Definitions Flashcards
Interspecific variation
Differences between different species
Random sampling
Something a population to eliminate bias
E.g. Grid square and coordinates
Intraspecific variation
Differences between members of the same species
Standard deviation
Indicates variation around a mean value
A normal distribution curve
A bell shaped curve
Graph is symmetrical
Nucleotide
A section of DNA made up of sugar, phosphate and a base
Complementary
A-T
C-G
Gene
A section of DNA that codes for making a polypeptide
Triplet code
Three bases code for an amino acid
Chromosome
I threadlike structures are made up of proteins and DNA
Passes hereditary information
Homologous chromosome
Two chromosomes determining the same characteristic
One from mother, one from father
Allele
One of the different forms of a gene
Meiosis
Cell division that produces 4 haploid, genetically different, daughter cells
Locus
The position of a gene on chromosome
Independent segregation
Homologous pairs randomly separate during meiosis 1, into separate cells
Crossing over
The process with chromatids break and rejoin with their homologous chromosomes to exchange alleles
Selective breeding
Breeding individuals with desired characteristics together and selecting the offspring show the desired characteristics
The founder effect
A few individuals colonise a new region, carrying a small amount of alleles of the larger population
Genetic bottleneck
A drop in the allele variety due to a large decrease in population size
Affinity
How easily oxygen is taken up
Associating loading
The process by which haemoglobin combines with oxygen in the lungs
Disassociating unloading
The process by which haemoglobin releases oxygen in the tissues
Starch
The storage molecule in plants
Coiled
Insoluble
Can be hydrolysed to form alpha glucose
Glycogen
Storage molecule and animals
Short chains
Easily hydrolysed into Alpha glucose
Cellulose
Parallel chains of beta glucose joined by hydrogen bonds
Forms microfibrils for strength
Chloroplasts
Organelle in plant cells containing grana, thylakoids and stroma
Photosynthesis occurs here
Semiconservative replication
The way DNA makes exact copies of itself by winding the double helix
Each chain acts as a template for the new strands
Mitosis
Cell division with two daughter cells are produced and have the same number of chromosomes as the parent
Haploid cells
Cells with half the number of chromosomes
Diploid cells
Cells with a full set of chromosomes
Cell cycle
So is regular cycle of division followed by periods of growth Interphase Prophase Metaphase Anaphase Telophase
Cell differentiation
Cells become specialised in the structure to suit their roles
Allele switch on and off
Tissue
The collection of similar cells that form a specific function
Organ
A combination of tissues, coordinated to perform a variety of functions
Organ systems
Organs working together as a single unit
Spiracles
Pores on the body surface of insects that open and close to allow gases to to diffuse in and out
Gill lamellae
Parts of fish gills that increase the surface area with blood flows through for gas exchange
Counter current exchange
Blood and water flowing opposite directions to maintain a diffusion gradient
Stomata
Pores on the underside of the leaf and can be open and closed by guard cells
Double circulatory system
Blood passes through the heart twice on the full circuit of the body
Arteries
Blood vessels that carry blood away from the heart
Veins
Blood vessels that carry blood back to the heart
Tissue fluid
Fluid that surrounds the cells of the body
Provides nutrients to the cells and remove waste products
Ultrafiltration
Filtration assisted by blood pressure
Apoplastic pathway
A route through the cells by which water and minerals are transported into the plant
Symplastic pathway
A route through the cytoplasm and plasmodesmata of plant cells by which water and minerals are transported
Cohesion
Water molecules stick together by hydrogen bonds
Cohesion tension
Transpiration pull on the water puts the xylem under pressure
Xerophytes
Plants adapted to living in dry conditions
Species
A group of similar organisms that can break together to produce fertile offspring
Classification
Grouping of organisms
Taxonomy
The theory and practice of biological classification
Phylogeny
The evolutionary relationship between organisms
DNA hybridisation
A technique used to determine the similarities between the DNA of two different organisms
Double strands form or the one strand from each species,closely related organisms will share complementary bases
Courtship behaviour
Signals and displays between males and females of the same species to enable successful mating to occur
Adapt
Organisms adjust to suit the changing environment where they live
Mutations
Changing the base sequence of DNA
Conjugation
One bacterial cell transfers do you need to another bacterial cell via conjugation tube
Antibiotics
Substances that can destroy or inhibit the growth of microorganisms
Plasmids
Circular loops of DNA and bacteria
Biodiversity
The variety in the living world
Including number of different species and a variety of genes and the range of habitats
What is an intron?
A non-coding section of DNA
What is an extron?
A coding section of the DNA
Antisense strand
The DNA strands that acts as a code for forming RNA
degenerate code
Many triplet codes/codons form the same Amino acid
What are somatic cells
Body cells
What to consider when deciding on a same size
Cost
Ethical issues
Large for reliability
How can you use a graph to predict data
Draw a line of best fit and extrapolate
