33 reviewed questions with answers and explanations.
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The process in which complex substances are broken down into simpler ones is referred to as
B: catabolism
Catabolism breaks larger molecules into smaller ones and often releases usable energy. Anabolism builds more complex molecules; metabolism includes both kinds of reaction.
AI-reviewed · source checkedThe organelles present in cells that are actively respiring and photosynthesizing are
D: mitochondria and chloroplast
Mitochondria support aerobic cellular respiration, while chloroplasts carry out photosynthesis. A photosynthetic plant cell can use both organelles because photosynthesis does not replace its need for respiration.
AI-reviewed · source checkedWhich listed animal is the usual intermediate host of Taenia solium?
D: pig
Pigs are the usual intermediate hosts for Taenia solium, the pork tapeworm. Larval cysts can occur in pig tissues; adult worms live in the human intestine after infected pork is eaten.
AI-reviewed · source checkedThe structure labelled II in the organism is the
The organism is found in soils rich in
The plants that grow in deserts or very dry areas are referred to as
D: xerophytes
Xerophytes are plants adapted to dry environments. Their adaptations may include reduced leaves, water storage or physiological mechanisms that limit water loss; different species use different combinations.
AI-reviewed · source checkedThe structural adaptation of desert plants for water conservation is
C: spiny leaves
Reducing leaves to spines decreases the surface area available for water loss. Many desert plants combine this with other adaptations, such as water-storing tissues or specialised stomatal behaviour.
AI-reviewed · source checkedThe long, sharp talons of a bird of prey are primarily adapted for
D: grasping prey
Long, sharp talons allow predatory birds to seize and hold prey. The hooked beak commonly performs much of the tearing, while the feet secure the captured animal.
AI-reviewed · source checkedLong-distance transport of substances between different parts of a plant is broadly termed
B: translocation
Translocation is the transport of substances from one part of a plant to another, especially sugars through phloem. Water and mineral ions also move through the vascular system, chiefly in xylem.
AI-reviewed · source checkedWhich salivary enzyme begins the digestion of starch?
D: ptyalin
Ptyalin is salivary alpha-amylase, which begins starch digestion in the mouth. Pepsin acts in the stomach, while salivary amylase targets carbohydrate rather than fats.
AI-reviewed · source checkedPlants that have special devices for trapping and digesting insects are
A: carnivorous
Carnivorous plants capture and digest small animals to supplement mineral nutrition, particularly in nutrient-poor habitats. They generally still photosynthesise rather than depending on prey for all organic food.
AI-reviewed · source checkedThe process that transfers energy from cellular fuels into ATP in plants is
D: respiration
Cellular respiration transfers energy from organic fuels into ATP that cells can use. Plants respire as well as photosynthesise; the two processes perform different roles in energy conversion.
AI-reviewed · source checkedWhich listed feature is consistent with fungi obtaining organic food instead of photosynthesising?
B: lack chlorophyll
Fungi lack chlorophyll and obtain organic carbon by absorbing materials from other organisms or their remains. Their heterotrophy is defined by this dependence on organic food, not by the shape of their bodies.
AI-reviewed · source checkedAn example of a parasitic protozoan is
B: Plasmodium
Plasmodium species are parasitic protists with life cycles involving a vertebrate host and a mosquito. Several species cause human malaria, unlike the usual free-living examples in the other choices.
AI-reviewed · source checkedWhich option lists the heart and all three major classes of blood vessels?
A: heart, arteries, capillaries and veins
The vertebrate circulation includes a heart and vessels organised as arteries, capillaries and veins. Arteries carry blood away from the heart, capillaries permit exchange and veins return blood.
AI-reviewed · source checkedWhich blood component consists of cell fragments that aggregate to form an initial plug at a damaged vessel?
D: Platelets
Platelets adhere at damaged vessels and aggregate to form an initial plug. They also support coagulation reactions, while soluble clotting factors in plasma contribute to fibrin formation.
AI-reviewed · source checkedWhich of the following forms about 55% of the volume of the blood in man?
C: plasma
Plasma is the fluid portion of blood and typically accounts for about55% of its volume. The remaining formed elements are mostly red blood cells, with much smaller contributions from white cells and platelets.
AI-reviewed · source checkedThe part of the mammalian skin involved in excretion is the
A: sweat glands
Sweat glands release water, salts and small quantities of nitrogenous substances onto the skin. Sweating is chiefly important for thermoregulation but also removes these substances from the body.
AI-reviewed · source checkedA common nitrogenous excretory product of terrestrial insects is
B: Uric acid
Many terrestrial insects excrete nitrogen chiefly as uric acid or urates. These poorly soluble products can be eliminated with relatively little water, which helps conserve water on land.
AI-reviewed · source checkedThe main structure in vertebrates that supports and protects the body is the
A: skeleton
The vertebrate endoskeleton supports the body and protects organs, such as the brain within the skull. Muscles act on the skeleton to produce movement, while ligaments connect bones at joints.
AI-reviewed · source checkedThe transfer of pollen grains from an anther to a stigma is
C: pollination
Pollination is the transfer of pollen from an anther to a stigma in flowering plants. Fertilisation occurs later, when gametes fuse following pollen germination and pollen-tube growth.
AI-reviewed · source checkedThe male reproductive organ of a flower is the
B: stamen
A stamen is the pollen-producing male reproductive structure of a flower, typically consisting of an anther and filament. A carpel contains the female reproductive structures.
AI-reviewed · source checkedThe gland that is found just below the hypothalamus is the
C: pituitary
The pituitary lies beneath the hypothalamus and is connected to it by the infundibulum. Their close anatomical relationship supports coordination of several endocrine pathways.
AI-reviewed · source checkedThe sensory cell that responds to dim light is referred to as the
C: rod
Rod photoreceptors respond effectively at low light levels and support dim-light vision. Cones provide colour and high-acuity vision under brighter conditions; lens and iris are not photoreceptor cells.
AI-reviewed · source checkedIn a typical nonpregnant reproductive-age female, the principal source of circulating oestrogens is the
A: ovaries
In a typical nonpregnant reproductive-age female, the ovaries are the principal source of circulating oestrogens. Smaller amounts can arise in other tissues, so synthesis is not exclusive to the ovaries.
AI-reviewed · source checkedClouding of the eye’s lens is called
C: cataract
A cataract is clouding of the eye’s lens, which can scatter or block light and reduce clear vision. It is different from glaucoma, which involves damage to the optic nerve.
AI-reviewed · source checkedEarth’s rigid outer rocky layer is the
D: lithosphere
The lithosphere is Earth’s rigid outer rocky layer. The atmosphere is the gaseous envelope, the hydrosphere includes water and the biosphere encompasses living systems.
AI-reviewed · source checkedWhich disease is caused by Treponema pallidum?
D: Syphilis
Treponema pallidum is the bacterium that causes syphilis. Gonorrhoea, leprosy and tuberculosis are caused by different bacterial species, despite also being infectious diseases.
AI-reviewed · source checkedConsidering only ABO compatibility for red-cell transfusion, which group is called the universal recipient?
D: AB
In the simplified ABO red-cell compatibility model, an AB recipient lacks anti-A and anti-B antibodies and can receive red cells of any ABO group. Actual transfusions still require other compatibility checks.
AI-reviewed · source checkedThe clumping together of red blood cells is
A: agglutination
Agglutination is the clumping of cells, such as red blood cells linked by antibodies reacting with their surface antigens. It differs from fusion, in which cell membranes merge.
AI-reviewed · source checkedDormancy that helps some animals survive hot, very dry periods is called
D: aestivation
Aestivation is a period of reduced activity or dormancy that can help some animals survive hot or dry conditions. Reduced metabolism and activity can lower resource needs during unfavourable periods.
AI-reviewed · source checkedOne water-conserving adaptation in Opuntia is the reduction of
C: leaves to spines
In Opuntia, leaves are greatly reduced and spines help limit the surface associated with water loss. The flattened green stems perform much of the photosynthesis and may store water.
AI-reviewed · source checkedWhich of the following structure is adapted for feeding in a bird of prey?
A: Hooked beak and sharp claws
A hooked beak can tear food, while sharp talons seize and hold prey. This combination is characteristic of many predatory birds and suits a diet of captured animals.
AI-reviewed · source checked