Sb3 Keywords biology Flashcards
1
Q
Asexual reproduction
A
Producing new organisms from one parent only. These organisms are genetically identical to the parent
2
Q
Clone
A
All the cells in a clone are genetically identical to each other and to the parent’s cells.
3
Q
Fertilisation
A
Fusing of a male gamete with a female gamete.
4
Q
Invertebrate
A
An animal without bones
5
Q
Mitosis
A
The process of diploid cells dividing to produce two diploid daughter cells that are genetically identical to the parent.
6
Q
Sexual reproduction
A
Reproduction that needs a male and a female
7
Q
Variation
A
Differences in the characteristics of organisms
8
Q
Vertebrae
A
Animals with a back bone
9
Q
Chromosome
A
A structure found in the nuclei of cells. Each chromosome contains one enormously long DNA molecule packed up with proteins.
10
Q
Daughter cell
A
A cell produced by another cell that has divided.
11
Q
Diploid
A
A cell or nucleus that has two sets of chromosomes. In humans, almost all cells except the sperm and egg cells are diploid.
12
Q
DNA
A
Deoxygenated
13
Q
Egg cell
A
The female gametes in humans
14
Q
Gamete
A
A haploid cell used in sexual reproduction
15
Q
Gene
A
Section of the long strand of DNA found in a chromosome, which often contains instructions for a protein.
16
Q
Genome
A
All the DNA in an organism. Each body cell contains a copy of the genome.
17
Q
Haploid
A
A cell or nucleus that has one set of chromosomes. Gametes are haploid.
18
Q
Meiosis
A
A form of cell division in which one parent cell produces four haploid daughter cells.
19
Q
Mitosis
A
A form of cell division in which one parent cell produces two diploid daughter cells.
20
Q
Polymer
A
A molecule made out of a chain of repeating similar units (called monomers).
21
Q
Replicates
A
When DNA replicates it makes a copy of itself
22
Q
Sperm cell
A
The male gamete in humans
23
Q
Zygote
A
Another term for fertilised egg
24
Q
Adenine
A
On of the bases found in dna. Also know as A
25
Base dna
Four substance that help make up DNA, often shown by the letters A, C, G and T. Pairs of bases form ‘links’ between two ‘spines’ formed of phosphate groups and a type of sugar.
26
Complementary base pair
Two DNA bases that fit into each other and link by hydrogen bonds. There are two types of complementary base pair: A linking with T, and C linking with G.
27
Cytosine
One of four bases found in dna. Also known as C
28
Double helix
Structure of dna
29
Guanine
One of four bases found in dna. Also know as G
30
Hydrogen bond
Weak force of attraction caused by differences in the electrical charge on different parts of different molecules.
31
Thymine
One of four bases found in dna. Also know as T
32
Hydrogen bond
Weak force of attraction caused by differences in the electrical charge on different parts of different molecules.
33
Hydrogen bond
Weak force of attraction caused by differences in the electrical charge on different parts of different molecules.
34
Codon
A set of three bases (a triplet) found in DNA and RNA. The genetic code is formed from patterns of codons.
35
Complementary
Means ‘fitting together’. Complementary bases in a DNA molecule fit together.
36
Genetic code
A set of rules defining how the base order in DNA or RNA is turned into a specific sequence of amino acids joined in a polypeptide chain.
37
Genetic code
A set of rules defining how the base order in DNA or RNA is turned into a specific sequence of amino acids joined in a polypeptide chain.
38
Messenger rna (mRNA)
A single strand of rna used in transcription
39
Nuclear pore
A small hole in the membrane of the nucleus
40
Ribonucleic acid
RNA
41
Ribosome
A protein that attaches to mRNA. It allows transfer RNA (tRNA) molecules to match up with the mRNA codons and also joins the amino acids together.
42
RNA
Abbreviation of ribonucleic acid. The molecule is made of phosphate groups and sugars (called ribose) linked together with one of four bases.
43
Template strand
The strand of a DNA molecule that RNA polymerase uses to make mRNA.
44
RNA polymerase
An enzyme the creates mRNA from DNA
45
Transcription
The process by which the genetic code in one strand of DNA molecules is used to make mRNA.
46
Translation
The process by which the genetic code in a molecule of mRNA is used to make a polypeptide.
47
Transfer rna (tRNA)
A molecule of rna that carries amino acids
48
Uracil
A base found in rna but not dna
49
Allele
Most genes come in different versions called alleles. So a gene for eye colour may have one version (allele) that can cause dark eyes, and another allele that can cause pale eyes.
50
Genetic disorder
A problem caused by genes
51
Mutation
A change to a gene caused by a mistake in copying the DNA base pairs during cell division, or by the effects of radiation or of certain chemicals.
52
Phenotype
The characteristics that a certain set of alleles display.
53
Dominant
Allele that will always affect the phenotype (as opposed to a recessive allele, whose effect will not be seen if a dominant allele is present).
54
Genetic diagram
Diagram showing how the alleles in two parents may form different combinations in the offspring when the parents reproduce.
55
Genetic variation
The alleles for a certain characteristic that are found in an organism. Written in a shorthand using letters to represent the alleles (with the dominant allele having a capital and being written first).
56
Heterozygous
When both the alleles in gene are the same in an organism
57
Homozygous
When both the alleles for a gene are the same in an organism.
58
Monohybrid inheritance
The study of how the alleles of just one gene are passed from parents to offspring.
59
Ratio
A relationship between two quantities, usually showing the number of times one value is bigger than the other. For example, if there are six red buttons and two blue buttons, the ratio of red to blue is 3 to 1, also written 3:1.
60
Recessive
Allele that will only affect the phenotype if the other allele is also recessive. It has no effect if the other allele is dominan
61
Family pedigree chart
A chart showing the phenotypes and sexes of several generations of the same family, to track how characteristics have been inherited.
62
Probability
The likelihood of an event happening. Can be shown as a fraction from 0 to 1, a decimal from 0 to 1 or as a percentage from 0% to 100%.
63
Punnet square
Diagram used to predict the different characteristics in the offspring of two organisms with known combinations of alleles. You can use the square to work out the probability (how likely it is) that offspring will inherit a certain feature.
64
Sex chromosome
Chromosome that determines the sex of an organism. In humans, males have one X sex chromosome and one Y sex chromosome, while females have two Xs
65
ABO blood group
Blood group system in humans which produces four phenotypes: blood groups A, B, AB and O
66
Carrier
An individual that has inherited a recessive allele but does not show the phenotype caused by that allele. For example, a woman who has one allele for a sex-linked genetic disorder and one ‘healthy’ allele will not suffer from the disorder but can pass it on to a son.
67
Codominant
Two alleles that both affect the phenotype. For example a person with the blood group alleles IA and IB has blood group AB.
68
Sex-linked genetic disorder
A disorder caused by genes that are inherited differently in males and females because they are carried on the sex chromosomes. An example is red–green colour blindness, which is more common in men than in women
69
Acquired characteristics
A characteristic that can change during life, due to a change in the environment. (See also environmental variation.
70
Continuous variation
Continuous data can take any value between two limits. Examples include length, mass, time. Continuous variation is when differences in a characteristic are continuous
71
Discontinuous variation
A values that can only have one of a set number of options are discontinuous. Examples include shoe sizes and blood groups. Discontinuous variation is when differences in a characteristic are discontinuous.
72
Environmental variation
Differences between organisms caused by environmental factors, such as amount of heat, light, damage. These differences are called acquired characteristics
73
Genetic variation
Differences between organisms caused by differences in the alleles they inherit from their parents, or differences in genes caused by mutation.
74
Mean
An average calculated by adding up the values of a set of measurements and dividing by the number of measurements in the set
75
Median
The middle value in a data set
76
Mode
Most common value in data set
77
Normal distribution
When many individuals have a middle value for a feature, with fewer individuals having greater or lesser values. This sort of data forms a bell shape on charts and graphs.
78
Range
The difference between the highest and lowest values in a set of data (usually ignoring any outliers or anomalous results).
