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Flashcards in Biology Deck (128)
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What are the parts of an animal cell?
(5)

Nucleus
Cell membrane
Cytoplasm
Ribosomes
Mitochondria

1

What are the parts of a plant cell?
(8)

Nucleus
Cell membrane
Cytoplasm
Ribosomes
Mitochondria
AND
Cell wall
Vacuole
Chloroplasts

2

What's the purpose of a nucleus?

To control the cell's activities.

3

What's the purpose of a cell membrane?

To control the passage of substances in and out of the cell.

4

What's the purpose of cytoplasm?

It's where chemical reactions take place.

5

What's the purpose of ribosomes?

It's where protein synthesis occurs (where proteins are made).

6

What's the purpose of mitochondria?

It's where energy is released during aerobic respiration.

7

What's the purpose of a cell wall?

It keeps the plant rigid and supported.

8

What's the purpose of chloroplasts?

They contain chlorophyll which so needed for photosynthesis.

9

What's the purpose of a vacuole?

It's filled with cell sap / water which is there all the time.

10

What is bacteria?

Very small, single celled organisms which are only a few micrometers. They don't have a nucleus, mitochondria, chloroplast or vacuole.
Their DNA is found in the cytoplasm and controls the cell's activities.
It has a flagellum (which looks like a tail).
They contain plasmids which helps them replicate.
They also have a slime capsule.

11

What's yeast?

Single celled organisms
They have a nucleus
They reproduce by budding which is asexual an involves new cells forming from existing cells.
They have mitochondria but not chloroplasts.

12

What's a specialised cell?

A cell with a specific job to do e.g. Root hair cells (increase surface area), sperm cell (the tail), neurons carry impulses from the receptors to the CNS.
Plant cells with many chloroplasts will be photosynthesising.

13

What is diffusion?

The spreading out / moving of (liquid or gas) particles from areas where the substance is concentrated to a less concentrated area (until it is evenly spaced out).

14

Where does diffusion occur in the body and plants?

The diffusion of oxygen into the cells of the body from the bloodstream as the cells are respiring (using up oxygen).

Glucose and nutrients in the intestine

CO2 in plants

15

What determines the net movement of particles across a cell membrane?

The concentration on either side of the membrane.

16

What's a tissue?

A group of cells with similar structure and function.

17

What are the types of animal tissue?

Muscle - brings about movement
Glandular - produce substances like enzymes or hormones
Epithelial - covers the body

18

What are the types of plant tissue?

Epidermal - covers plant
Mesophyll - photosynthesise
Xylem and phloem - carry substances

19

What's an organ?

An organ is made up of several types of tissues
E.g. The stomach is made up of muscular tissue (to churn food), glandular tissue (produce digestive juices) and epithelial (cover the stomach).


(The leaf, stem and root are plant organs which contain epidermal tissue, mesophyll tissue and xylem and phloem.)

20

What's an organ system?

A group of organs which perform similar functions.

E.g. The digestive system is adapted to exchange substances with the environment. Insoluble molecules must be changed into soluble molecules.
The digestive system is a muscular tube including - glands (pancreas and salivary), stomach, small intestine, (liver bile) and large intestine.

(Duodenum is the first part of the small intestine directly beneath the stomach).

21

What's photosynthesis?

When light energy is transferred into chemical energy.

22

What's the equation for photosynthesis?

Carbon dioxide + water -> glucose + oxygen
6CO2 + 6H2O -> C6H12O6 + 6O2

23

How does photosynthesis occur?

It can only be carried out by green plants.
Chlorophyll in the chloroplasts absorbs the sun's light energy.

CO2 is taken in by the leaves and water by the roots.
Chlorophyll traps the light energy for photosynthesis.
The energy is used to convert CO2 and water into glucose (a sugar).

24

What are limiting factors for photosynthesis?

Limiting factors are anything which prevent the rate of photosynthesis from increasing.

The factors include:
Light
CO2
Temperature

25

How does temperature affect the rate of photosynthesis?

If it's cold, enzymes don't work effectively and will slow the rate however, if above a certain point (45c?) the enzymes will denature and stop working completely.

26

How do plants use glucose?

It's produced during photosynthesis which is then:

Converted into insoluble starch for storage
Used for respiration
Converted into fats and oils for storage
Used to produce cellulose which strengthens the cell walls
Used to produce proteins (and also need nitrate and mineral ions absorbed from the soil)

27

Name 3 substances used for storage in plants

Starch, fats and oils.

28

What physical factors affect the distribution of organisms?

Temperature
Nutrients
Light
Water
Oxygen
CO2

Farmers can also artificially control these factors.

29

How can you make sure an investigation is valid?

All possible variables must be controlled
Use a comparative investigation
Repeatable and reproducible measurements
The method used must answer the question
Appropriate sample size