TERM 3/4 FLASHCARDS
Who first published the idea of cells?
Robert Hooke
Name the characteristics of all living organisms
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
What is the one exception to all organisms being made of cells?
Virus
What is the difference between egestion and excretion
Excretion is getting rid of waste and egestion is getting rid of unwanted nutrients
Where are the chromosomes found?
in the cells nucleus
What are chromosomes made up?
Very long and tightly coiled molecules of DNA
Define mitosis
The process of nuclear division giving rise to genetically identical cells in which the chromosome number is maintained by exact duplication of chromosomes
What does DNA stand for?
Deoxyribo nucleic acid
What is a gamete?
Sex cell containing half the chromosomes of a species
What is a sperm?
Male gamete
What is an ovum?
Female gamete
What is a zygote?
Fertilised egg with 46 chromosomes
What is an embryo?
Developing baby less than 6 months in mothers womb
Define meiosis
The process of a cell division where the number of chromosomes is halved to form sex cells
Define genes
Sections of a chromosome which code for one particular characteristic
Define allele
The code for a particular variety of any gene
Explain dominant/recessive alleles
Since chromosomes come in pairs each gene will have two alleles for each characteristic. The one that is shown is called the dominant allele and the one that is not show is called the recessive allele
Name the 3 possible genotypes
Homozygous Dominant “BB”, Heterozygous “Bb”, Homozygous Recessive “bb”
Define phenotype
The actual appearance of the organism
Define genotype
the gene makeup of an organism
Explain the difference between continuous and discontinuous
Continuous is any value and discontinuous is a discrete category eg. one or the other
What changes could occur during a chemical reaction?
- Colour
- Gas is given off (effervesence)
- Heat is given out or absorbed
- Gives out light
- New smells are noticed
- A solid may form in the liquid (precipitate)
Describe the qualities of an acid
Acids can be dangerous or corrosive chemicals as they react very steadily with many substances. They are known to have a sour taste.
What happens when an acid reacts with litmus paper or solution?
The litmus paper or solution will turn pink
What does Metal + Acid create
Salt + Hydrogen
List the order of reactivity for metals from most reactive
Potassium, Sodium, Calcium, Magnesium, Aluminium, Zinc, Iron, Lead, Copper, Silver, Gold
What does Carbonate + Acid create
Salt + Carbon Dioxide + Water
What is a base?
The oxide or hydroxide of a metal
What is an alkali?
A base that is soluble in water
What are the reactants and products of a neutralisation reaction?
Acid + Base = Salt + Water
What happens when a base reacts with litmus paper or solution?
The litmus paper or solution will turn blue
What is an exothermic reaction?
An exothermic reaction is a reaction that gives off energy often in the form of heat.
What is an endothermic reaction?
An endothermic reaction is a reaction that absorbs energy
What is activation energy?
The energy that is required to break up chemical bonds.
What are the characteristics of an exothermic reaction?
The energy released as the atoms join up is greater than the activation energy which leaves extra energy to be given out as heat
What are the characteristics of an endothermic reaction?
The energy released as the atoms join up is less than the activation energy which means the products must cool down