Vocabulary Test Answers PDF

Amoeba - Protoctists that live in pond water and resemble animal cells. Cell - The basic building block of all living organisms. Cell membrane - A partially permeable barrier that surrounds the cell. Cell wall - An outer, structural layer that surrounds some cells. In plant cells, it is made of...

Amoeba - Protoctists that live in pond water and resemble animal cells. Cell - The basic building block of all living organisms. Cell membrane - A partially permeable barrier that surrounds the cell. Cell wall - An outer, structural layer that surrounds some cells. In plant cells, it is made of cellulose. In fungi, it is made of chitin. Chlorella - A protoctist that has features similar to plant cells e.g. chloroplasts. Chloroplast - An organelle which is the site of photosynthesis. DNA - A double-stranded polymer wound to form a double helix. It carries the genetic code. Plasmids - Loops of DNA found in the cytoplasm of prokaryotic cells. Plasmodium - Pathogenic protoctists that cause malaria. Pneumococcus - A spherical, pathogenic bacterium that causes pneumonia. Prokaryotic cell - A type of cell found in bacteria that does not contain a nucleus. Protoctists - Microscopic single-celled organisms. Cell differentiation - The process by which a cell becomes specialised to its function. Cell membrane - A partially permeable barrier that surrounds the cell. Cell wall - An outer, structural layer that surrounds some cells. In plant cells, it is made of cellulose. In fungi, it is made of chitin. Chloroplast - An organelle which is the site of photosynthesis. Cytoplasm - A jelly-like substance that contains all the organelles of the cell, dissolved nutrients and salts. Mitochondria - An organelle which is the site of respiration Active site - Part of the enzyme that is complementary to the shape of the substrate. The shape of the active site may change if the enzyme is exposed to high temperatures or extremes of pH. Amino acids - Small molecules from which proteins are assembled. Enzymes - Biological catalysts that increase the rate of reactions in living organisms. Glycogen - A large carbohydrate made from many glucose molecules joined together. It serves as an energy store in animals. Lipids - A group of large molecules that are made from long fatty acid chains and glycerol. Lipids include fats and oils. Proteins - Large molecules made up of amino acids. Starch - A large carbohydrate molecule made up of many glucose molecules. It contains the elements carbon, oxygen and hydrogen. It is an energy storage molecule in plants. Active transport - The movement of substances from a more dilute solution to a more concentrated solution (against the concentration gradient) with the use of energy from respiration. Concentration gradient - The difference in concentration between two areas. Diffusion - The spreading out of particles in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration (down the concentration gradient). Osmosis - The diffusion of water molecules from a more dilute solution to a more concentrated solution across a partially permeable membrane. Amniotic fluid - The fluid that surrounds and protects the embryo in the uterus. Asexual reproduction - A form of reproduction involving a single parent. It creates genetically identical offspring. Cuttings - The simplest method of cloning plants. A branch is cut from a parent plant and replanted in compost after removing the lower leaves. Embryo - An unborn organism in an early stage of development. Fertilisation - The fusion of the nucleus of male and female gametes. It restores the full chromosome number. *Follicle-Stimulating Hormone (FSH) - A hormone produced by the pituitary gland that stimulates the growth of follicles in the ovary and the secretion of oestrogen. Gametes - Sex cells (sperm and egg cells) with half the usual number of chromosomes. *Luteinising Hormone (LH) - A hormone secreted by the pituitary gland that initiates ovulation (the release of an egg from the ovary). Menstrual cycle - The monthly cycle in women that involves the development of the uterus lining, ovulation, maintenance of the uterus lining and its shedding. Oestrogen - The main female reproductive hormone released by the ovaries that causes the growth and repair of the uterus lining. Oestrogen is also responsible for the development of secondary sexual characteristics in females. Placenta - A temporary organ attached to the lining of the uterus during pregnancy that provides nutrients to the developing embryo. Pollination - The transfer of pollen grains (either by the wind or insects) from the male part of a plant to a female part, enabling fertilisation. Progesterone - A hormone produced in the ovaries and placenta that maintains the uterus lining Primary consumers - Herbivores that consume producers at trophic level 2 of a food chain. Producers - Photosynthetic organisms (e.g. green plant or alga) at the start of the food chain that provide biomass for all living things. Pyramid of biomass - A table of the dry mass of living material at each trophic level of a food chain. This forms the shape of a pyramid. Pyramid of numbers - A diagram showing the numbers of organisms at each trophic level. Quadrat - A square grid of known area used in sampling to determine the abundance and distribution of organisms in an ecosystem. Secondary consumers - Carnivores that consume herbivores at trophic level 3 of a food chain. Tertiary consumers - Carnivores that consume other carnivores at trophic levels 4 and above of a food chain. Trophic level - The position of an organism in a food chain. Only around 10% of the energy is transferred from one level to the next.