Cells and organisation, Year 7: more practice：全部卡片
整套按顺序列出——孩子看到之前，您可以先通读一遍。
- What do we call a group of similar cells that work together to do one job?
A tissue
提示It sits between a single cell and a whole organ in size.
为什么Muscle tissue is made of muscle cells that all contract. Different tissues then combine to form an organ such as the stomach.
- What do we call a group of organs that work together to carry out a major job in the body?
An organ system
提示Your stomach and gut belong to one such group.
为什么The heart, blood vessels and blood form the circulatory system. Systems working together make up the whole organism.
- What is the jelly-like substance inside an animal cell, where many chemical reactions happen, called?
The cytoplasm
提示It fills the space between the cell membrane and the nucleus.
为什么Cytoplasm is mostly water. Many of the cell's chemical reactions happen in it, and the other parts of the cell are held in it.
- Which three parts does a plant cell have that an animal cell does not?
Cell wall, chloroplasts and a large permanent vacuole
提示One part supports, one catches light and one is full of sap.
为什么The wall gives support, the chloroplasts carry out photosynthesis and the vacuole stores cell sap and keeps the cell firm.
- How does the long, thin shape of a nerve cell help it do its job?
It can carry electrical messages over long distances around the body
提示Think about what the cell must reach.
为什么Nerve cells carry electrical impulses between the brain and the rest of the body. Their long fibres let one cell link places far apart.
- Muscle cells contain a large number of mitochondria. Why?
They release lots of energy for the muscle to contract
提示Think about the fuel a working fibre needs.
为什么Mitochondria are where respiration releases energy. A muscle cell that contracts again and again needs a plentiful supply.
- You can smell dinner cooking from another room. Which process spreads the smell through the air?
Diffusion
提示Particles spread out from where there are lots of them.
为什么Scent particles leave the food, where they are crowded, and move randomly into the rest of the air where there are few.
- What happens to the rate of diffusion when the temperature rises, and why?
It speeds up because the particles move faster
提示Think about what warmth does to how fast tiny pieces travel.
为什么At higher temperatures particles have more kinetic energy, so they spread out faster. This is why a smell reaches you sooner in a warm room.
- A cell is 0.05 mm long. In a drawing it is 5 mm long. What is the magnification? (number only)
100
提示Divide the drawing size by the real size.
为什么Magnification = image size ÷ real size = 5 ÷ 0.05 = 100, written ×100.
- A photograph of a cell is 40 mm long and the magnification is ×50. What is the real length of the cell?
0.8 mm
提示Rearrange the formula so the real size is the subject.
为什么Real size = image size ÷ magnification = 40 ÷ 50 = 0.8 mm.
1★ KS3-BIOL-CEL-0039
2★ KS3-BIOL-CEL-0040
3★ KS3-BIOL-CEL-0041
4★ KS3-BIOL-CEL-0042
5★ KS3-BIOL-CEL-0043
6★ KS3-BIOL-CEL-0044
7★ KS3-BIOL-CEL-0045
8★ KS3-BIOL-CEL-0046
9★ KS3-BIOL-CEL-0047
10★ KS3-BIOL-CEL-0048