makes a difference as ions diffusing within the cell have less resistance in a wider space. Choices: - axial - hairs - tendons - axon A:

Ans:axon
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Ques:Q: Natural methods of asexual reproduction, such as cuttings or budding, include strategies that plants have developed to perform what? Read this paragraph and choose the correct option from the provided answers: Natural Methods of Asexual Reproduction Natural methods of asexual reproduction include strategies that plants have developed to self-propagate. Many plantslike ginger, onion, gladioli, and dahliacontinue to grow from buds that are present on the surface of the stem. In some plants, such as the sweet potato, adventitious roots or runners can give rise to new plants Figure 32.25. In Bryophyllum and kalanchoe, the leaves have small buds on their margins. When these are detached from the plant, they grow into independent plants; or, they may start growing into independent plants if the leaf touches the soil. Some plants can be propagated through cuttings alone. Choices: - multi-propagation - mono-propagation - iso-propagation - self-propagation A:

Ans:
self-propagation
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