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Biology answers to 194 questions

Previously, enzymes were thought to all be made of proteins, or proteinous in nature, however, it has been shown that not all enzymes are actually proteinous in nature. Enzymes are more accurately defined as biological catalysts that act on chemical…
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Genetic variation is the term used to describe differences in the DNA sequences of people. These differences can either be enhanced or reduced, based on specific factors. One factor that is most likely to decrease genetic variation is stabilizing selection.…
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All living things have their own lifecycle, depending on various contributing factors. The life span of an unfertilized egg is about 24 hours (a day). Prior to this time, an egg is released by the ovary every month and is…
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The nucleosome is the simplest structural unit of DNA packing, and the core is made up of proteins. The nucleosome core is made up of 8 different histone proteins, arranged in different patterns, around which Aa DNA segment is wrapped…
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The cardiac cycle is made up of 4 different stages through which blood flows to and from the heart. Each stage is characterized by movements of the tissues of the heart either in the opening, filling, closing, or emptying the…
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Depending on the location or type, each human cell has a specific number of chromosomes. Generally, humans are known to have a diploid number of chromosomes (46), except the gametes (23 chromosomes). All somatic cells are strictly diploid, and so…
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Mammals are distinct animals that possess backbones, a constantly warm internal temperature, hairs, or furs on their skins, have 4 chambered hearts, and feed their young with milk. These characteristics however are not all entirely unique to mammals, as other…
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While it is commonly believed that the more complex an organism, the more complex the arrangement or organization of internal organs, earthworms are different. Though not as complex as humans, an earthworm has five different hearts. The hearts, however, referred…
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The cells of living organisms are made up of large molecules that are responsible for their overall structure and functioning. These large molecules are referred to as biological molecules or macromolecules, and each macromolecule is made up of its own…
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The centromere refers to the dense region in a DNA sequence in the chromosome, usually found either in the middle or near the middle of a chromosome. It is the region in mitosis, where the microtubule spindles connect through the…
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Answer: B. Vitamin C. Explanation: vitamins in our diet are classified into two groups: fat soluble vitamins (A, D, E, and K), and water soluble vitamins (B and C). Fat soluble vitamins dissolve in fat and are transferred for storage.…
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Answer: b. Genomic library. Explanation: A genomic library is a combination of cloned fragments of DNA, which serve as representatives for the entirety of the genome of a particular entity. In simpler terms, the genomic library serves as a collection…
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Answer: C. Cornea. Explanation: In the human eye, most refraction occurs when light passes through the cornea, as the cornea is the first medium through which light travels before it travels further into the eye. The cornea is the curved,…
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Irrespective of its state, blood is referred to as a connective tissue because it has qualities of connective tissues. For example, blood comprises cells, a non-fluid matrix (plasma), and fibers -three basic properties of connective tissues. Also, like connective tissues,…
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Axons are nerve fibers that are long and slender and are projected from a nerve cell, and function as conductors of impulses outwards from the cell body to a synapse. Dendrites are slender projections of nerve cells that function as…
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Muscle cells have a large number of mitochondria cells. The reason for this is that muscle cells demand a very high amount of energy to support the movement, exercise, and other metabolic processes. To meet up this demand, the mitochondria…
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Answer: C. Proterozoic, Palaeozoic, Mesozoic, Cenozoic Explanation: The Proterozoic era refers to the first era when there was a buildup of oxygen in the atmosphere, as well as the emergence of multicellular organisms at the most primitive level. Only after…
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Answer: A. The S-phase. Explanation: In the S-phase, the replication of DNA occurs, and this is carried out by the DNA polymerase. During the G-phase, the cell produces new proteins as it continues to grow. At the end of this…
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Answer: Nil Explanation: The skeleton is the body's support system of bones, and it has six primary functions in the body. One of the most important functions of the skeletal system is to manufacture blood cells in the bone marrow.…
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Answer: C. Alleles. Explanation: Alleles are one or more alternative forms of a particular genetic material that are usually present in a specific position on a chromosome. Hybrids are organisms formed from the cross-breeding of organisms within or outside the…
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Typically, there are two types: type A and type B. An individual is born with either, both, or none of the blood groups. If the man has Blood types A or O on either chromosome and the woman has Blood…
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A wetland is an area of land that has most of its area covered by water, some of the areas being soggy and/ or marshy. In wetlands, like in other ecosystems, there is a well-defined food chain, which comprises the…
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Although both the anteater and the aardvark look alike and have the same diet, there are several differences between the two different species of animals. For example, while anteaters belong to the order "Tubulidentata", aardvarks belong to the "Pilosa" order.…
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Coniferous trees have needles in place of leaves, while deciduous trees have broad leaves. Coniferous trees retain the color of their needles when it's Fall, while the leaves of deciduous trees change color during the Fall. Coniferous trees have no…
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Starfish are a group of echinoderms that feed on corals, clams, oysters, sponges, mussels, small barnacles, and other small aquatic organisms. Typically, starfish eat almost anything that attaches itself to a rock, or that doesn't move away fast enough. If…
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Answer: B. Sporophyte. In seedless plants, a fertilized egg will develop into a sporophyte (i.e. the diploid phase of the life cycle of a plant), which produces spores by meiosis to give rise to gametophytes, which then produce gametes by…
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Answer: B. Vascular tissue and seeds. Gymnosperms and angiosperms both have vascular tissues that exist to function specifically in the transportation and distribution of water, organic compounds, minerals, etc. throughout the plant. Whether it's hidden within the fruit (like in…
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Answer: A. Growth hormone The growth hormone is directly responsible for regulating the growth and metabolism of carbohydrates, lipids, and proteins. The growth hormone is a non-tropic hormone, in that it directly stimulates target cells to produce an effect. In…
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Answer: A. Primary level. The primary level is bonded by peptide bonds, which form polypeptide chains. The primary level of the protein shows the specific sequence followed by amino acids in both polypeptide and disulfide bonding location. The primary level…
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Answer: 2. Dopamine. Dopamine is a neurotransmitter that is connected with bodily functions like movement, learning, attention, and mood and is the major substance that facilitates the feeling of pleasure and the thrill that comes with receiving rewards. The distribution…
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