Science - Cycle Test Term 1 Flashcards
What does Magnification mean?
The number of time larger the image we see is.
What is a Specimen?
The sample you are trying to see.
What does resolution mean?
The detail shown in the image.
Who created the first microscope?
Robert Hooke
What is the eye piece lens
The first lens we look through.
What is the objective lens?
The second lens that magnifies the image. You can rotate it for different magnifications.
What is the stage?
The part that supports the specimen.
Adjustable distance to objects.
What is a slide?
The piece of glass that holds the specimen.
How do you calculate the magnification of an image?
Magnification of the eyepiece lens X Magnification of the objective lens = Magnification of the image
What are ribosomes?
This is where protein is produced.
What is the Nucleus?
The brain of the cell, controls the cell, it contains DNA (Genetic material).
What is DNA?
Exists in the nucleus, it is in compact shapes called chromosomes.
What are chromosomes?
The ‘X’ shape that DNA is stored in.
What is a cell membrane?
Controls substances going in and out.
What is a cytoplasm?
A jelly like substance where chemical reactions take place.
What is a cell wall?
Protects the cell and maintains the shape of the cell.
What is a mitochondria?
Where aerobic respiration takes place.
Bean shape.`
What is a chloroplast?
Contains chlorophyll. This is where photosynthesis takes place.
What is a vacuole.
Stores cell sap. It helps hold the cell together.
What is cell sap?
Contains sugars, amino acids, waste substances (such as tannins), and mineral salts.
What is chlorophyll?
A green substance that is in chloroplasts, that is needed for photosynthesis.
What are the 2 types of cells?
- Prokaryotic cells
- Eukaryotic cells
What is a prokariotic cell?
= A single celled organism.
- Are smaller and simpler
- No nucleus
- DNA is in plasmids
- Mainly bacteria
What is a plasmid?
A small circular DNA molecule found in bacteria and some other microscopic organisms.
What is a Eukaryotic cell?
= Complex and include all animal and plant cells.
- Has a nucleus.
- More complex than Prokaryotes.
- Organelles
What is an oraganelle?
Subcellular structures.
What is a specialised cell?
Cells that are adapted to perform a certain job.
What is the adaptations of a specialised cell?
- Shape
- Size
- Structure
- Content
Provide some examples of specialised cells?
- Ciliated Epithelial Cells
- Red blood cells
- Root hair cells
- Sperm cells
- Egg cells
What are the adaptations of a sperm cell?
- Acrosome = it is at the front of the sperm’s head and contains enzymes that digest the egg cells membrane.
- Long tail = To help the sperm swim to the egg cell.
- It has a lot of mitochondria, arranged in a spiral shape, at the top of the tail (middle section of the sperm) to provide the energy needed for the tail to swim.
- Has a haploid nucleus
- Streamlined shape to help it swim efficiently in the uterus.
What are the adaptations of an egg cell?
- Cytoplasm contains nutrients to feed the embryo.
- Has a haploid nucleus.
- Membrane changes structure straight after fertilisation to prevent any more sperm cells entering to ensure that the offspring end up with the right amount of DNA.
What are the adaption of a muscle cells?
- Many mitochondria as they need more energy than other cells.
What is digestion?
The process of breaking down the food to extract the nutrients.
What is a micronili?
A microscopic cellular membrane protrusions that increase the surface area for diffusion and minimize any increase in volume.
What is a Gamete?
Reproductive cell.
What are some examples of gametes?
- Egg cells (Ovum)
- Sperm cell
What does fertilisation mean?
The process of the sperm and ell cell combining to form an embryo.
What is an enzyme?
Special substance that breaks down long molecule from the egg membrane fond at the top of the sperm cell.
What is a diploid nuclei?
A nucleus with a full set of chromosomes.
What is an epithelial cell?
- A cell that lines the surface of an organ.
- Some have cilia.
What is a haploid nuclei?
A nucleus with half the number of chromosomes as in a diploid cell.
What is cilia?
- A hair like structure on the top surface of a cell.
- In the uterus it moves the egg along the fallopian tube.
- In the nose and lungs it traps dust and dirt from entering during respiration.
What are the specialised cells for digestions?
- Cells in the small intestines have increased surface area for the absorption of nutrients.
- Microvilli (membrane with tiny folds) increase surface area.
- More ribosomes to produce more proteins to produce more enzymes to help digest and absorb food.
What is a ciliated cell?
A cell that has little hair like structures called cilia.
What is a acroscome?
The pointy tip of the sperm cell.
What is the plasmid?
- One loop of DNA
- Controls cell activities
What is the cytoplasm?
A jelly like substance where chemical reactions take place.
What is aa flagellum?
- Tail like structure that helps bacteria swim
- Many bacteria have them but not all
What is a ribosome?
- Produces proteins
What is a cell wall?
A flexible coat around the cell.
What do bacteria not have?
- Mitochondria
- Nucleus
- Chloroplast