Growth And Development Flashcards Preview

Biology Module 3 > Growth And Development > Flashcards

Flashcards in Growth And Development Deck (18)
Loading flashcards...
1
Q

Describe how to make a stained slide of an onion cell

A
  • use tweezers to peel a thin layer of skin tissue from an onion
  • place the onion tissue onto a microscope slide on top of distilled water
  • add a drop of iodine solution to the tissue and carefully cover the slide
  • you should be able to see the parts of an onion cell at X100 magnification
2
Q

What is growth measured as?

A

An increase in height, wet mass or dry mas

3
Q

Describe the process of growth as cell division followed by cells becoming specialised

A

The cells specialise or differentiate at an early stage into different types of cell to form tissues and organs. All parts of animals grow, but growth eventually stops

4
Q

When do animals and plants grow?

A

Animals grow in the early stages of their lives whereas plants grow continually

5
Q

Understand that all parts of an animal are involved in growth whereas plants grow at specific pars of the plant

A

Animals - all parts are involved in growth

Plants - grow at specific parts of the plant

6
Q

Describe the difference between the arrangement of DNA in a bacterial cell and a plant/animal cell

A

Plant cells keep their DNA inside the nucleus but bacterial cells do not have a nucleus so their DNA floats as circular strands

7
Q

What do bacterial cells lack?

A

A ‘True’ nucleus
Mitochondria
Chloroplasts

8
Q

What is the best measure of growth?

A

Dry mass as it is the most accurate method

9
Q

Describe the main phases of a typical growth curve

A

Growth in organisms usually follows a typical ‘s-shaoed’ pattern

10
Q

Identify the rapid growths in humans

A

In human growth there are two phases of rapid grwoth, one just after brith and the other in adolescence

11
Q

Explain the advantages and disadvantages of measuring growth by:

  • Length
  • Wet mass
  • Dry mass
A

L - easy and rapid measurement. Increase in mass might occur with no increase in length
WM - quite easy to measure. Water content of living tissue can be very variable and may give a distorted view overall
DM - most accurate method. Destructive as removal if water kills organisms

12
Q

Explain why the growth of parts of an organism may differ from the growth rate of the whole organism

A

This is because the circulation of blood is vital to the growth and development of the embryo and therefore needs to be prioritised

13
Q

Explain the difference between adult and embryonic stem cells

A

An embryonic cell can develop into any cell in the body without limit to replenish. And an adult cell is only able to mature into a specialised tissue cell from which tissue the cell is positioned

14
Q

Explain why plant growth differs from animal growth

A
  • animals tend to grow to a finite size but many plants can grow continuously
  • plant cell division is mainly restricted to areas called meristems
  • cell enlargement is the main method by which plants gain height
  • many plant cells retain the ability to differentiate but most animal cells lose it at an early stage
15
Q

Discuss issues arising from stem cell research in animals

A
  • embryos have the potential to become a human being, so it is wrong to experiment on them
16
Q

How can stem cells be obtained and can they be used for?

A

Stem cells can be obtained from embryonic tissue and could potentially be used to treat medial conditions

17
Q

What can undifferentiated cells called stem cells develop into?

A

Different cells, tissues and organs

18
Q

Describe the functions of the part of a plant cell

A
  • vacuole containing cell sap and providing support

- the cell wall, made of cellulose to provide support