Semester 2 Science Revision Flashcards
What is an element
It is made up of only one type of atom.
Give 3 simple statements to define energy
Energy is the ability to do work.
Energy is needed to make things change or move.
All objects have energy.
What is kinetic energy
The energy of movement.
What are 4 types of kinetic energy
heat energy, light energy, sound energy, electrical energy
What is potential energy
Energy that is stored within objects.
Give 4 types of potential energy
gravitational PE, elastic PE, chemical PE, nuclear PE
What is the law of conservation of energy
Energy can’t be created or destroyed.
Energy can only be transformed from one form to another.
Energy may be transferred but is never lost.
What happens to the energy of an object when heat is added
Energy is added to its particles
What is conduction
Conduction is a type of heat transfer that occurs when two solid objects are in direct contact.
What is convection
The transfer of heat from one place to another due to the circular movement of fluid.
What is radiation
Transfer of heat through infrared waves.
The particle model
All substances are made up of tiny particles.
The particles are attracted to each another.
The particles are always moving.
The hotter something is the faster its particles move.
What is an atom
building block of matter
What is a pure substance
It is made up of only one type of chemical substance.
What is a compound
It is made up of 2 or more types of atoms.
What is a metalloid
A non-metallic substance that has some of the properties of both metals and non-metals.
What is a monatomic element
An element that is made up of many individual atoms.
What bonds do compounds form
ionic bonds, covalent bonds
Covalent bonds
atoms share electrons
Ionic bonds
atoms lose or gain electrons
Homogeneous mixture
Contains substances that are not evenly distributed and do not separate easily.
Heterogeneous mixture
It is not blended evenly and can be separated into its parts
Give 5 pieces of evidence of a physical change
change in shape, expansion or contraction, change in state, mixing or dissolving, a non-permanent colour change
Expansion
When particles are exposed to a higher temperature, absorb energy and convert to kinetic energy.
Contraction
When a substance cools, particles lose energy.
Chemical change
new substance is formed, often irreversible
Physical change
When the physical properties of a substance change, but no new chemical substance is formed.
Give 5 pieces of evidence of a chemical change
new substance is formed, permanent colour change, often irreversible, gas is being formed, change in temperature
Exothermic
Reaction that release energy.
Endothermic
Reactions that take energy from their surroundings.
Reproduction
Process by which parents produce new individuals.
What are the two basic methods of reproduction
asexual, sexual
In sexual reproduction what is the male gamete
sperm
In sexual reproduction what is the female gamete
Ovum
Meiosis
Is the process that forms gametes.
What is the process that forms gametes?
Meisosis is when a single cell divides to produce 4 new cells which are non identical
Internal fertilisation
occurs inside the body
External fertilisation
occurs outside the body
male gamete of plants
pollen
female gamete of plants
ovule
what reproductive structures do flowering plants contain
male and female
stigma
site for pollen to be deposited
style
connects stigma to ovary
ovule
the name for the egg in plants
flower stalk
supports and displays the flower
petal
coloured parts that attract animals to allow for pollination
anther
produces pollen that contains the male gamete
filament
holds the anther
sepal
covers the flower in the bud and protects it
1st step for pollination
Pollen is produced in the anther
2nd step for pollination
The pollen is transferred to the stigma through wind, insects etc.
3rd step for pollination
The pollen develops a long tube. This grows down through the style, to the ovary, to the egg.
4th step for pollination
The male gamete drops down from the pollen, along the tube, to the female gamete in the ovary. These gametes fuse to make a seed
A fruit
is the remains of the ovary, plus all of the seeds within
Puberty
A time in life when one becomes sexually mature and becomes able to reproduce
Oestrogen
- stimulates release of egg from ovaries
- responsible for female secondary sexual characteristics
- develops uterus lining
- produced in ovaries
Testosterone
- stimulates production of sperm in testes
- produced in much smaller amounts in females
- responsible for male secondary sex characteristics.
Progesterone
- produced in ovaries
- thickens lining of uterus
- stimulates release of eggs from ovaries
- drop in levels causes menstruation and causes lining to shed
- production also stimulated by implantation of a fertilised egg in the uterus lining
Stages of menstruation in order
- Follicular phase
- Ovulation
- Luteal phase
- if egg is not fertilised ovum disintegrate and lining sheds.
Follicular phase
ovum and uterus lining develops
Ovulation
ovum is released from ovary
Luteal phase
ovum travels through fallopian tube and has potential to be fertilised
4th phase
if egg is not fertilised ovum disintegrates and lining is shed
Menstruation
- Increase in Oestrogen and Progesterone leads to lining being built
- Decrease in Progesterone leads to lining being shed
- shedding of blood is menstruation
- around 28 days
Indicator of puberty for females
when first ovulation occurs
Indicator of puberty for males
when first fertile sperm are produced
Bladder
Male- holds urine for excretion
Seminal Vesicle Gland
Male- releases liquid which mixes with sperm to form semen
Prostate
Male- produces alkaline liquid that neutralises the acidic conditions of the vagina
Sperm Duct
Male- tube that transports sperm from testes to penis
Testes
Male- After puberty, produces sperm continuously for the remainder of the males life
Scrotum
Male- protective sac of skin that holds the testes and responds to temperature change.
Urethra
Male- tube through which semen and urine leaves the body
Penis
Male- contains erectile tissue and urethra
Ovaries
Female- produces ova (eggs)
Vagina
Female- where semen enters the body and the passage through which babies are born.
Cervix
Female- during child birth it dilates (opens up) to let the baby out
Fallopian tube
Female- Ova (eggs) travel alone this tube to the uterus
Uterus
Female- Ovum is fertilised with sperm. The ‘new cell’ implants itself and grows into a baby.
Combustion reactions
Exothermic reaction, involves burning/exploding a substance in oxygen.
Examples of asexual reproduction in animals
Budding, Fission, Parthenogenesis
Copulation
Sperm are ejaculated from the penis into the vagina near the base of the cervix. Sperm then passes through the cervix into the uterus and swims towards the fallopian tubes. Most sperms die along the way.
Fertilisation
Sperm race to the egg. The nucleus of the first sperm to make it inside fuses with the nucleus of the egg.
What is a fertilised egg called?
Zygote
Stages of baby development
- Zygote
- Embryo
- Foetus
Zygote
First cell that forms. This cell continues to divide and attaches to the uterine wall.
Embryo
- 10 days after fertilisation implantation of the blastocyst occurs
- Placenta develops
- After 8 weeks baby is referred to as an embryo
- develops spinal cord, heart, liver, lungs
Foetus
- After 9 weeks referred to as foetus
- starts to resembles a human
- arms and legs develop
- genitals (penis, vagina) develop
- Start to grow inside the womb
3 properties of Non-Metals
State at room temperature- solid, gas or liquid
Lustre- Usually dull
Conductivity- can’t usually conduct electricity or heat.
3 properties of Metals
State at room temperature- solid (except mercury)
Lustre- shiny when polished
Conductivity- conducts electricity and heat
