Science Chapter 1 Flashcards
Unicellular organisms
Organisms that only have 1 cell.
Microscope
An object that you use to study a specimen close up.
Diffusion
When particles move from an area of high concentration to an area on low concentration.
Specialised cell
A cell that is specialised to do a particular job.
A slide
A slide is something that you place your specimen onto before you study it with a microscope.
Nuclues
Stores DNA.
Cell membrane
Controls what goes in and out of the cell.
Mitochondria
Energy is released here by respiration. (Oxygen and food meet.)
Cell wall
Strengthens the cell.
Chloropast
Contain chlorophyll, which absorbs light energy for photosynthesis.
MRS GREN
MRS GREN is an acronym often used to help remember all the necessary features of living organisms: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion and Nutrition.
Multicellular organisms
An organism that is made of more than one cell.
Cytoplasm
Most chemical processes take place here.
Vacuole
They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination.
Cells
Organisms are made up of them. Some of them have different functions to others. These are called specialised cells.
Resolution
When you look at a digital image or through a microscope you see an image which has a resolution. The greater the resolution, the more detailed the image will be.
Magnification
Magnification calculations
We can calculate the length of a magnified object by using the magnification of the lens.
Length of object = length of magnified object ÷ magnification
For example, if a specimen appeared 10mm in length under a microscope with a magnification of 1,000 times, the calculation of the actual length would be:
Length of object = 10 ÷ 1000 = 0.01 mm
Rate of diffusion
How quickly particles diffuse.
Sperm cell adaptations
The head contains genetic information and an enzyme to help penetrate the egg cell membrane. The middle section is packed with mitochondria for energy. The tail moves the sperm to the egg.
Root hair cell adaptations
Long ‘finger-like’ process with very thin wall, which gives a large surface area.
Red blood cell adaptations
Thin outer membrane to let oxygen diffuse through easily. Shape increases the surface area to allow more oxygen to be absorbed efficiently. No nucleus, so the whole cell is full of haemoglobin.
Egg cell adaptations
Each egg cell has a haploid nucleus - containing only half the number of chromosomes of a normal cell nucleus. It has a large cytoplasm which contains the nutrients and mitochondria needed for mitosis (cell division) after fertilisation. And each egg has a special cell membrane which only allows one sperm to fertilise it.
Nerve cell adaptations
The main parts of the nervous system are the central nervous system - the CNS - the brain and spinal cord - and the peripheral nervous system. Nerve impulses are mainly electrical and carried in nerve cells, or neurones.
Binary fission
Bacteria reproduction
Bacteria reproduce by binary fission. This means that one cell splits into two new cells. As there is only one parent involved, this is a type of asexual reproduction.
