2. Life On Earth Flashcards Preview

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Flashcards in 2. Life On Earth Deck (42)
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1
Q

Abomasum

A

The fourth and final section of the stomach in ruminants, were food is digested by acid and enzymes.

2
Q

Absorption

A

The taking in of a substance, usually a liquid.

3
Q

Aerobic

A

Living or active in the presence of oxygen.

4
Q

Amino acids

A

Organic compounds which are the building blocks of proteins. There are about 20 essential amino acids in humans that we have to take in.

5
Q

Anaerobic

A

The absence of oxygen.

6
Q

Archaea

A

Archaea are procaryotic ‘primitive’ cells that are not bacteria and have an unusual chemistry. Many live in extreme environments like hot springs or acidic lakes.

7
Q

Asexual Reproduction

A

The production of a new organism without gametes. It can involve spores or simple division.

8
Q

Autotrophs

A

Organisms that make their own food from inorganic components such as plants.

9
Q

Bacteria

A

Unicellular procaryotic organisms usually between 0.5 and 5 micrometres. Bacteria have cell walls made of different biochemicals to those found in plants and archaea.

10
Q

Biochemicals

A

Chemicals found in or associated with living things.

11
Q

Robert Brown

A

The first scientist to describe the nucleus of a cell.

12
Q

Carnivore

A

An animal which eats other animals.

13
Q

Cell Division

A

The process by which cells form daughter cells. It consists if mitosis and cytokinesis.

14
Q

Cell Membrane

A

A layer that separates the cell from its environment and controls the passage of materials into and out of the cell.

15
Q

Cell Wall

A

A structure outside the cell membrane and occurs in plants and fungi. It provides support and contains cellulose, pectin and lignin.

16
Q

Chloride Ion

A

An atom with an extra electron which makes it a negatively charged particle - an electrolyte; it is found in cells and is important in cellular activity.

17
Q

Chlorophyll

A

The green pigment in plants associated with the capture of sunlight for use in photosynthesis.

18
Q

Chloroplast

A

A green organelle or plastid in plants responsible for photosynthesis.

19
Q

Chromosomes

A

Thread-like bodies that appear in cell division and are responsible for transmitting genetic information.

20
Q

Circulatory System

A

The organ system consisting of the heart, arteries, veins, capillaries and blood in vertebrates and is responsible for the transport of oxygen, nutrients and wastes around the body.

21
Q

Colonial Organisms

A

Organisms consisting of a loose aggregation of sllghtly specialised cells that re-aggregate if disturbed.

22
Q

Concentration

A

Concentration is the amount of a substance - often relative to the amount of solute in a solution - and can be expressed as a percentage or g/L and so on.

23
Q

Cuticle

A

Cuticle is the protective wax outer covering of a leaf or the flexible outer surface of some invertebrates made if chitin.

24
Q

Cyanobacteria

A

Cyanobacteria (one called blue-green algae) are procaryote cells that carry out photosynthesis and represent one of the most primitive groups of living things.

25
Q

Cytokinesis

A

Cytokinesis is the final stage of cell division involving the redistribution of the cytoplasm between daughter cells.

26
Q

Cytoplasm

A

The contents of the cell membrane excluding the nucleus. It includes the transparent liquid, cytosol and organelles. It is the site of most of the chemical activities that occur in the cell.

27
Q

Daughter Cells

A

Daughter cells are the products of cell division.

28
Q

Dermis

A

Dermis is a type of tissue that provides the external covering layer of plants. Also the layer below the epidermis in vertebrates.

29
Q

Differentiation

A

Differentiation refers to the changes that occur in development and result in a cell becoming specialised in structure and function.

30
Q

Diffusion

A

Diffusion is the movement of material (usually fluids) from places of high concentration to places of lower concentration until the solution is evenly mixed.

31
Q

Digestive Chemicals

A

Digestive chemicals are substances (enzymes) that break complex molecules into simpler ones.

32
Q

Diverticulum

A

Diverticulum is a specialised branch of the stomach in nectar feeders which stores nectar.

33
Q

DNA

A

DNA is deoxyribonucleic acid, the large organic molecule (nucleic acid) responsible for storing hereditary information in living things, and is found on chromosomes.

34
Q

Endoplasmic Reticulum

A

Endoplasmic reticulum is a double membrane that forms a convoluted network of tubes that connects the cell membrane to the nucleus.

35
Q

Epidermal Cells

A

Epidermal cells (plant) are cells that provide the outermost protective layer on plant structures such as leaves.

36
Q

Epithelial Tissue

A

Epithelial tissue makes up the surface of the body and organs. It serves the functions of protection and/or secretion, absorption and sensation.

37
Q

Eubacteria

A

Eubacteria (or bacteria) were once called ‘true bacteria’ and are distinguished on the basis of shape. They are widespread and some cause disease while others are essential for our well-being.

38
Q

Eucaryotic Cells

A

Eucaryotic cells are cells that contain a nucleus and organelles and genetic material borne on chromosomes.

39
Q

Exchange

A

To give up and receive or replace.

40
Q

Excretory System

A

Excretory system is the system of organs with the function of removing wastes from the organism.

41
Q

Freeze Fracture

A

A method for preparing specimens for the electron microscope involving rapid freezing followed by splitting. It is a useful method for investigating at the internal structure of membranes.

42
Q

Glucose

A

Glucose is a simple monosaccharide sugar, commonly produced by digestion of more complex carbohydrates (and other compounds) in animals, and is a product of photosynthesis in plants. It is the major reactant in respiration.