Pages in this set

Page 1

Preview of page 1
Biology B4- Homeostasis

Keeping a steady state:

Automatic control systems in the body keep factors steady, including body temperature and
water level.
Artificial control systems are similar to body control systems; they both have receptors, a
processing centre and also effectors.
Strenuous (tiring) exercises and extreme climates can affect homeostasis.…

Page 2

Preview of page 2
The brain processes information about temperature control in the hypothalamus, and
effectors (sweat glands and muscles) produce responses to keep the body temperature
Vasodilatation and vasoconstriction control the amount of blood flowing near the skin
Vasodilatation widens the blood vessels and Vasoconstriction narrows the blood vessels.
Hypothermia: causes:…

Page 3

Preview of page 3
B5- Growth and Development

The cell cycle

Cells go through cycles of growth and divisions:
I. During cell growth the number of organelles increases, and chromosomes are
II. During cell division copies of the chromosomes separate, and then the cells divide.
Cell division by mitosis produces two new cells…

Page 4

Preview of page 4
Meristem cells can re-grow whole parts of the plant, which means that gardeners can make
new plants from cuttings.
Plant hormones (auxins) affect how plant cells develop.
Plants grow towards the light; this response is called phototropism.
Auxin builds up in cells on a shoot's shady side, which make the…

Page 5

Preview of page 5
B6- Brain and Mind

A mammal's nervous system

The nervous system is made up of the central nervous system (CNS) and peripheral nervous
The CNS coordinates an animal's response via sensory and motor neurons.
Receptors and effectors can be single cells or parts of complex organs.

Nerve Impulses


Page 6

Preview of page 6
This is the end of B4, B5 and B6 summary. I hope it's helped. Thank you & Good luck in the exam.


No comments have yet been made

Similar Biology resources:

See all Biology resources »