Combined Science Flashcards
What is diffusion?
the movement of particles from a high concentration to low.
What is the equation for magnification?
magnification=image/actual
What is a prokaryotic cell?
A cell that does not contain a nucleus e.g. bacteria cell
Why is electron microscope better than a light electron
they have a higher magnification.
they have a higher resolution
Where are the chromosomes found?
they are found in the nucleus
How many pairs of chromosomes are in the human body?
23 pairs
What do chromosomes carry large amounts of?
Genes
What Are the different ways cells can be divide?
Mitosis and Meiosis
Name 1 function of mitosis?
essential for growth and development of multicellular organisms.
It helps for growth and repair.
What type of cell is a haploid cell?
A gamete (it holds half of the genetical material.)
What are the stages of meiosis?
1) DNA replicates
2) they line up at the centre of the cell
3) the chromosomes are pulled apart and splits into 2 cells (the DNA is different)
4) they reline up at the centre of the cell.
5) The arms are pulled away
6) the cell splits in half. these become genetically unique.
What are the steps in mitosis?
The DNA replicates to form 2 copies of chromosomes.
2) one set of chromosomes are pulled to each end of the cell
3) the cytoplasm and membrane divide to form 2 identical cells.
What is active transport?
the movement of substances against their concentration gradient
What was John Dalton structure of an atom?
He described as a ‘solid sphere’ AND different spheres were made up from different elements.
What did Bohr find out? What was his theory supported by?
He found out that all electrons are contained in a shell He proposed they orbited in fixed shells
he did many experiments to prove this theory.
What did Rutherford do to show the plum pudding model was wrong?
The Alpha Particle Experiment
this was sending positive charged particles at a thin sheet of gold foil. he found out that the particles did go through but many deflected and some deflected backwards.
What did JJ Thompson find out?
he found out that atoms were not a solid sphere and shows that their must be a negatively charged particle (electron)
(plum pudding model)
What did Rutherford also found out?
particles that have the same charge as a hydrogen particle were positive (protons)
What experiment did James Chadwick carry out?
An experiment that there were neutral particles (neutrons)
What are the 3 main differences between a plant and animal cell?
plants have cell walls, chloroplasts and permanent vacuole.
animal cell have bones instead of cell wall.
What is the definition of osmosis?
the movement of water molecules from a partially permeable membrane across a high to low concentration
What do 2 gametes form?
Diploid cell
What are the five things that are usually in an animal cell?
Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes.
What is a bacteria cells true nucleus?
they have a singular strand of DNA that floats freely in the cytoplasm
