Few terms used in Biology Topics
Important Data Related to Biology Topics
Human RBC - 7 – 8 µm.
Unicellular eukaryote - 5 – 100 µm in size.
Human RBC and lymphocytes - 7-8 µm (smallest).
Human nerve cell - 90 cm long (largest).
Largest acellular plant Acetabularia - 10 cm long and animal Amoeba-1 mm.
Largest prokaryote Spirulina - 13 – 15 µm.
Fibres of ramie - 55 cm long and hemp fibres - 100 cm long.
Smallest prokaryotic cell Mycoplasma hominis (PPLO) - 0.1 – 0.3 µm in size.
The cell of a multicellular eukaryote - is 1 – 1000 µm in size.
Ostrich egg (Largest cell) is 15-20 × 13.5-15 cm in size. An Ostrich egg is not considered a true cell as it stores a large amount of reserve food. Viruses do not have a cellular structure.
Biology Dictionary
Artificial Classification: Classification based on one or at the most few characters.
Ascus: A cell in which nuclei fuse and go through meiosis after which the protoplast divides and forms meiospores.
Archegonium: Female gametangium or egg-bearing organ in which the egg is protected by a jacket of sterile cells.
Basidiospores: Type of meiospore borne by basidia in the basidiomycetes.
Carotenes: A reddish-orange plastid pigment.
Carotenoids: A class of fat-soluble compounds that includes carotenes, Xanthophyll.
Heterogamy: Reproduction involving two types of gametes.
Heterospory: The condition of producing two kinds of spores [mega and micro]
Heterothallic: Incapable of self-fertilization.
Meiosis: A type of nuclear division in which four cells are produced each with half the chromosome number of the original cell.
Population: A group of inbreeding organisms.
Triploblastic: Mesoderm is also present along with ectoderm and endoderm in the embryo.
Haemocyanin: Blue-coloured respiratory pigment.
Sexual Dimorphism: Sexes separate.
Hibernation: Winter Sleep
Aestivation: Summer sleep
Artificial Classification: Classification based on one or at the most few characters.
Ascus: A cell in which nuclei fuse and go through meiosis after which the protoplast divides and forms meiospores.
Archegonium: Female gametangium or egg-bearing organ in which the egg is protected by a jacket of sterile cells.
Basidiospores: Type of meiospore borne by basidia in the basidiomycetes.
Carotenes: A reddish-orange plastid pigment.
Carotenoids: A class of fat-soluble compounds that includes carotenes, Xanthophyll.
Heterogamy: Reproduction involving two types of gametes.
Heterospory: The condition of producing two kinds of spores [mega and micro]
Heterothallic: Incapable of self-fertilization.
Meiosis: A type of nuclear division in which four cells are produced each with half the chromosome number of the original cell.
Population: A group of inbreeding organisms.
Triploblastic: Mesoderm is also present along with ectoderm and endoderm in the embryo.
Haemocyanin: Blue-coloured respiratory pigment.
Sexual Dimorphism: Sexes separate.
Hibernation: Winter Sleep
Aestivation: Summer sleep
Frequently Asked Questions
The cell is called the structural and functional unit of life because
(a) all living organisms are made up of cells.
(b) all the functions taking place in the body of an organism are performed by cells.
The shape depends on functional adaptations and partly on the surface tension, the viscosity of protoplasm, the mechanical action exerted by adjoining cells and the rigidity of the cell membrane.
Bones have a hard and non–pliable ground substance rich in calcium and collagen fibres. The bone cells called osteocytes are present in spaces called lacunae It provides the structural frame to the body, and support and protect the softer tissue and organs. Long bones of limbs/legs bear body weight. Bones attached to themselves and muscles bring about body movements. Bone Marrow produces blood cells.